Tuesday 26 May 2020

Buying Japanese V-twins



V-twins usually conjure up visions of noisy, fragile Ducatis, queasy Harleys or hardcore old Vincents, so it comes as something of a surprise to reflect on the sheer range of Japanese V-twins that are available. Custom cruisers abound on the back of Harley’s success but never really catch the elemental spirit of the American machine; instead afflict some pretty nasty handling traumas on the European rider.

Sporting V-twins, until very recently, were ignored, unless you include the strange Yamaha XZ550 or the old VT250 and its successors, although the American market had the benefit of the Bros 400 and 650 V’s, based on our own most moderate Revere. The only area where the Japanese really played their hand well was in the serious motorcycle sector, machines like the CX500 and VT500 managing to combine ruggedness with practicality and even a little bit of fun.

Perhaps the nearest the Japanese came to a serious motorcycle was the Suzuki VX800. This might seem a strange exclamation but is mostly centred around the fact that the engine’s a marvellous piece of engineering, like most Japanese V-twins screaming out for a proper chassis rather than the normal custom nonsense. Though watercooled, the combination of engine fins and a slim radiator makes this much less of an offence to the purist, whilst it allows the high quality of engineering to shine through.

Certainly, in Intruder custom guise the engine’s never pushed enough to test its mettle, but even in VX form such is the excess of torque that there’s really nothing to be gained from trying to screw it into the red. Not that the engine needs mild treatment to survive, it is one of the toughest V-twins around. Good for at least 50000 miles, possibly lots more.

Although the VX chassis is a large improvement over the custom stuff, this ain’t saying very much. Far too long and heavy to really take advantage of the gutsy nature of the 800cc motor, it leads more to inhibition than exhilaration, and such is the wholeness of the package that there’s no easy way to update it. Slipping the engine into some old British chassis, ending up with a machine that weighs way under 400lbs, is really where it’s at, although the presence of the shaft drive limits such engineering excursions.

Quite a few VX’s ended up wrapped around trees or impaled on cars - it’s much more important to look for signs of craftily hidden crash damage than to worry over the chances of buying one with an engine on the way out. Though it’s worth, as with most Suzuki’s, checking out the condition of the electrics and making sure the clutch ain’t rumbling on its bearings. Prices can be silly for recent VX’s, especially in dealers, but low mileage examples, a few years old, can be picked up on the private market for £2000 to £3250.

Another Japanese V that never quite made it was the 600/650 Revere. This was a machine with a severe identity crisis. Its engine never really lived up to its high tech, single-sided swinging arm chassis, having a mildness in laying down its power that only the civilizing influence of Honda could inflict on a medium sized V-twin. It wasn’t until the 650cc version was introduced at a bargain price that the machine found its niche as a cheap, ultra tough despatch hack, and sometimes mild tourer.

Many DR’s managed to get them around the clock, which says a lot for their basic toughness but doesn’t really commend them on the second hand circuit. Some real dodgy buys out there, with ruined chassis bearings (not recommended on the single sided swinging arm), sagging suspension, creaking brakes and inflammatory electrics. Not to mention the possibility that the mill’s about to start expensively knocking.

For sure, some Revere’s led a mild, happy life as a tourer under the hands of a mature rider but it’s easy enough to buy the wrong kind of bike. Hacks start at £500 and £2000 should buy an immaculate example of the breed. It’s possible to buy one for £1000 that still has a useable engine and just needs a bit of attention to the chassis and consumables. Signs of a reasonable engine are usually found in the slickness of the gearbox and clutch, lack of rumbles and knocks from the engine, and a clear exhaust.


The VT500 was used in a similar way to the Revere, though being older it’s been subjected to even more mileage and abuse. The valve gear and clutch are the weakest areas of the generally tough engine, though that old Honda bogey, naff camchains and/or tensioners, can also rear their ugly head without much waming (especially if the tensioners have been bodged by a crafty owner).

Chassis rot, brakes apart, isn’t a problem until 50,000 miles, or so, but after that it can go into a 
rapid decline unless much tender loving care is applied. Good chassis spares (don’t even think about the brakes) are becoming rare in breakers but forks and brakes off newer motorcycles are, anyway, worth fitting. The rest can be kept going by a bit of mixing and matching. Expect to pay around a grand for something useable.


Even more horrid and horrible than an old VT, the CX500’s now long in the tooth and mostly degenerated into that sad area of built-in obsolescence. Actually, it’s so far gone that it’s rapidly becoming a cult bike and the engine has even ended up powering the odd chopper; not so much a case of passing the sick bucket as gawping in sheer disbelief.

The CX started off poorly, with a spate of exploding engines, and never did entirely shake off the reputation for doing in its camchain (it actually uses pushrods but in a throwback to the days of British gore drove the camshaft by a short chain). Come 50000 miles, everything from the water pump to the main bearings are likely to explode, but the odd one has been rebuilt enough times. to get it around the clock.

This means buying any CX, though the later 650 is generally regarded as the toughest of the bunch, is fraught with danger. Like many an old British wreck, the CX can be bodged so that it stays together long enough to get it out of the street. Paying more than 500 notes isn’t really on, though there are undoubtedly some around at silly prices.

Whereas the VT had a merely adequate chassis that never turned nasty, and the Revere could be close to sublime after some minor suspension mods, the poor old CX was described as a bit of a blancmange, something more likely to gain approval from the more zany rollerblade enthusiast than from a biker. True, the combination of pressed steel frame in all its cheap production cost glory and the massive bulk of the engine provided a rigidity that when equipped with decent forks and shocks fair transformed the feel of the brute, but it never elevated itself to true excellence. Something to do with too much mass too high up. Not even equipping later models with Unitrak back ends was able to really invigorate the handling.

An even greater curiosity than the poor old CX, but one that never sold in any great quantities despite the fact that early ones didn’t explode well before the warranty was up, was the Yamaha XZ550. No wonder Yamaha subsequently ran off to the relatively safe shores of the custom scene. On the face of it, here was a water cooled, DOHC V-twin that had everything going for it. Well, OK, the styling was a bit ugly, topped off by a massive carbuncle of a radiator. What let the XZ down was the delivery of its power that was as variable as Welsh weather. Some bikes, some days, ran rather well. Other times, the engine felt choked and lackadaisical, with the general upshot that most owners wanted to take a hammer to the swine.

Mixed in with the petulant power delivery was a tendency to throw in the odd speed wobble, a combination in the wet that made for brown trouser time. Hatred of the bike led to general neglect which led to top end hassles, and if oil changes were seriously ignored a blown bottom end. All of these potential problems are easily sussed by listening for the expected rattles, Knocks and rumbles.

There are a couple of decent examples still floating around the UK. At this age it’s easy to tell the good ones from the bad - quick starting and smooth power delivery being the most pertinent areas of concern. The gearbox was never slick, something to do with the odd power pulses from the V-twin engine but missed changes and an excess of false neutrals are signs of high mileage. Around £500 to £750 for something that’s still working reasonably although dealers will try to off-load them on the unwary for as much as two grand! The odd grey import XZ400 also turns up, seems to be a more effective tool than its bigger brother, for under a grand.

Yamaha’s other attempt at a serious V-twin was the TR1. A 1000cc’s worth of butchness that looked suspiciously like they’d bunged two SR500’s top ends on to a common crankshaft, although in reality the almost square bore and stroke of the SR was exchanged for a short stroke arrangement of 95x69mm to knock out a claimed 70 horses at 6500rpm. Somewhere along the line quite a lot of this power did a disappearing act, riders hard pressed to get the V beyond the 110mph mark.

Because the TR1 uses its V-twin engine as a major part of the frame (there aren’t any down tubes) riders are cast back into an era when each and every explosion of the combustion process is communicated to them, although never in the more urgent and insidious manner of a sixties British vertical twin. After a time to acclimatize it all becomes quite pleasant, adding an element of much needed reality to the motorcycle experience.


Nearly all TR1’s will end up clattering their inadequate electric starters, though there is a fix for this. If it hasn’t been done expect it to go down any time soon. Longevity of the TR1 engine’s good if regular maintenance is done and the bike’s ridden in the spirit of its engine - ie with more regard to the fact that its torque peaks at a mere 5000 revs than with any wantonness on the throttle.

Given abuse and neglect, it can be on the scrapheap in as little as 30000 miles. Even sensible riding will call for camchains and tensioners before 50000 miles, when the pistons and rings may well be in a dubious state. Most have now been rebuilt to some extent but they seem to respond well to new parts and can keep going right around the clock. Genuine low milers are usually revealed in the slickness of their gear change (though this may go off if chain maintenance is totally ignored, as it’s encased in a full enclosure with its own supply of oil!).


Handling can be made reasonable with the usual suspension upgrades but the front disc’s a nasty piece of work with the expected wet weather lag and general lack of power; anything newer is better. The Vincent inspired rear end can suffer from rapid bearing wear, more down to the pressure of near on 500Ibs of mass and the minimal mudguarding than anything else. TR1’s change hands for around the grand mark on the private market.

The TR1 soon became the XV1000 Virago, with lots of detail engine changes, five less horses but torque peaking out at a mere 3000rpm. This was stomp city without any concessions towards serious motorcycling, the whole caboodle set up to attract buyers from the Harley camp. Where the TR1 could be pushed reasonably hard, the Virago was limited by its strange steering geometry, although it had much better twin disc brakes. Twin shocks replaced the TR1’s mono-track back end, to little effect although there were no longer any short-lived bearings to worry about.

The bike shared with its 750cc sibling a reasonably effective shaft drive and a better build of starter motor. As the weight difference between the two machines was a mere 16lbs, there seems no reason to favour the much milder 750 unless the rumbustious nature of the bigger bike doesn’t inspire. The XV1000 was eventually stroked out to the 1063cc, as in the 1100 Virago, although the extra capacity further emphasized the torque, power dropping back to a mere 60 horses at 6000 revs.

Some Virago owners go completely mad, chroming everything that can be chromed until a pair of shades become compulsory. There are some bikes out there with expensive chrome and accessories galore that fetch little more than the standard machine on the used market. £4000 maximum for something newish and immaculate, down to £800 for a near rat; around two grand for a reasonable example with lots of chrome goodies.

Yamaha’s most popular V in the UK’s the 535. This is a thoroughly sensible motorcycle blighted by its custom styling; it would probably sell even better if the wannabe-chopper nonsense was ditched in favour of conventional steering geometry and a proper set of handlebars. The XV535 shares little engineering with Yamaha’s bigger Vs, instead is derived from the Jap market (and grey import) XV400, although all models share the commendable design of using the engine as a stressed frame member. The 535 makes a mere 46 horses at 7500rpm but is saved from instant obscurity by only having to drag 400Ibs (almost miraculously light for the normal weighty Japanese customs but still pretty pathetic for 1997) and churning out a modicum of torque. By contrast, the 400 model needs revs to get anywhere reasonably fast.

Handling’s safe rather than inspiring, mostly down to the stability afforded by the large nineteen inch front wheel and less radical custom geometry than most such devices. Unfortunately, there’s no easy way of transforming the handling into something better, but its general limitations do mean that the engine has a relatively easy life; no real troubles until 40000 miles when general wear and tear begins to take its toll.

For some reason - perhaps clocking gives an unfair impression - XV400s don’t last so well as their bigger brothers, can be in serious trouble at as little as 30000 miles. On both bikes rattling clutches, struggling gearboxes and clattering top ends are sure signs of engines on the way out. Engine spares for the 535 are plentiful in breakers but rare for the 400 (the engines share neither the stroke nor bore, though many minor parts are common). Expect to pay £3000 for a really excellent 535 - and £2000 for a low mileage 400. Older 535’s can go for under a grand and some of them are merely a bit faded rather than in any kind of mechanical trouble - purely down to the cosseted life many machines lived.


Yamaha have recently burdened the market with a 250cc version of the Virago but pricing is way over the top compared to recent grey imports at less than two grand (it’s been a Jap market model since 1989). Weight is reasonable at 310Ibs but less than 20 horses doesn’t inspire.

Far more amusing, and trickling on to the grey import market, the SRV250 uses the Virago’s engine 
(tuned to 27 horses) in a chassis inspired by the old Norton Featherbed; a compulsive concoction of classic styling and Jap engine technology that really needs to run the 535 engine to make sense in the European market. Good examples fetch around £2500, although one viewed had obvious crash damage, including a bent top frame tube. So take some care!


Whereas Yamaha stuck with their air cooled technology, Suzuki used water cooling in their 600 and 800cc customs but stayed with air cooling for their monster 1400 Intruder, against all good engineering practice. The 1400’s a lesson in how to extract the maximum amount of torque from a big twin, peaking at a mere 3200 revs; power a reasonable 70hp at 4800rpm. Because the rear cylinder’s somewhat obscured excess finning and an oil-cooler are needed, the whole bike bulking up to over 520lIbs.

Here’s an engine that’s screaming out for a proper chassis, single carb and throwback sporting pretensions. It’s a great old slogger that gives most Harleys a run for their money but the handling’s largely hindered by the lack of ground clearance and weird steering geometry.

Luckily, the three-valve per cylinder, OHC engine is as tough as they come - from a combination of its excessive torque and the odd handling making it pointless to thrash, and, of course, the general excellence of its engineering. Yet another great missed opportunity but if custom cruising actually turns you on then a great buy at £3000 to £4000 for the really nice stuff.

The 800 Intruder uses water cooling and four valves per cylinder to produce-a more modern, less idiosyncratic engine that works better (but not really well) in the VX800. Again, toughness is excellent. Although power and torque are down compared to the 1400, so is the mass at 440lbs, giving the 800 just as effective forward motion with easier handling and a smoother time. Handling and braking aren’t likely to inspire, the latter likes to rot after a couple of British winters. Around £3000 will secure a reasonable Intruder.

All that was said about the 800 goes for the 600 Intruder but it obviously lacks the sheer grunt of the 800 (only having a pathetic 45 horses to hand) whilst still having to cart the same mass along. Only cheaper insurance really commends it, a bit of a pointless bike in view of the worthiness of its bigger brothers. It’s quite difficult to find any of the Intruder engines in breakers, probably because few people ride them in the winter when the chances of sliding off are greatly enhanced, which makes using one of these excellent engines in a special difficult.

Honda used the technology of their VN1500 to produce custom 600 and 750cc variants. The only thing they had going for them was engine toughness The oddest, and maybe even the best, version was the Africa Twin, based on a 742cc, 52 degree version of the VT mill. An interesting mix of power and torque, reasonable handling though excessive weight and horrible styling, gave lots of on the road fun. You won’t get much change out of three grand for a reasonable example.

Similarly, the 600cc Transalp had adequate performance and chuckability but was limited by general ugliness and lack of efficiency. Way overpriced when new, £2500 should purchase a recent one whilst a well shagged ten year old example fetches around £750. General engine and chassis wear and tear after 45000 miles is more of a problem than any chronic faults (though disc brakes and camchain tensioners are always worth checking properly).

The VT600C Shadow’s the usual custom nonsense, no worse nor any better than other Japanese offerings. Power’s way down to a mere 40 horses in favour of maximising the torque at a low 3500rpm. Engine toughness, as might be expected from such a mild mill, is generally good. Handling and performance don’t overwhelm but only scare when the going gets fast. Priced at £2500 to £4500.

The Japanese market had a 400cc version from as long ago as 1983 (there was also a custom CX400 at the same time!). Grey imports from as little as £1500. Also on the import circuit, the rather excellent 400 and 650cc Bros — basically Reveres with alloy frames, chain drive and tuned engines - £2000 to £3000. Yet more import options exist in the 250 Xelvis and Spada, evolutions of our own VT250, which ended up making 40 horses and weighing a mere 3 10lbs in the Spada. £2000 to £2750 on the grey import circuit.

Honda went way over the top with the VT1100 Shadow, a 5701b and 80hp lump of V-twin excess that’s popular with poseurs. Around £5000. No sooner had this monster been launched than they created the VRX400, a wholly sensible implementation of the VT400/500 series with what could loosely be termed flat track styling; but hefty at 420lbs and way down on power at 33 horses.

A huge range of V-twin motors, then, but the Japanese haven’t got a clue about housing them in proper motorcycle frames, nor realising that the main design element to go along with their massive grunt should be minimal mass - say 350lbs for a 1000cc V. The latest, race replica 1000cc V-twin, offerings from Honda and Suzuki go some way to affirming the sporting pretensions of Jap V-twins but lumber the bikes with all the silly impracticalities and high running costs of the Japanese fours. The best thing to do with one of the big custom V-twins is to rip its engine out and find or make a decent chassis that will bring it into the modern world. Good hunting!




Dick Lewis



Friday 22 May 2020

Buying Japanese twins


For most of the sixties the British factories dominated the motorcycle scene with a series of 500 and 650cc twins. Light, fast and economical, eventually their lack of development, excess of vibration and dubious reliability allowed the Japanese to take over as the main producers of motorcycles. Honda started the ball rolling with a series of OHC engines that had far superior engineering, as well as more power per cc. Most other Japanese companies used these strong, if basic, twin cylinder designs as the inspiration for their own later efforts.

In the seventies and eighties, Honda mostly neglected the genre in favour of their four cylinder bikes. Only belatedly catching up with their rivals when the water-cooled CB500 made an appearance in 1994. Even then its top end performance wasn’t up to the market leader, the GPz500S - a bike which basically messed up by failing to develop its power to weight ratio, or keep its price at a competitive level.

Amazingly, in the middleweight vertical twin game, only the CB and GPz offer any real signs of development, though compared with the way the four cylinder bikes have evolved, they are both pretty abysmal. Of course, Yamaha have managed to retain their hold on the big twin market, having started with the XS650 in the early seventies and eventually emerging with that most powerful of twins, the TDM85S0. This is a bit of a mess engineering-wise with a silly separate oil tank and an excess of balancers, but nevertheless manages to knock out an incredible amount of torque and be reasonably smooth.

Suzuki, meanwhile, climaxed early in the game, not doing much to the development of the breed since the GS400 emerged in the late seventies. For sure, the GS500E and GS450 aren’t bad bikes but they just aren’t up to the standards of the other machines.

Suzuki also made a 650 twin, the Tempter, which is cheaply available on the grey import circuit and not bad value if you don’t object to the mild custom stance. Spare parts are difficult, although many Continental countries, such as Belgium, had them on offer so it’s not a total disaster. They tend to be a bit tatty around the edges but quite an interesting trip once under way, with better performance and handling than the XS650. Reasonably priced at around £1250. And, yes, they do suffer from the infamous Suzuki electrics!

Of all the modern machines, the one to most effectively merge speed, lightness, smoothness, reliability and general performance’s the Kawasaki GPz500. Its excellent aerodynamics allows it to make the most of its 60 horses - 125mph, would you believe? Acceleration ain’t quite arm wrenching, handling of the sixteen inch wheel version can be traumatic and its daft hyvoid primary chain causes some jerkiness at low revs, but if you want the same kind of usefulness that the old Brits delivered without their mechanical horrors, then this is the bolide to go for. £1500 up for the decent stuff.

Generally, it’s a tough engine, up to as much as 75000 miles. The only downside is when thrashing is combined with neglect of oil and filter changes, which can cause the cam lobes to score heavily quite hard to check without taking the cylinder head off. Poorly looked after bikes are easily sussed by the excess of surface rust on the chassis - DR bikes can look like total rats after a mere winter. Also, high milers have rough gearchange actions and the suspension goes loose after 10000 miles. Check the front disc caliper for partial seizure (it squeaks!), the silencers’ undersides for rust and look for minor signs of crash damage.

The GPz500’s engine turns up in a few other models, in detuned form, but doesn’t really work as well in either custom, trail or plain Jane format. The GPz blends the best the mill has to offer in a highly effective package - as at home in the daily commute or on a motorway tour or being thrown through the country lanes.

Where the Honda CB500 scores is in real world riding, its more civilized running and extra low rev torque making it a tad more laid back, but at the same time more precise in its handling without the GPZ’s fast floater of a front 16 inch wheel. Where the Honda loses out is above the ton, when its lack of a fairing and high rev power shows up - totally lacking the GPz’s kick at the ton in top gear.


This makes it relatively easy to chose between these two models. Bear in mind, if buying a newish one, that there are discounters out there who will give 15 to 20% off the absurd retail price of new models. Even bigger discounts are available for the Suzuki GS500E and it’s possible to buy one on the used market for less than a grand which still has plenty of useful life in it.

The GS has some of flightiness of the GPZ’s front end (it seems much looser but doesn’t flip away so violently) and a quite hard revving engine. The only real reason to buy one, other than price, is if you don’t want the complexities of watercooling. The basic design goes back to the GS400, and has been much copied by other manufacturers. The 180 degree crank with a single, gear-driven, balancer emerging as the definitive design for 500cc twins,  whether they be cooled by air or water.


Reliability and finish of the GS500 is very variable, depending mostly on frequency of oil changes and some elbow grease from the owner. Neglect both of these and rat city is reached with inordinate haste. It’s a rare owner who keeps his bike well polished and avoids basic engine maintenance, so overall appearance is as good a guide as anything else. A hard ridden GS500 can be a reasonably fast if enervating buzz.

Yamaha’s unorthodox design philosophy in their TDM850, whether it be 270 or 360 degree cranks, at least adds an element of modernity via its five valves per cylinder head and radically canted forward top end, the latter helping both air flow into the combustion chamber and lowering the centre of gravity.

TDM’s often have naff gearchanges but the engines can run for at least 50000 miles with just a modicum of maintenance; some have gone around the clock without needing a strip down. Valve wear can be a problem on high milers. Some useful tuning kit available, though the easiest way to get more kicks is to fit a loud 2-1 exhaust, which also loses an awful lot of mass.

1996 models re-invented themselves with a 270 degree crank, which means there’s both a bit of torque reaction and primary vibration to quell via .the balancers, though probably less so than having the pistons moving up and down together - it doesn’t compare with the set-up on the GPz500 or CB500, either in smoothness or mechanical efficiency, the TDM engine always giving a slight hint that it’s tearing itself apart.

The reasons for the 270 degree crank are that the power at the back wheel is more controllable and the exhaust sounds more like a Ducati - in theory, anyway! Yamaha even went so far as to dump the excellent Deltabox frame for a messy tubular trellis inspired by the Ducati 900SS... unfortunately the TRX8S0 just ended up looking like someone had thrown disparate components together, although their lack of popularity meant deep discounts for new ones. Some specials builders have managed to produce 350lb bikes based on the TDM engine, which is basically what Yamaha should’ve strived for; there’s an awful lot of junk that can be dumped, not least the god-awful half fairing.

TDM prices go down to £2500 for reasonable if old bikes. It’s also possible to buy a cheap XTZ750, dump all the ridiculous trail gear and emerge with a cheap and cheerful road bike that has a strong and gutsy engine at its heart. There’s a marvellous piece of engineering trying to get out of these big twins but one that needs to revert to the 180 degree crank and wet-sump design that has been so well proven elsewhere.

Any other kind of design applied to the vertical twin produces too much vibration which needs excessive balancers to counter. The 180 degree crank, with its pistons moving up and down alternatively has perfect primary vibration but a torque reaction along the length of its crank, which is easily dealt with by a single, gear-driven, balancer. Of course, the resulting exhaust note is somewhat offbeat but use of a 2-1 gives such an engine a lovely gurgle.

There are an awful lot of machines that have varied from the above concept, much to their cost. The purest vertical twin solution is the 180 degree crank without a balancer. Honda used this in the sixties, making merry with the CB450, amongst others. Both Kawasaki and Yamaha have tried the design in later models, with mixed success.

The British stuck resolutely to the 360 degree crank, essentially two singles side by side with massive consequent primary vibration. Their weak, two bearing, crankshaft would probably have exploded if subjected to the longitudinal torque reaction of the 180 degree crank design - the puny main bearings would’ve been rejected by the Japanese for use in their 250’s. The total failure of the British industry is down to their inability to deal with the vibration, which rose to alarming levels when capacities and power were increased.

There were two options favoured by the Japanese when dealing with the vibration from 360 degree crank designs. The first, as exemplified by Yamaha in their XS650, was to build in mass to absorb the buzzing. High build quality of the motor also helped, along with its low state of tune, making it one of the toughest engines in the world. However, making a vertical twin as heavy as a four and slower than an old British twin isn’t exactly a recipe for success, the engine ending up in a custom chassis of massive mass and odd handling.

The original XS-2 (there was an XS-1 but it was never officially imported into the UK) managed to combine excess mass with nasty steering geometry, especially when compared to the British twins from which it got its inspiration. Whilst the motor wasn’t the most exciting in the world, the rider was ever aware that the thing could go into a high speed wobble that would have them fighting the tarmac within moments.

Upgrading the suspension (with stuff off old British twins) helped but never entirely cured the beastliness. No problem, though, if you never break through the speed limits. Curiously, XS-2’s sell at a premium to later models; therefore best avoided.

The XS-2 was replaced by the XS650. The chassis was given a thorough going over (which added some mass) and the motor neutered. First impressions are of a nicely secure ride but given a combination of bad conditions the speed wobble comes back. People will deny this, but do 95mph on a rough road with some luggage on the back and see if you survive it. Be


The XS650 was relatively well sorted compared to its custom siblings, which really weren’t much use above 75mph. The only reason to buy one of these big twins is the engine’s toughness. An incredible bit of OHC engineering that will take wanton neglect and come back for more. Engines that rattle loudly need the valves doing but still run OK!

There’s also an 840cc kit which causes enough vibration to crack up the pavement on which the bike is perched but doesn’t necessarily cause the engine to explode — it’s that tough. Well sorted engines can liberate 65 to 70 horses, making it rather more fun than stock.


£1500 is the going rate for a decent XS650. It’s one of those bikes where there’s a huge variation in general condition that isn’t reflected in the price. Some have been clocked and have piston ring problems but generally chassis rot is more of a concern than engine viability. The nicest ones I’ve seen are grey imports in Halco’s who specialize in XS650’s, the rough ones tend to turn up in importers who are also breakers.

Rough bikes will have naff calipers, rotten exhausts, ruined suspension and marginal electrics. It really does pay to look around for the best deal rather than accept the first bike on offer. A lot run non-standard chassis parts, some of it good, some of it horrible.

The other route to curbing vibration was to fight it with two balancer shafts, usually chain driven, an excess of engineering madness that was exemplified by the Kawasaki Z750, though also blighted the Yamaha TX750, not to mention the Superdream range and Kawasaki’s Z400/440, though the latter were not so unreasonable designs as the lack of cubes meant vibration absorption never had to reach silly heights.

None of these designs are really recommended, as time tends to magnify their flaws - once a bit of wear gets into the balancers’ chains, vibration increases to British bike levels and fuel economy becomes terrible. Basically, the mass and frictional losses remove all the virtues inherent in the vertical twin design.

Having said that, both the Z440 and Z750 are useful hacks, that will plod along for 50000 miles on the back of their torque.. Never doing anything to excess but always working reliably enough to endear themselves to people who no longer view speed as their god. They are also cheap, around £500 for something useful, although really immaculate import Z440’s from the States fetch over a grand - not bad buys as long as the mileage’s genuinely low, as the motor was well sorted (unlike the Z400 which had a finicky top end and pistons in early incarnations)

Superdreams are another bag of nails. Quite literally rotting away beneath their riders once past 50000 miles, occasionally at half that mileage. Many owners have dumped the whole mess of the balancer system, finding that vibes are no worse after some wear gets into the system. This is shit engineering, that doesn’t sit well on the used market as a seemingly fine bike can go completely rotten within a week or two. It’s not sensible to pay more than a couple of hundred quid for one unless you’re sure it’s genuinely low mileage and well loved. Ride a few to get a feel for the good ones.

The CB400N is actually a marginally useful device in terms of performance, topping out at 110mph and staying on the road with reasonable fidelity. Many an owner got a perfectly decent 25000 miles of use out of them. The 250 version doesn’t develop enough power to really shift its mass and the single front disc is marginal even when not half seized up. Hack country, only buy if cheap. The custom version has little going for it save the fact that it tends to have an easier life and therefore lasts a bit longer before going into total rot mode.

The CB350S took over from the Superdream, sporting a bright red wraparound frame and a modicum of style in contrast to the older bikes. Engines ran reliably for the first 30000 miles, or so, then did the usual Superdream trick of wearing out fast. More so in this case as the majority of them were harshly thrashed, quite a few dying an early death over the DR circuit.

Chassis life was the usual mixed bag of seizing calipers (even the odd disc exploding when it wore very thin), naff chassis bearings and a general ease of corrosion that would have made the bike a laughing stock compared to fifties’ British twins. Not a bad bike to ride, by any means, but one that doesn’t age very well. About £750 for something with a bit of life left and a dull rather than rusty chassis. As little as £250 for the real rats.

Presumably because the Japanese market sensibly had no interest in such designs, Honda sourced their CB450D from the third world where quality standards are often doubtful. For a nineties’ machine the bike had little going for it other than an adequate turn of speed. Build quality was at best questionable but usually OK for the first couple of years; absolutely no reason to pay more than a grand for even a low miler.

Contrast the cheap and nasty design of the Superdream with Honda’s earlier efforts in the sixties. A whole host of vertical twins, from 125 to 450cc. The CB450 being by far the most useful, having over 40 horses; loads of blood and guts. The engine needs to be warmed up gently so that the oil has a chance to circulate to the cylinder head and the gearchange is an acquired art, but the big vertical twin’s always gusty, still able to cruise along at 90mph without exploding.


The CB450 combined a 180 degree crankshaft with a unique cylinder head design - torsion bars replaced the normal valve springs, working through rockers; the DOHC’s themselves acted on another set of rockers, which sat on eccentric shafts for ease of valve clearance adjustment. This required a rare degree of engineering precision in the sixties, so much so that each set of valvegear components had to be matched; mess them up and you’ ll end up with a crankcase full of bits!

The whole point of the exercise was to remove valve float at high revs, although it was soon rendered pointless by advances in valve spring technology. The CB450 engine can be safely spun to 10000 revs, even twelve grand doesn’t cause it to explode although by then power has done a runner.


Because the engine lacks any balancers, the torque reaction thrums away a little at low revs, but come six grand the power flows in hard and the mill smooths out. 90mph cruising is relatively relaxed! Don’t be put off by rough running examples, that’s all part of the package but look instead for the power punch at six grand and check the engine breather for signs of smoke.

Ultimately, the engine goes down from ruined small-ends, which are part of the con-rod material, which in turn can’t be removed unless the crankshaft, with its four massive roller bearings, is pressed apart. A seriously expensive job. The best deals are early seventies models which turn up as grey imports from the States at £1000 to £1500.

It would be easy to confuse the CB500T with the 450. Basically, the engines are identical except for a longer stroke on the bigger bike. Alas, somewhere along the line something went very wrong with the engineering quality of the 500, having displayed piston, bore, valve and even crankshaft problems at low mileages.

Anything that has survived is probably well sorted (a bit more blood and guts can be extracted by using CB450 cams). Minor suspension upgrades sorts most of the handling horrors and a 2-1 exhaust does wonders for the appearance as the “classic” shape has aged quite well. A very useful hack at £500 to £750 but don’t take them too seriously.



The same scepticism should be applied to other Honda twins of the period - CB360, CJ360, etc. They lack the quality of Honda’s sixties designs, should only be considered as cheap and cheerful hacks. The sixties twins - 250/325 Dreams and a host of smaller stuff - are all too old to be of serious use; when they are genuinely immaculate they are also considered classics and therefore expensive.

A bike which can trace its roots right back to these old Hondas is the Kawasaki GPz305. This is as plain and simple as vertical twin engineering gets, with resulting excellent performance, economy and handling. Alas, the engine shared early Honda twins penchant for not getting sufficient oil to the cylinder head when warming up and also had disturbing crankshaft problems.

Engine life is highly variable. Some owners sing their praises to great heights, others curse them violently. As far as buying a used one goes, the main problem is that the engine can go from seemingly fine to a bag of nails in a very short period of time. A lot of luck’s involved in finding a good one that will last well.

The chassis is built down to a price, corrodes nastily over our winters with the usual naff calipers, disintegrating exhaust and rattling chassis bearings. Loads of spares in breakers, so not that expensive to fix. In 1996, its last year of manufacture, there were some deep discounts on new ones, as little as £2500. There’s no reason to pay more than £1500 for recent stuff and it’s possible to buy a hack for less than 500 sovs.

Another bike with generally splendid performance but a potentially expensive engine’s the XS500. This combined an 180 degree crank with a chain driven balancer, which when all was set to perfection provided good power, reasonable economy and vastly superior handling to the XS650, which was sold at the same time.

The price paid for the relative complexity, which included DOHC’s and eight valves, was an engine that could die, especially when thrashed, without much warning. Age isn’t kind to them, either, with alloy rot turning minor operations into major traumas - corroded in screws, for instance, tend to snap off or tear the threads out of the engine. Even changing a spark plug can result in having to rip the head off to do a helicoil. And the XS500 is one of those engines that never runs happily once it’s been disturbed. Spares are also rare on the secondhand circuit, any potential engine failure turning out expensive.

The chassis, though, is a good one, based on Yamaha’s racing experience with its RD strokers and worth reinventing by fitting a motor from a different model. Some dealers try to off-load XS500’s for as much as £1500 but given the engine troubles paying more than £500 is plain silly.

There’s a huge range of vertical twins out there. Everything from 125cc hacks to prime meat TDM850’s. The whole reason for going for a Vertical twin is its relative simplicity. When it gets too complex it loses its reason for existence. Because so little development of the breed has taken place (even our esteemed editor has worked out two ways to eliminate their vibration without loss of power or efficiency...) the whole market’s still wide open.

The choice of best buys depends on what you want. For laid back riding go for a grey import XS650; just don’t expect too much speed. For good overall performance chose a GPz500; if you can afford it go for the later 17 inch wheel version as it’s much less likely to throw you down the road. For real practicality together with some blood and guts, chose an early seventies CB450, again on the grey import circuit. If you want to keep the replicas in sight and don’t mind doing a little work to its chassis, then the TDM850’s the only game in town.

Dick Lewis





Sunday 17 May 2020

Triumph 650 Thunderbird



There she stood in all her glory. Chrome, alloy and paint gleamed. Bolts were wired in. Rocker covers had little springs between them. Lots of neat little detail points. The exhaust blared beautifully. The whole chassis went into a vibratory dance on its stand. Wanted to skip across the ground. Hmmm! They're all like that, thought I, especially the big 650’s.

I was down £3500, had bought the bike on a whim! What happened was that I'd gone to the BMF rally and ended up talking to a group of Brit bike enthusiasts. I was on my well renovated Honda CB400F, which could, in some ways, be considered an honorary Brit - being mild and pleasant, in no way excessive. The owner of the Thunderbird was a giant of a man who let drop that he was on the track of a Vincent and might want to sell the Triumph quickly. We swapped phone numbers. The day before he called I’d been offered £1500 for the Honda. Fate was obviously telling me something.

My first day’s ride went something like this. A few moments of panic when the compression did a runner and I seemed to be kicking the engine over as if the clutch was pulled in! Then she caught, though the compression suddenly coming in nearly broke my right leg. There’s an acquired art to kicking over old Brits and a moment of inattention can lead to a broken ankle or even leg if the engine suddenly kicks backs!

Nearly broke my left hand pulling in the clutch lever. Thought, wimp, I'll soon firm up my muscles but it was always a pain in town when the unit would overheat a little. Bring in some drag, make the bike difficult to control at low speeds or a standstill. The oil would also seize up the plates overnight, making it mandatory to turn the engine over on the kickstart a couple of times with the clutch pulled in before trying to start the motor. The non-standard Amal carb had a cute little button that was depressed to prime it with petrol, which would cascade out. Tickling the carb was quite reassuring as at least | knew that the petrol was getting through. With the carb tickled there was no need to use the choke on even the coldest day.

On a good day she'd fire up first kick, on a bad one she’d take ten or more exhausting kicks. One aspect I certainly didn't like was that when the engine stalled when hot it would sometimes sulk for five to ten minutes before starting again. You can imagine how angry this made cagers if they couldn't swerve around the bike or knock me off!

Out on the road for the first time. Feel that meaty torque, made the Honda four seem very wimpy indeed. It was fairly brutal with hardly any sophistication in the way it took up the power. Almost as if the bike wanted to get going with indecent haste. Once the clutch lever was past a certain point it jumped viciously forward.

Try to engage second gear only to find the thing locked into neutral. A real struggle with the gear lever as it’s on the wrong side compared with my normal Jap iron and needs enough pressure to rip my leather shoes apart. Pull over, only to find that the forks are jerked viciously to the right. Did | bring my heart tablets?

Back into first, an almighty boot and she went into second and then third. Triumphs are supposed to have slick gearboxes but this one had a distinctly vintage feel, was almost as bad as that fitted to a BMW R60 that once passed through my hands - at the time I couldn't believe that a supposedly sophisticated bike could be so agricultural but experiences with other old style BMW boxers just confirmed my initial impression.

When I tried to rev through the 6000rpm mark the engine went into a series of stutters. Slicked into fourth gear, tried again, but no hope of getting through that barrier, though in second or first it'd bound up to 8000 revs without much restraint. In fact, I had to stop myself from winding on the throttle too rapidly. Most people would as only those who don't mind their eyeballs falling out and all extremities getting a strenuous vibro-massage would persevere with thrashing a 36 year old engine. The sheer age of the machine puts most complaints about it into perspective and there’s no real way of knowing what previous owners had done to the poor old thing.

The basic feel of the Thunderbird was exactly what you'd expect from an early sixties motorcycle - rough and ready with every aspect of the machine, feedback from the road as well as vibes, hitting the rider like a slam in the teeth from a baseball bat. It made the Honda, which in relation to modern Jap fours is distinctly out of the game, appear a paragon of advanced engineering with the smoothness of a turbine and ease of use of a TV.

After a fifty mile blast down the local country lanes I returned home as if I'd done a twelve hour day of hard labour. Although light by modern standards, at well under 400lbs, it was quite heavy going when steered through the bends at a reasonable pace. The big front wheel on thin rubber was most probably the culprit. It was an amount of effort that diminished as I became used to the Triumph. Only noticing it when leaping aboard modern bikes and finding that the same kind of input had us all over the shop like an accident looking for somewhere to happen.

I was going to sneak back indoors when I noticed that the pre-unit engine was leaking oil. The return oil pipe was waving around like a small snake about to strike - the residual energy from all the vibes had given it a case of the shakes. Then I saw that two rocker caps had gone AWOL, despite the spring that was supposed to stop them unfurling. Various nuts had disappeared off the chassis. And the rear light assembly had disappeared completely - apart from the ignition the electrics were completely dead as a couple of wires had shorted out and blown the fuse. Not that the front light or horn were up to much, being original Prince of Darkness fare.

Cry? Too true. Trouble was I couldn't mouth off to the nearest and dearest as she was still sulking about the amount of dosh I'd blown. I had to pretend that all was sublime. New rocker caps, loads of Loctite and all the screws and nuts gone over, I thought I had the bike sussed...

The electrics were another country, with a couple of years worth of bodging. The whole lot in desperate need of an upgrade. I ended up with Boyer ignition, 12V conversion, modern rectifier/ regulator and a complete rewire. Not to mention new lights all round.

Even this great effort still left the bike in a potentially weak state because there was just so much vibration coming off the engine that few relatively fragile electrical components were able to survive. The electronic ignition being the exception - it definitely aided starting. Never more than three kicks needed from cold and hot starting was instantaneous. Hurray for some good news.

The next time I went for a ride the bike didn’t want to go beyond 5000 revs in any gear. As this coincided with minimising the buzzing it wasn't that bad. There was plenty of torque, though it was at those revs that there was a sudden torrent of power. Whilst. riding around I pondered if it were the carbs, electrics or mechanics that were giving the trouble. What I needed was a Triumph expert.

Before I could find one I experienced my first ever speed wobble. I've known many Jap bikes that were vague, weaved and wallowed a bit, but the way the Triumph went down was entirely different. As the handlebars hammered from lock to lock, and the Thunderbird skittered from one side of the road to the other, the whole tubular frame gave every impression of being transmuted into rubber or plastic.

Neither wheel wanted to go in the same direction of what was left of the frame. The violence of the wobble was such that I couldn't even see straight, let alone form a coherent thought. My mind was filled with fear and dread that these might well be my last moments alive. What a way to go. Though in retrospect I suppose there are a lot worse ways to die - it’s just that I didn’t think like that at the time.

I wrestled with the handlebars - bars, incidentally, that were fashioned perfectly to accommodate the human body in more normal circumstances - the oscillations amplified further, giving every impression that the forks were going to snap off at the headstock and I was going to end up scraping along the tarmac on my knees at 70mph. Just the thought of it makes me want to throw up, let alone the nasty reality.

For a little while | just sat there, hoping for divine intervention. In the more sane moments, I was able to realise that there was an actual limitation to the size of the oscillation, which luckily coincided with the width of the road! Just as well it was a deserted country lane without any predatory cagers hanging around, though they might well have dropped a load at the fantastical sight of the Triumph and its cringing rider.

From some recess of my mind I recalled the solution to my near death experience. Remembered that the worst thing you could do was try to fight the wobble as that only resulted in it increasing in amplitude. God knows where that nugget of information came from. I eased my grip on the bars and gently rolled the throttle back.

Initially, I thought I mucked things up in a big way as the old heap gave an almighty, desperate shrug, just like some big old horse refusing to do a jump and trying to throw its rider right out of the saddle with a mixture of pleasure and violence, but then it went back to its previous antics. As speed decreased to 50mph the bike snapped out of its suicidal instincts and quietened down again. Almost as if a miracle had been performed and, magically, I was suddenly aboard a completely different machine that actually had some metal in its frame and wheels that pointed in the same direction.

I pulled over. I was in a right state - weak of leg and not far off bursting into tears, if only of relief. It was like being on solid ground after years at sea. When I stopped shaking, I kicked the wheels, had a fight with the forks and swinging arm, but could find no incipient looseness. I bravely resumed mv ride. thinking of that song, gone wild in the country.

Handling was, anyway, a rather weird mixture. Suspension was so taut that it could take a couple of sumo wrestlers and only reacted to the deeper pot-holes. The tautness went along with the lack of travel, three inches maximum. But it was never precise, the front end wavering a little as speed increased and the back end feeling a bit hinged-in-the-middle when the bike was snapped through a couple of bends. This era of Triumph could not compete with rival Nortons in the bends but had a better reputation for their engine toughness (although: this was relative and somewhat laughable in comparison to modern bikes).

With all its mystique I was expecting something special but in reality it couldn't really keep up with a mediocre Jap middleweight, like a Suzuki GS450E! Back to the engine problem. I needed something to take my mind off the handling and even an excuse to avoid riding the bastard. I couldn't find anything wrong with the carburation and electrics, began to suspect that there was a serious malady with the motor.

I took the cylinder head off. This was when | became really depressed. The head had two large cracks running through it. It was the old, weak eight stud job rather than the tougher, later nine stud item. At least the valves looked OK and the guides weren't leaping up and down, as they have a tendency to do.

I eased the cylinder off, suspecting the worst. The piston skirts were a bit scored but still useable. It was the big-ends that got to me, loose being an understatement. The 1961 model had a pre-unit engine which meant it was at least easy to whip the whole motor out. Except that the gearbox was never slick like a Triumph should be and that the chain primary chain was so worn that large grooves were scored in the chaincase.

I'd been done! The annoying thing was that the motor ran well enough, initially, to convince me that it was a good ’un. As it was a private deal there was no easy way to get my money back. The oddest thing was that it was the very toughness of the motor, its ability to run seemingly fine when in a desperate state, which had caught me out. Probably the only way of sussing such a mill is to have an intimate knowledge of the amount of vibration a good motor puts out. Which is much easier said than done if you're coming back to British bikes after a long absence.

There followed a few months of wandering around autojumbles, bargaining down the silly prices demanded for various engine parts. The major expense was a rebuilt crankshaft which I had dynamically balanced. Putting together an engine with bits from different sources, with varying states of wear, is a recipe for disaster. But the Triumph came together easily enough and the distinct lack of frenzied vibration convinced me that I'd finally assembled a good motor.

Whilst the engine work was going on I'd fitted new steering head and swinging arm bearings, new brake shoes and also rebuilt the gearbox with used parts, finished off with a new primary chain. The overall cost was in the region of four hundred notes; not bad by modern standards but appalling given the amount of dosh the bike had cost.

The final machine was transformed. Rewed happily up to 8500 revs in all gears, which now slickly engaged. Vibration was only heavy going above 6000rpm. Handling was still on the vague side but it never went into a speed wobble, even when pushed up to 115mph on the clock. Fuel was a reasonable 55mpg. Comfort was close to excellent (once used to the buzzing). Braking was marginal at best, often slamming the throttle shut was more effective than using the drum brakes!

I did about 8000 miles on the bike in this state. Then it started to go off again! | wasn't going through all that hassle again, so I sold it for £2900. A loss, for sure, but the peace of mind gained was well worth it!

John Trent

Suzuki GS750



The wheelie came with a large detonation. The clutch definitely didn't like being dropped at 7500 revs! The front wheel rose off the ground, the bars waggling in my hands and obscuring forward vision. When I ran out of acceleration in first gear - at maximum revs the 750 four became rather vibratory - the front bounced back down, as if confirming the utter reluctance of the bike to indulge in wheelie madness.

My view of the road revealed a rapidly encroaching van. I'd somehow wandered on to the wrong side of the road. It didn’t take much thought to work out that the van would survive a head-on collision rather better than the Suzuki. Well made they might be but not that well made! I twitched the reluctant bars and just managed to twist past the van. Some steroid abuser skinhead stuck his head out of the window and shouted 'plonker' at me at the top of his voice. Charming!

This all happened on my first day of ownership of the 1978 machine. 16 years of abuse and 26000 miles hadn't really dented the GS750's sheen or ruggedness. Mostly because it was the fabled one owner, who was much more mature than mad. At £1500 (in 1994) it was a pretty good buy in my book. Additions to the stock bike were a set of Koni shocks, slinky saddle, plastic guards, full chain enclosure and stainless steel exhaust. It was one of those bikes that had been much lavished with tender loving care.

God knows what the poor thing thought about falling into my hands. After finding out that wheelies were not much cop, I threw in a bit of speed testing on the M4. The M4’s heavily policed in the Welsh half but as I hadn't registered the bike in my name and didn’t expect to stop for the cops it wasn't a big problem, was it?

The gearbox didn't like to engage fourth under a heavy throttle, making a stutter in the forward acceleration. The GS didn't want to do much more than 110mph under these circumstances. When I eventually wound it up successfully through the gearbox, the bike shot up to 120mph on the clock. It took a long time to pass 130mph and by the time 135mph was on the clock the poor old engine was trying to buzz its way out of the tubular frame.

The handling was something else. On a long, smooth straight the thing was weaving over a full lane’s width of road by the time 100mph was on the clock. Almost certainly down to inadequate swinging arm bearing support there was 500lbs of machine to fight against. When I went to swing the beast through a gentle curve at 120mph it was all over the shop and came out of the bend at 130mph with some strong handlebar shakes.

Later, I did find that it had one safety feature. If I wanted to tame the weaves in a curve - which basically meant getting the speed below 90mph when it was a whole different, much improved, bundle of metal - all I had to do was gently close the throttle a little, which had the added benefit of tightening up the bike’s line in the bend.

Conversely, if not perversely, trying to lose speed using the front brake, which had been upgraded with Goodridge hose and EBC pads (and was therefore pretty good), made the bike buck like a good ’un and try to run off the road. Even the rear brake had an unsettling effect on the GS when leant over and it was a big brute to duck and dive with when some unexpected obstacle turned up. I quickly concluded that the bike was only just in control of itself and didn't, later, find anything to make me change that conclusion.

On the good side, the 120 mile ride home turned up no pains. The non-standard saddle was luxury personified and the riding position sporty without being excruciating. An excellent compromise that rarely turns up in modern bikes. Further adventures revealed that the only limit on a 500 mile day was a bit of tingling in my extremities, easily avoided by riding in the 75 to 90mph range in top gear.

The only real limitations to serious touring were that its naked nature meant I got cold and wet, and also that luggage was limited to what I could bung in a tank bag, as it didn’t like too much weight out back; wasn't even happy with the presence of a fairly light pillion. The Konis might’ve been slightly under spec or it might just be poor weight distribution. It wasn't that much of a downer as I normally ride light and solo.

It's a heavy handling bike unless you're into steroids but one that becomes less wearying as you get used to it. Its width is hard going in traffic, I tended to end up winding the throttle up until a cage moved out of the way the exhaust made a delightful howl at 7000 revs that drove both pedestrians and dogs completely wild. Wear boots as dogs have a strong inclination to take nips out of GS750 riders’ legs.

After three months the bike and I had settled into each others ways. I’d become a bit more moderate on the throttle as there didn’t seem anything to be gained from bouncing the valves through the gears - other than the antisocial exhaust howl!

Maintenance wasn't too nasty. Change the oil every 1500 miles! Electronic ignition plus valves and carbs that had settled in nicely and didn’t need any attention, meant it was an easy life. The full chain enclosure meant that chain adjustments were rare - the GS series have a bit of a reputation for tearing through chain and sprocket sets in around 5000 miles, so a full chain enclosure is well worth having.

The well built DOHC four cylinder engine made all of 70 horses. Not exactly state of the art but the relative mildness meant it was more or less bullet-proof. The one weak spot was the alternator, along with the rectifier/regulator; either or both could burn out with little warning. Mine was running a Superdream rectifier/regulator and had been rewired (| don’t know if the alternator was rewound or not) and it all seemed to work well.

Don't try running a stronger headlamp or adding any heavy duty accessories (like handlebar warmers), at the best the electrics are marginal. The front light was up to 50mph cruising down unlit country lanes, but it wasn’t the kind of beam I'd like to suffer for long on unlit roads.

On one occasion I was hurtling along when I spied a black shape in the murky glow of the light. I only realised it was a dead dog after the front wheel had run over it (it was dead by the time the GS finished with it, anyway)... the bars twitched a couple of times but the sheer, excessive momentum of the Suzuki carried us forward.

In a year I did 13000 miles without any real problems. Didn't even fall off or hit anything - a minor miracle given the way I like to ride - though there were a couple of near misses. The excess of the GS tended to make the more nervous cager twitch out of the way. Even the cops looked on the machine in a generally benign way.

The bike qualified for classic insurance (about £90 for TPF&F), fuel was around 40mpg and it needed two sets of tyres as it went all weird when the tread was down to 3mm - not the kind of machine to run on bald rubber. No way! The front pads were another heavy wearing item at around 4500 miles a set - not that surprising as the bike often needed to be pulled up heavily for the bends as an alternative to falling off.

The engine’s good for at least 50000 miles, often twice that or more. The clutch and valves are the main faults on high milers, both easily checked. The clutch may rattle at tickover but it should go away when the throttle’s twitched. The electrics are nasty. The chassis is strong but prone to rust, and the suspension needs to be upgraded.

You can buy a rat for less than £1000 but it'll need a lot of work. Better to pay £1500 to £2000 for something sound with sensible mods (make sure the engine’s stock, though). I sold mine for £1750.

Dave Harris

Saturday 16 May 2020

Norton 850 Commando



Oh for a good British motorcycle, thought I once in a blue moon. I’d been there, done that... on Triumphs, BSAs and Nortons. Gone on to a series of fearsomely fast Japanese fours. But, yet, I still found myself occasionally lusting after some British relic. The UMG reckoned a lot were renovated, revitalized and re-engineered, to quote an unusual amount of enthusiasm. Could it be true, or was it just another media ploy to sell copies? I had to find out.

The classic glossies provided an excess of dealers for me to visit and even some private ads for me to follow up. I even cajoled some tests rides. A Triumph 750 was a rolling massage table, a BSA Spitfire shed parts at an incredible rate and by the time I tried a Norton 850 I was ready to be amazed by its Isolastic absorbed lack of vibration. Hey, I’ll have one of these. Not unless you've got five grand to burn, said the dealer.

Apart from the lack of vibes, I was well taken with the surly torque and stable handling. The bike had the vernier shim conversion which made setting up the Isolastics, so that they both absorbed vibes and held the bike together, relatively easy (as the swinging arm was only connected to the frame via the Isolastic mounts). Oh, yes, it also looked perfect in its classic shape. I had to have one.

The only cheap ones were in a disgusting state. By cheap I mean under 2000 notes. I persevered, being somewhat annoyed with the amount of lies people told over the phone. Eventually, for £3500 I found a 67000 miler, slightly shabby chassis (but with the vernier shims) and a rebuilt engine. I knew it was a good one from the way it came to life first kick, powered us up to 120mph at a rate that would shame many a Jap four, and from the lack of vibes or oil leaks. The owner had kept the bike for ten years, was only selling because the wife had dropped her fifth brat and a Transit van beckoned.

I figured I could do a respray myself and soon have it shining with all the glory of a true Brit. The bike was basically a Mk.3 but with the odd chassis bit off earlier models. Definitely not concours, more your well lived in, cleverly updated and generally sorted piece of tackle. I sprayed her silver grey, polished the alloy, filled the tank, primary drive and gearbox with fresh oil, then headed for the open road.

Around Lancaster way there are plenty of fast back roads, which were taken with aplomb by the charging, snorting Commando. Though in its lack of vibration it was relatively civilised it was still a beast at heart, a raw and raunchy 850cc vertical twin. Masses of torque thrust the relatively light and narrow chassis forwards in a most rewarding and exhilarating manner. It's also one of the few British twins that will reliably canter along at 90 to 100mph, without a deluge of vibration and the old bits falling off routine. In its day, the engine had a reputation for blowing up in a big way when tuned or hard used, but using the later engine parts lovingly assembled removed most of the horrors inherent in an engine that could trace its roots back to a mild old 500cc twin.

So impressive was its general performance and usability that a few Jap replica riders were won over by its brutality. It couldn’t do 160mph but it could get up to 120mph in a relentless and charming way that held the unwary and innocent rider all agog. Wonder was even expressed that the British bike industry went so easily down the toilet. Two friends ended up trading in for Commandos. This unlikely trio was given pause for thought when one of their number (unfortunately, this writer) suddenly found his machine rattling furiously around the top end and smoking away like a 30 year old MZ 150. Surprise was expressed that it didn’t have a camchain tensioner as it sounded just like a CB750F1 at death’s door I once owned.

The noise was coming from a loose exhaust valve guide that was merrily popping up and down in the head. Having removed the cylinder head it seemed like the decent thing to do - to gas-flow it, upgrade the valves and their seats so unleaded could be used as well as adding new valve guides. I did most of the work myself, total cost coming out at £120. The bores and pistons looked just fine, were left well alone.

Unfortunately, the engine pinked disarmingly on unleaded due to the high compression pistons fitted, so the new valves were a complete waste of dosh. Valve guides are something of a weak spot in Commando top ends, can go without much warning. With the gas-flowed head, economy improved from 45 to 50mpg, although performance didn’t increase to any discernible degree - no doubt the poor aerodynamics of a naked machine overwhelming any small amount of extra power that might turn up.

One of my mates engine’s blew up in a big way, as in the con-rod poking out of the crankcase. Turned out he was regularly revelling in taking the engine to nine grand! This is a quick way to reduce a Commando engine to a molten mess however much it has been upgraded or re-engineered. He was led away in tears after this had gently been explained to him. As noted, these machines do indeed get to you.

My motor ran for another 14000 miles, or so, before performance went awry and starting became awkward - not something you want to experience on an engine that needs a real manly kick. I was tempted to blame the electronic ignition, always on the lookout for an easy escape, but, no, a local expert in these matters reckoned on worn out bores. Quite literally as they were already on maximum oversize. A few phone calls to a couple of Norton spares dealers secured replacements plus brand new pistons and rings.

Even after such a low mileage both the valves and the guides were also showing signs of serious wear, so another round of replacements. The crankshaft felt secure on its Superblend bearings but the primary chain and clutch were both well knackered. When it was all sorted out, I’d spent over £450! Meanwhile, my other Commando riding friend had sold his machine at a nice profit, having done 21000 miles with nothing more irritating than regular 500 mile services. But he could tell which way the wind was blowing, realised it was only a matter of time before something nasty went down.

I suppose it depends on how seriously you want to take things. If you’re just after the odd Sunday afternoon outing, the bike will probably last for years but if you’re into heavy riding at reasonable speeds then it can be very quick wearing. Money’s saved on the consumables - I found it very hard to wear out a set of Avons or the cheap and cheerful drive chain, whilst the rather primitive front disc made up for its basic nature by never coming close to wearing out the pads in 18000 miles but that included some hairy moments in the wet.

Not that any of this will stop the true enthusiasts singing loudly their praises because they have a certain character coupled with a great deal of practicality that makes them rather unique in the old British bike game.

A.M.R.


Friday 15 May 2020

Honda H100S



All kind of things went through my mind when I slung a leg over an H100S for the first time. In a school car park on a Saturday morning. The instructor had gone through a complex set of commands that had left me sweating. The bike felt both very small and very dangerous at the same time. I found the throttle and gave it a twist. Nearly popped my eardrums and the instructor shook his fist at me!

Was it up or down on the gearchange? How much throttle should I use? I managed to work out the front brake and clutch levers, the former reassuring. Gear, throttle, clutch... motor stalls dead! How to reduce a 32 year old man to a gibbering wreck. A few more tries, I finally hopped forward like a belligerent kangaroo right into the path of the instructor who was hurrying over to find out why I was the only one not in motion.

Judging by his expression, as he leapt out of the way, I’d been written off as the village idiot. However, an hour later I had a pretty good idea about clutch, throttle and gearchange coordination, could waltz through the bollards almost as well as the seventeen year old kids. At least 15 years in a cage meant I had plenty of road sense...

One's perspective from the saddle of a motorcycle is entirely different to that from the seat of a car. Roads that were previously benign turned into an obstacle course of bumps, potholes and wavering cages that didn’t seem to have a clue. I was soon cursing them like a dedicated biker. It quickly became evident that I had to learn the survival path through this chaos, but it wasn’t something that could be learnt in an afternoon, a week or even a month. It actually makes much more sense to move from a bicycle to a motorcycle rather than from a car. But I persevered.

Buying a six year old H100S off a neighbour was my next move. The guy was a bit notorious for selling stuff that was just about to break down but I had a mechanic friend look the 19000 mile machine over and he said all was OK. So I wasn't going to argue with him.

It all seemed very nice to me if a little terrifying when wound up to its top whack of 70mph. The main use of the bike was a five mile commute back and forth to work every day, but I soon found myself leaping on the little Honda just for the fun of it! The nearest and dearest went into full interrogation mode every time I disappeared for a few hours after telling her I was going to do a half hour run to get some practice in. The bike was rapidly becoming addictive.

Part of this was down to living out in the countryside, a wide selection of back lanes to throw the H100 through. It was summer, hot and sweaty, and a motorcycle was art ideal way to bop around of an evening. There were a wide selection of pubs to visit, many of them full of fifteen, sixteen year old girls wearing not a lot. I cursed the learner plates! But there you go.

One area where the Honda was literally in the Dark Ages was the front light. Bloody hell, the first time I rode in the dark I thought it was on pilot rather than main beam. There’s naivety for you! The long summer nights and the wife’s whining meant I usually came back before nightfall.

I don’t know if it was me or the bike, but once the engine was warmed up the gearchange was like slicing through mud, full of false neutrals and even slipping out of gear when I thought I'd engaged it! It was then I found out that there was a separate oil supply for the gearbox, so |Ichanged this but it only had a minor effect on the box’s slickness. It was quite embarrassing to find the engine screaming plaintively whilst I struggled manfully with the gearchange.

Other than that, the H100 soon became pretty easy to rip around on. The last part of my journey consisted of a mile of city work, which in the car usually took longer than the rest of the journey. On the bike, it was a case of barrelling along the gutter and doing the odd twist and turn. I saved about fifteen minutes just on that part of the journey.

The first few weeks I was so cautious that I didn’t come close to having an accident or falling off. It was when I gained some more confidence that I began to have some close shaves. Riding a little bit too fast for my level of experience, as I still had to think about my actions rather than rely on instinctive reactions. After nearly being crushed by a couple of converging cars, I decided to slow down before I was killed or maimed.

You have to be a real mad bugger on a motorcycle to ignore the signs of riding too fast too soon, though back when I was a youth |Ihad a couple of acquaintances who killed themselves on bikes... must be a matter of age making me more of a coward. Experience before age, or something.

After four months, in which I did over 5000 miles, the engine was showing signs of its age. It would coke up in town, needing much throttle work to keep it running. Top speed was down to 60mph and economy went from 85mpg to 50mpg. Decoke said my mechanic mate. He then explained the rather arcane needs of simple strokers. Head and exhaust off. Removal of the former revealed a scored bore and when the cylinder was removed the piston flopped around on its loose small-end bearing.

The mechanic friend reckoned it was shagged beyond help! I cursed my neighbour but was relieved to find the solution was an engine from a breaker for £225. It was a simple job to fit, and I was pleased to find that the gearbox was a whole lot slicker though still not perfect.

By then I was well into the motorcycle game, having developed sufficient survival instincts. I was able to string the Honda along on maximum throttle for most of the time. I was ready to take my test and move on to something bigger, before I melted the engine again.

It was ridiculous to be reduced to a bundle of nerves at the age of 32 but that was what happened on the day of the test. I wore my silly fluorescent jacket in the hope that I would be mistaken for a real commuter rather than a wannabe hoodlum. The H100S ran like a dream and I passed!

As it happened, poor finances meant that the H100 ended up as my sole means of transport. So it looks like we are going to be friends for a while longer.

TR.