Wednesday, 15 November 2017

Moto Guzzi 850 Le Mans


Having picked up the bike from South London, my first ride on the 850 Le Mans Mk1 was the journey necessary to get it home to Essex. This involved an immediate dive into the Saturday morning shopping traffic milling about the South Circular Road.
 

Although, fortunately, already used to Guzzis, two things threatened to be something of a problem straight off. One was a very tall first gear which can’t be used properly at less than 30mph, so lots of clutch slip was involved which really tests the old forearm muscles in slow trickling traffic queues. The other is that the snatchy clutch is apparently intended for the specific purpose of aiding gear selection while on the move only, as it has a marked penchant for dragging suddenly without notice. Sitting still with the clutch lever pulled in at traffic lights it can’t understand at all; it keeps trying to go all the time.
 

After not very many minutes into the journey my next discovery was that this wasn't going to be such a problem as might be feared in fact, there were not too many occasions when my forward progress was held up to any great extent. In some magical fashion, great gaps continually opened up in front of me and most other road users appeared to cower to one side.

This had a great deal to do with the threatening aspect of the after-market half race fairing, together with my own businesslike racers crouch brought about by the clip-on bars and home-made dural rearsets. Not forgetting of course, the raucous thunder and crackle of the Lafrancono competition ’silencers' reverberating off every wall. The bike spelled it out very plainly to all and sundry. Get out of my effing way or else.
 

Grinning hugely, I made it to the A2 for the Dartford Tunnel in quite a short time. The high compression, 844cc motor was very flexible. Leaps through the gaps in traffic needed little more than a quick flick of the wrist to excite the accelerator pumps of the extravagant, filter-less, 36mm DellOrtos. The bike showed its disdain at having to shut off with a snarling, spitting overrun, much to the alarm of its next prey, the car immediately in front.
 

It’s been like that more or less ever since. Few car drivers seem to want to tangle with such a crude, loud, horribly aggressive motorcycle. I fitted high powered, dual electric horns, but more often than not they just need a quick test now and again to make sure they still work. Once out in the countryside on the three lane dual carriageway A2, I discovered that at 70mph it's just starting to go properly. At 50mph it feels so slow I could get off and walk The Lafranconis are a bit compromising - there's not enough back pressure below 4000rpm to keep the engine happy, although it still has a bit of power between 3000 and 4000, it’s largely peevish about having to rotate so slowly. Giving it too much of a handful in this rev range achieves little, and only results in a temporary quick tinkle of pinking if the air is very warm.

4000rpm is a magic number. Much more usable power is encountered here, where the motor smooths out dramatically, and pulls strongly up to 5000rpm. At this point there is a rough spot - rocking couple - vibration but beyond it smooths out again with another power step at around 5500rpm, which goes up to peak torque at 6600rpm. After this, peak power is supposed to occur at 7300rpm, but really the peak torque point is the most meaningful.

Beyond that it literally runs out of puff - you can move gas through two 422cc cylinders only so quickly — which is an advantage as it makes it difficult to over rev. I would expect that it’s impossible to drop a valve even if you missed a gear.

Although the gear ratios are quite evenly spaced - making it easy to keep within the power band for any given road speed - as is usual with Guzzis, fifth gear is like an overdrive and so it is quite likely to go no faster in top than it will in fourth. Using fourth is more fun as it enables access to the post 5000rpm part of the rev range (quite apart from the noise — sorry, my ears are still ringing... what?).
The claimed top speed of 130mph coincides approximately with the peak torque point in top, where l am required to get well down behind the fairing if this is to be achieved at all easily. In general, then, the bike is equivalent to a Jap middleweight in. performance. Not terribly inspiring perhaps, but it couldn’t be more different.

I can’t tell you exactly what I've had out of it for the simple reason that the instruments are hopelessly inaccurate, especially at the top of the scale (you know it's going faster but the needle hardly moves). As far as acceleration goes, the motor could probably go much better in this regard without one particular encumbrance. This is the mammoth flywheel, a whopping great lump of steel which also contains the twin plate dry clutch - even with the throttle shut off that flywheel is still tending to hurtle the bike forwards, disconcerting for the first time rider who expects the brakes to stop the Guzzi in a linear manner.
 

The secret is to keep the flywheel spinning at a fair lick, and tap into this energy with a gear ratio selected for a particular purpose. Braking is nearly always accompanied by a change down, for reasons mentioned above, as a reward for a deal of concentration and coordination. The throttle is used to chase the revs up the scale; you can’t whack it open as this gets you nowhere fast. Also, clutchless changes are totally out of the question. If you ever buy a Guzzi, remember everything you have learnt about Jap bikes - and then forget it all.

This particular machine is essentially in a standard state of tune, and so it is somewhat surprising to learn that in its previous life most of its active moments - outside of the garage in which it had been constantly done up and fettled - were spent on a race track. Major mods were the junking of the less than ideal camchain in favour of steel gears, oversize carb jets and an enlarged sump. In addition the engine was painted matt black.

The gearbox was a pleasant surprise, usually quiet and smooth, even slick at times, it wouldn’t even disgrace a Japanese bike. On the rare occasions when I miss a change, it’s because I’ve come to expect rapid changes. Now and again, it does have a little hiccup, just to remind me of its true origins ~ if it’s being particularly lethargic it usually means that it wants an oil change. The fuel consumption is, er, well, adequate. It’s supposed to manage 45mpg, but the trouble here is that I can't leave the throttle alone, it’s just too much fun. Fifty in first, seventy in second, change into top at over the ton, that sort of thing. I usually get the high 30s or 40mpg. Mind you, it's inefficient at slow speeds - my worst ever was 32mpg while touring Cornwall (second gear all the time).
 

The suspension had been well sorted. The amazing thing is it’s all the original stuff too. As with many other things, it looked like everything had been taken apart including the rear shocks - and put back together again just so. A common aftermarket rear shock is maybe Marzocchi or Koni but here, large as life and twice as ugly, are the originals. It’s all a bit on the firm side but I can’t fault it.
 

In fact, the suspension shows up another area. Given a reasonably fast bit of swervery and with the motor nicely on the boil, both it and the suspension are a bit too quick for the long wheelbase and slow steering. It gets to a stage where one has to manhandle it over to get around some of the corner before the road runs out. Can’t have it both ways, I suppose, and as the geometry makes it absolutely rock steady at any speed in a straight line, I think I prefer it that way round to wobble and weave.

In fact, the rear springs are so good the swing arm has to be really whip-lashed by the old shaft drive before any serious lurching takes place, normally a common Guzzi problem. Sure it goes a bit vague if throttled off in a bend, but not with the same terminal feeling I’m normally used to. And although the steering might be a touch on the slow side, it is inspiringly stable and secure. There is a fixed hydraulic damper, which can be slightly recalcitrant in the cold weather when the fluid is stiff, but this is not a problem Normally on this model, the steering damper can be switched in or out of position with a large knob in the centre of the steering head In spite of weighing in at some 430lbs, the Le Mans is manageably low and lean, having lower suspension than other Guzzi models.
 

Getting all of both feet on the floor should be no problem even if you’re less than six foot. The sculpted aftermarket seat with raised pillion section helps here, as well as looking much better than the normal squared back thing. The seat is a bit hard but doesn't compress. Generally, the riding position is just right, and I haven’t had an problems with wrist ache while leaning on the clipons — in fact, it doesn’t feel like you’re leaning at all after a while, rather they're in just the right, logical place. In comparison, my Spada's bars were dreadful. Only slight problem here may be an aching right mitt due to preventing the heavy carb springs slamming the slides shut. Tip: get all four fingers curled around the twist grip as it prevents thumb ache.
 

Whether such a bike should qualify for having clip-ons bars et al, since it doesn't cut it in the sports class, any more, is a point I’ve read mentioned in one or two recent write-ups, but I don’t see why not - even at 70mph the wind would be a real drag without them.
 

Practical things I like about it are, for instance, the seat pan, sidepanels and both mudguards are plastic, so no rusting problems. The shaft drive is an absolute must, surely, in this day and age. I think about all you poor devils out there fiddling about with filthy back chains and sprockets - yech.
 

Not least in its favour, is the agricultural simplicity of the whole thing. No mind bending techno wizardry, with built in obsolescence to give you sleepless nights about how much it will cost if this or that black box goes wrong. And no bits of it are difficult to understand or very expensive to maintain.
 

With its low centre of gravity, excellent balance and poise, together with user friendly braking - I question the logic behind the idea of being able to squeal the front tyre with just two fingers on the lever - it is what I'd call a virtually idiot proof bike; the linked braking system is a positive boon on slippery roads.

Home maintenance is a doddle. Two complete lube change a year, engine more often if necessary (it can go to 2000 or more miles). Oil consumption is practically zero, apart from some leakage from the crankcase breather - this drops off once you’ve allowed it to find its own level. Once adjusted using vacuum gauges and Colourtune, carbs remain set for months. The only reason why the carbs go out of sync is because the throttle cable moves about, upsetting the relative slide heights. Get that sorted and life is smoother for longer. Fiat contact breakers fit straight in and last for years with the occasional clean up in situ.
 

Rear tyres last around 5000 miles, maybe longer, and I usually change the front at the same time - Pirelli Phantoms only, I must stress. Pads last longer if they and the calipers are cleaned out regularly if the cast iron discs have gone rusty. Otherwise, they partially seize and the linings end up uselessly wedge shaped. Use a bottle brush to dust out the calipers, and use a file to clean the edge of the pads to ensure they slide freely in the calipers. Be warned, Ferodos may not fit properly and rip up the discs - use Brembos or the cheaper lpercos. Wet weather braking is okay so long as you keep the discs dry.
 

Generally, regular exercise keeps the brakes at their most efficient, but this can reqiuire more than just a trip to work and back every day. Bleed brakes with new fluid at east once a year - you’ll be surprised by the amount of crud that collects in the calipers.

That’s about it apart from valve clearance and ignition timing. The former are very accessible but re-timing the ignition unit is best done with the special tool to reach the awkward clamp bolts, which can be done without completely removing the fuel tank. The bike had a birthday recently, so I also changed the fork oil as I couldn’t think of anything else to do to it.
 

Problems? Final drive universal joint exploded because it was more than 25000 miles old. So, at 25000 miles new Cardan joint, OK? Can be done at home, if a bit fiddly, Most time consuming part is removing and replacing joint and support bearing in the swing arm. The original speedo refused to register more than 60kph.
 

All the calipers had at least one seized piston because they were not assembled with high temperature grease. Front wheel bearings wore out - changed in just half an hour. Exhaust downpipes are a heap of rust. Regulator needs a bit of waking up first start of the day, but I think know why (internal riveted connections are oxidized).
 

Mods - swap carb bellmouths for K & N filters, this is a must if you value the life of your engine. Also makes throttle response a bit more civilised (smoother take-up, less stop/go, stop/go). It’s not absolutely necessary to maintain ignition timing at the prescribed 8 degrees before TDC at static. Retarding back, even to zero TDC, makes it a whole lot smoother, more tolerant in hot weather and improves pulling ability at low revs, has no detrimental effect on performance as far as I can tell, if anything it revs easier.

Other additions included a rear carrier, pannier frames and a digital clock. Most recent mod was fitting of T4 spec silencers, which is a very strange thing to do with a Le Mans, but I’ve started touring again and after listening to the exhaust note for six or seven hours a day, day after day, the novelty of the great exhaust noise sort of wears off. But the worst problem is the lack of power below 4000rpm with the competition silencers on.

The result, although quieter, can still be made to snort and rumble something like a good old British twin might. More importantly, the power band has spread out a bit into other useful areas, achieving the desired effect of greater flexibility. Most noticeable is the absence of pinking when urged on at around 3500rpm (which normally fluffs it). It still revs quite happily and goes just as fast as it ever did. As I say, since acceleration requires co-operation of a heavy flywheel, any advantage that might be gained from shifting combustible compounds faster with the aid of a less restrictive exhaust system is largely wasted. Another hopeful side effect might be improved fuel consumption, which I am still in the process of examining.
 

Make no mistake about it, though, I have in my possession what they call a good ’un. But at least it proves what can be done with an early Le Mans model to produce a machine to which you can become quite attached. The Mk2 version is supposed to have better transmission than previously and includes a Spada type fairing - 'course, you can buy these bits separately and put ’em on whichever version you’ve got, thanks to the universal parts interchangeability feature of all the big twins.
 

And given its butch nature it doesn’t have such a rough feel as you might expect. Blessed with a 90 degree cylinder orientation offering perfect primary balance, even a Le Mans can be very smooth. I’ve surprised one or two pillion passengers who couldn't swear to feeling a thing (mind you, I wasn’t trying to ma seven grand).
 

I paid around £1800 for mine, for an eleven year old bike. It’s been worth every penny. Always starts first press of the button, cold or hot,. and is utterly reliable. They are built to last even if the engine is a bit of a lump. I used to have a flash BMW car that spent more time sitting at home doing nothing except letting its battery go flat.
 

The Guzzi is not just for leisure on sunny weekends, it is essential transport for all purposes. My new problem is to remember that people will no longer hear me coming from miles away. 

Mike Holmes 

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