In the early seventies when the first trail bikes began to make any real impact on the motorcycling public, they were basically road bikes with knobbly tyres and high handlebars thrown on to make them look the business. These tyres were often made from such a tough rubber that they outlasted the engine, but along with tiny SLS drum front brakes made fast riding on tarmac fraught with danger.
On the rough, the useless suspension, the questionable steering geometry and often ill conceived weight distribution, meant that the bikes would bounce around and throw the rider off with all the ease of an angry horse, unless the rider was highly skilled or very lucky. That any were sold at all, and most were used on the road, was down to their raunchy looks, cheapness and a certain degree of fun inherent in lightweight two stroke singles.
Predominant in this ballgame were Suzuki and Yamaha. Right at the beginning of the decade Suzuki were leading the way with the TC120 Trail Cat, a device that used a 120cc 2-stroke engine with a four speed box that could be turned from road to trail ratios at the flick of a lever, giving an effective eight speed box.
Like the later TS range, the engine was quite tough but could quite easily blow its main bearings or seize up. A straightforward engine design, it was easy enough to strip down and rebuild, but the bike is so rare now that you’re very unlikely to find a good ’un.
Of the TS range the TS250 stood out as their most useful device, although neither the 125 nor 185 versions should be easily dismissed. The 250 was introduced in 1973 and made it to 78 without any major changes. Subsequent models had dodgy engines, although the chassis was actually quite useful for green laning. It was the best looking of all the trail bikes in early editions.
Handling on the road was a little queasy above 50mph, with the trail tyre stepping out on wet corners with rather too much ease and many were the youngsters who were rewarded with a dose of gravel rash from an overdose of throttle.
The motor reached its development climax between 1977 and ’78 when it’d take the TS to 75mph and return 65mpg. Running costs were minimal, save for swinging arm bearings that lasted 6000 miles, chains that went in 7500 miles and a disturbing penchant for blowing light bulbs with amusing frequency.
Engine life goes from between 15 to 25000 miles before needing a comprehensive rebuild. But the 250 was tougher than either the 185 or 125 that could blow up with less than ten grand on the clock.
Off road riding was good for a laugh. You sort of have to hang off the back of the seat to make it wheelie at speed, and it liked to land on the front wheel and cartwheel bike and rider into the rough stuff.
Prices for any of the TS bikes vary enormously and their condition is so removed from their age, given that you could ruin one in a month’s hard trail riding, that you can only go to have a look at one and see what it runs like. Try anywhere between £50 and £275.
Slightly more useful off road, but not so pretty, the Yamaha DT range sold by the boat load in the seventies. Available in 125, 175 and 250 versions, the DT 175 was universally acknowledged as the best of the bunch, having the most usable combination of mass, power and toughness.
Introduced in 1973, as an update to the not dissimilar CT2, this 171cc 2- stroke managed 16hp, 70mph and 60mpg. The reed valve engine had a wider spread of power than the TS, whilst the frame was tougher, the suspension little better but the geometry more useful and the bike less prone to nose diving on the rough.
On the road the handling was no better than the TS, although it was slightly less easy to fall off. Thrash the poor old thing hard on the road and the engine will blow up, with a certain penchant for blowing crankcase seals and/or burning holes in pistons.
The tiny front brake was probably the worst of all the trail bikes, with terminal brake fade and quick wear pads. Chains lasted a little longer than the TS, tyres a little less and the electrics were more reliable.
Both the 125 and 250 versions are no worse road bikes, although the former is a little peaky and tends to be thrashed, whilst the latter vibrates enough to put most of the sex shops out of business.
Ever a little ahead of the game, Yamaha got serious for the eighties by fitting the DT out with monoshock - although the bike was useful in the dirt it wasn’t so versatile as the older bikes on the street. Prices are, again, unrelated to age, but as a road bike it’s perhaps best to avoid the 175 as this was the most popular bike for off road abuse. Anything from £50 to £450 depending entirely on condition.
Kawasaki were always much less obvious in the sales stakes, their bikes usually defined as being too heavy but more reliable than their rivals. The KE series didn’t hit the streets until the mid seventies and the 125 and 175 had some of the style of the Suzuki, but were the slowest of the bunch. Of these two the 175 is the one to go for, weighing only twenty pounds extra and having quite a bit more go.
A little later Kawasaki introduced a 250 version which made 22hp and weighed in at 2751bs. This didn’t prove to be very reliable, something to do with the crankshaft writing itself off due to lubrication problems and handled like both tyres were deflated on the road. All of these seventies Kawas are very rare, so you’ll have great difficulty finding one, but expect to pay between £50 and £250.
Honda initially kept well clear of the two stroke camp, concentrating on their XL250. This single cylinder four stroke was both overweight and underpowered in comparison with the strokers. Like the older British four strokes, the engine was not entirely reliable, liking to eat camshafts, tensioners and camchains, not to mention the odd piston and complete gearbox. To compound the problems of the XL, it didn’t deliver bags of low down torque and would shake merrily away under hard use.
Off road it was a complete slug, especially in its early form (’73-'76), when the tendency to go straight through rather than jump over obstacles doubtless helped explain the ease with which the frame could, er, break.
On the tarmac, with 20 horses to shift 300lbs, things were a little more enjoyable, although the limitations of tyres, brakes and suspension were all too apparent beyond 55mph, when the beast would waggle and wobble if you were foolish enough to try to lean it over more than a few degrees or became at all violent in your cornering techniques.
The front brake was one of the better fitted to these aged trail bikes, fuel could be quite reasonable at around 60 to 70mpg and with a bit of attention to detail (like fitting a different set of forks and wheels) it could make a useful road bike. Prices go from £50 to £200.
Rather more usable off road was the four valve head version introduced in ’78. The XL250S boasted a large front wheel, a few less pounds and despite claiming no more power than the earlier bikes was good for nearly 80mph, but only in a straight line, please.
The engine is not dissimilar to the RS250, with the same chain driven balance weights and the same self destruct urges. The S also boasted an awful gearbox that needed the kind of boot pressure leading to quick wear booties and a twin port exhaust system that were out just after the warranty expired. It’s difficult to work out if the XL250 is better or worse than the XL250S, both have their problems and are little longer lasting that rival strokers. Don’t pay more than £300 for an S.
The replacement for the S was the XL250R, a similar engine with a mono-shock rear suspension set up, that like later Yamahas was a much more serious off road bike than earlier efforts and therefore of little interest to street poseurs.
Honda were rivalled in the four stroke camp by Kawasaki, whose KL250 hit the streets in ’78, and like the early XLs was a bit of a laugh off road but quite useful for tarmac burning. The engine was nicely straightforward and produced rather more low down power than the Honda. It could gently coast up to 75mph, but would return as much as 7Smpg. Brakes were dodgy, handling soggy and there was far too much mass on the front tyre for off road rambling.
Probably the least useful of the off roaders, it has its uses as a cheap commuter or hack. Updated until ’83, it gradually became more usable off road. Prices go from £75 to around £750 for the latest stuff. Engines are the most reliable of the trail bikes, only prone to rapid piston wear if you forget to change the oil.
Beyond 250cc, the territory is taken over by the four stroke singles. First amongst these was the XT500, a device quite famous for refusing to start at the most awkward of moments and for throwing off riders with less skill than world champion scramblers.
The SOHC single cvlinder engine looked just right, but was spoilt by poor low speed pick-up and a dodgy gearbox selector. Although 30hp wasn’t all that much to write home about, it was more than enough for the chassis to cope with off road, the speed and mass would turn the world upside down very rapidly.
Piston wear and valvegear wreckage are not uncommon on hard used bikes. Top speed on the road is around 90mph, whilst fuel comes in somewhere between 40 and 60mpg. It does eat up chains, swinging arm bearings and front drum pads quite rapidly.
The 500 was updated to the XT550 with a four valve head and a twin choke carb to give improved low speed torque for a faster getaway, and, despite the use of a balance shaft in the engine, it was both faster and more economical than the 500. Beware of the weak clutch and rapid wear of the mono-shock suspension components.
In 1584 the XT600 took over, combining a front disc brake and improved rear suspension to make it the most usable of the big singles, although the reliability of the engine isn’t quite all it should be due to poor piston rings. Prices for the big Yamahas start as low as £200 for an XT500, £350 for an XT550 and well over a grand for the 600.
Honda’s 500 was never as inspiring as the Yamaha, although emerging a few years later it had the time to develop a more civilised motor and off road habits. Early versions are quite rare, and like the later mono-Shockers, not helped by the way it eats cams. Prices from £350 to £750.
The Suzuki SP370/400 was often thought of as the best off roader with a better combination of mass and power than most 2505 or 500s. It can have a dodgy top-end and breaks the kickstart gear, but otherwise a fine little roadster and quite usable off road. The 370 was faster and more economical, the 400 slightly more reliable. These are very rare nowadays but worth the effort of hunting down.
Of recent times, only the Yam XT350 stands out as offering anything like the older bikes combination of fun and practicality, but this device had such appalling styling that its appeal to road riders is strictly limited and like the XT125 and XT250, they suffer from cam problems if thrashed.
But forget post ’80 stuff, for the most part they have lost the elements that made the seventies bike so much more fun to ride. There are loads of Italian bikes and rarer Jap beasts that haven't been mentioned because they are so scarce and/or unreliable.
Although the earlier bikes were both hopeless off road and dubious on the tarmac, they were (and still are used) cheap and cheerful fun that also just happened to look a little flash. You just can’t get that kind of deal these days. It’s also quite easy to update them with suspension and brakes to make them better road bikes.
Al Culler