Cycle News - Archive Issues - 1970's

Th e Honda -was totally undisturbed by water, as Bern ie delighted in proving by d oin g giant belly-flops off a two foot ledge into three foot deep water with a shifty sand bottom . Besides being an amphibious tractor, the brakes shrugged off water as well. About the Honda, Bernie said: The ground cle ar ance was reaIl y limited. To clear the bi g boulders, I h ave to float th e front end just right. The front end felt like it was more raked out and h ad more wheelbase (than me others). Going through rocks, it didn 't seem to tum as tight. Overall weigh t takes away the advantage of handling. Takes muscle ge ttin g the steering to waggle, getting the front end up. I was getting more tired on the Honda. Boyd added: It needs to be put on a weigh t-watchers diet. Bernie: Makes an exceIlent hillclimber, though, and the brakes stay dry , and it's got good downhill braking. No grab, no fade. Tracks good, tracks best of all at speed. Boyd: The brakes are OK, y o u really let the engine do most of the work. Took awhile to get used to th e way en gine braking throws you forward when you shut off. It 's noticeably front-heavier than the rest. I fo un d I had to develop a whole new sense of timing to deal with it . . . Honda's chain tensi oner (though circlip retention is bad) is better protected than the rest. Bernie: Sidestand sti cks o u t bad, I hooked it several times on roc ks. And bent the sh ifter. Boyd: Th e Japanese h ave a go od front hub. I lik e where the kill button is, me levers , con trols and bars are all OK . Seat is very comfortable. At 225 pounds, th e Honda was the he aviest, but to give them cre di t, Honda has used metal to best effect, even if there may be to o much o f it . Bernie hung the bash plate while attempting a sheer bluff, missed his footing and free -fell abo u t 30 feet ba ckwards. He was shaken, but the bike was hardly bent. Hondas are stron g. Th e fac t that Honda's lates t works trialer weights about 200 pounds wet is tantalizin g, but probably means little to the owner of a curr en t TL 250. An alloy tank, extensive drilling, and a different ex hau st will save some pounds, but n ot that much . New bodywork won't narrow th e wai st o f the bike, as the fram e is bellied-out in that region to clear the bulky muffler can. Peg width, at 17 and one-quarter inches, is the greatest of the lot, and ground clearance, at eight and three-eighths, is the least. No matter how good the engine and susp en sion might be , (and th e Honda is go o d ) these things p u t you at an irrevocable disadvantage. During th e te st , the Honda developed a bad tendency to stumble when the throttle was snapped open from very low idle , a problem also en countered on the TL 125 oc casionally . If cleaning or jetting corr ecti on s won't cure it, possibly loosening the valve clearances to abou t 0 .25mm (on e tum) greater than standard will help. This, in effect, de creases valve duration and exhaust/intake overlap, which in t um increases "draw" through the carb at very low speeds. It works famously on the TL 125. In an overview, it's hard to say where the TL 250 will make it in the market, whether it will be bought for a very versatile cowtrailer or for a basic trials bike. It is stone reliable, and its four-stroke power delivery m akes it uniquely con troIlable , but a two-stroke trained rider will have to re -train himself to ad ap t to it . ago to be alm ost as b ad as th e Kawas aki, but qui ckly evol ved - into a much-improved motorcycle. By ad din g flywheel weigh t, chan gin g the forks, diddling the rear sus pension, an d matchin g a ch oice of bars to their bodies, seve ral AT A ride rs hav e been com petitive in clas s with this super-light, slightly overpowered trial er, (Ed it or 's note: As it turn ed ou t, th e jo ke 's 6n us in calling t he RL 25 0 "most im p roved, " f or U. S. Suz u ki swe ars up an d do wn th at the on ly th ing t he y 've changed is th e tan k. What it does mean, however, is t hat th e firs t Ex actas tes ted by Cy cle Ne ws staff and by our gu est rid ers, were n ot set up p erf ectl y eit her at th e dealer or distri bu tor level; wh ereas th e latest ones are "n u ts on." What this furt her suggest s, is that it takes th e average dealer/d istributor network alm ost a y ear to "learn" a new model - and con sidering th e history of many o ther m otorcycles w e can recall, that sho uldn 't be an y surprise.) Bernie (Su z) showing w hat y ou can do on a wet log - if you're good. HondaTL250 A tractor with a sagging belly & an excessive avoirdupois problem. Had it not been for the disruptions of the " en ergy crisis, " the TL 250 probably would have been in production a y ear ago . The first prototypes were that "ready." It 's still a slick looking p ack age, though with a year's retrospection, its shortcomings have been pretty well studied. First, it weighs a lot. Second, it has a tall en gine, which means limited ground clea rance. Th e exhaust system is bulky , and tak en alongside the airbox, it forces the waist of the machine to be significantly wid er at the rider 's kn ee s than any of the others. What it has going aw ay is it's unique (among its peers) slow-churning four stroke torque. It wiIl sit with the front brake locked and dig a hole in the ground at a slow idle for as long as you want to dig a hole . The engine is virtually unstoppable. What is more important with ca bby traction is th at the power pulses are spaced farther ap art in time than an equivalent two stroke, and also are more effectively damped by flywheel inertia. This means that with an equivalent throttle lo ading, the four stroke will hold traction where a two stroke would spin. - Table I - Riding performance Rider/Section Kawasaki KT 250 Honda TL 250 Bernie/E x-Am 2 0 Boyd/Ex-Am 5 5 W III a. :; et u w Z et oJ >- III Vl a I- a < J: a. Yamaha TY250 The winnah! Tada-a-ah. .. It weighs 2 15 poun ds wet, wh ich puts it ne xt to th e Honda in the de ad weight department. It has oil inj ection , whi ch most co mpetitive trialers throw as far as th ey can throw it. Th e cases at 13 inch es width, are the fattest. Physically, it looks far b ulkier th an th e other t wo-s tT O kes . Yamaha TY 250 t t IIG Yamaha TY 175 Suzuki RL 250 t 0 0 5 Jeff/Nov 5-0 t 0 t 0 Chris/Nov 3 0 0 2 1 Yet it won our rider evaluation in a walk. Why ? The riders were unanimous. It was simply easier to ride, easier for a Novice, easier for an Expert. The trap scores bear this out, as regardless of who was on its back - Bernie, Boyd , Chris or Jeff - th e TY 250's scores averaged the best. St atistics only vaguely poin t to the TY 250's secret. The footpegs are Well-ma rked test section. virtually on a line with me swingarm pivot. The effective swingarm length on the test bike was the shortest at 15 and one-eighth inch es. Ground clearance, at nine and three-quarter inches, ties with the Suzuki , though me Yamaha has less pe rce ived tophamper. (The steering head is about three-fourth inch lower than the Suzuki.] It boils down to detailed refinement, m atching suspen sio n to engine to rider, dialing it in until it's right and then building them so they're righ t for the largest cross-secti o n of riders. The TY came off as eas iest to steer, easiest to loft and carry the front end, easiest to hold spotty traction with throttle co ntrol. The only gripe about rider com fort - two out of the four testers said the bars were too low. Footpegs and seat rated high from all. Case protection could be better, but it's adequate. Th e circlip on th e TY 250's chain tensioner got bashed by a rock, but didn't co m e off. The shifter had to be moved up out of harm's way. The test bike (a late '74) had a typical " Big Brother:' kill switch , which Boyd tweaked once with his knee, as he did on the Kaw. The 250 Yamaha's rear springing was The water test. oJ oJ ; --~ The best (Yam, above) and the worst (Kaw, below) in the footpeg race. • ~ t l!") rO'l rl - far firmer than any of the others, which, when combined with slightly anemic rebound damping (yes, even the "winner's" shocks co uld be a lot better) gave the rear end a nasty kick over sharp ledges and obstacles struck at speed. Its biggest weakness was an Achilles ' heel airbox. Apparently, water being ch urned back up over the top of me reat tire sprays right at a vulnerable j oin t between rear splashguard and seat bottom. (On the TY 175, the rear' fender extends in one piece all the way down to the swingarrn at front, eliminating this problem.) At any rate, spirited watercrossing flooded it every time. After a lot of cussing and discussing, we at least found a simple re-starting drill. Throttle closed and choke full on. That shuts off oil flow from the throttle-controlled oil pump, yet allows a heavy dose of raw, oil-free gas to wash off the wet plug until it finally lights. Takes about 10 kicks and a few false starts to dry it out. Once identified, the chin k in the armor is easily fixed with yaller goo. So, in spite of its few faults, mere you have it - th e best Japanese 250 trialer in the unanimous judgement of fo ur riders, two of which are committed to riding Spanish machinery and, consequently, spoiled rotten., If anything explains its lackluster sales, it's th e fact that it still doesn 't beat me Spanish bikes in head-to-head competition and isn't cheap enough (cutthroat discounting aside) to beat them on price. - Kawa saki suspenders totally used up. Yamaha TY175 • Newest kid on the block is a banty rooster. The TY 175 is as cute as a bouncy puppy. We predict that everyone will fall in love with it, but only big kids and small adults will consummate a marriage. Not mat a six-footer can't ride it, as long as said six-footer doesn't mind a similarly-equipped 12-year-old riding circles around him. The basic engine and some of me suspension seems to have been borrowed from other models in me Yamaha family of dirt singles and somehow thrown together so it will work. There are humongous toothed bosses on the lower frame rails that indicate footpeg mounting points for an other model. (Possibly a " tri als-en duro " designed for sit-down riding?) The fork legs extend a fat two in ch es beyond the upper fork triple-damp. A cost-effec tive method of adap tin g an off-shelf leg to trials ste erin g geometry, most likely. (Continued on page 42) ... 27

• Cover