Yamaha For 1978
YAMAHA FOR 1978
When the Yamaha technicians whipped the dust cover off the bike at stage center, the press responded with cries of “Oooh” and “Aaah” and “What is this, some kinda joke? What are you guys up to?”
Sparkling under the spotlights was the dohc Four seen last spring at the 1977 dealer show, except that at close range the first detail noticed was the badge. It says “XSllOO.” When the model was announced it was supposed to be a lOOOcc engine. Something was going on.
Yes, the Yamaha men said. We told you before it was a 1000, but it’s always been an 1100. See, we wanted to tell the dealers we had a model coming that would compete with the lOOOcc engines from Honda, Kawasaki and BMW. We knew we wouldn’t have the production lines moving until late in the year. But we didn’t want the other companies to know we were going to have a larger engine than they have. So we fudged on the displacement a bit.
Understandable, if a trace tricky. What matters is that the XSll, as the factory calls it, is Yamaha’s new flagship. The other details remain as they were announced earlier, that is, transverse-inline Four, not quite the 750 Three with another cylinder added but sharing some parts and designs in the cylinder head, valve and inlet tract. Rated power will be somewhere between 90 and 95 bhp. Yamaha’s official statement is that “The fastest box-stock production motorcycle on the market in 1978 will be a Yamaha.”
The XS11 naturally has shaft drive, double front and single rear disc brakes and cast wheels. The rear tire is a massive 5.00x17 in. Styling strikes us as attractive. The XS11 looks big but heck, the XS11 is big. The square headlight is conventional sealed beam and the rating is exactly that of a round sealed beam; the shape has been chosen for looks and perhaps to make the Four more readily distinct from the Triple, which shares the maroon color.
A complete road test will naturally appear here as soon as the American branch of Yamaha has bikes to be tested. Meanwhile, the press had a short time to ride the XS11 on Yamaha’s test track in Japan.
It’s an impressive machine. The test track has a longish straight, slightly downhill in the direction we were riding. The fastest man in the group was clocked at 135 mph and change. The advantage given by displacement is power without fuss and the XSll surely has that. The Four is uncannily smooth and quiet at all times. No sign of any powerband at all, simply more power instantly as you roll the throttles open. The bikes in the initial test batch had more slop in the transmission/driveshaft/ ring and pinion than expected. Yamaha engineers agreed with this assessment, saying the clearances were fine when the drivetrain was being designed, but somehow the first examples were looser than specified. That will be fixed in the production bikes, they promised.
The first rides were less impressive in turns. A shaft drive doesn’t react the way a chain drive does and shafties must be ridden in their own way, a way which few of the press are accustomed to.
The XS11 worked fine as long as it was doing one thing at a time, that is, accelerating, cornering on a steady throttle or braking. When two or more forces were applied, as when the rider brakes into a corner or gets on the power coming out of a fast sweeper, the XS11 displayed either a low-frequency oscillation of the bars, in the case of the slower chaps (right, this reporter), or a genuine wobble with enough power to skip the rear wheel off the
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ground, in the case of the racers in the crowd.
Isolating the cause or magnitude is impossible for the moment. It could have been a case of a touring bike being ridden on a race track at full speed by riders who weren’t used to the bike, the track or the instant leap across eight time zones. The suspension calibrations may be involved; there are pre-load settings front and rear and the Yamaha mechanics varied them on request, but there was not enough time for serious tuning and there was a feeling that the settings are still being worked on for production. At any rate, the engineers involved with the XS11 accepted the press reactions calmly, so we’ll wait until production models can be put through the standard at-home paces.
Likewise for claims of speed. Remembering the flap last year when a certain 650 was introduced as a 750 killer just in time for a new and quicker 750, one hesitates to confirm or challenge Yamaha’s promise. We knew about Kawasaki’s hot new Z but we didn’t know if Yamaha knew and it wouldn’t have been polite to tell. We’re sure gonna have some fun at the drag strip, either way.
SR500
Next up on Yamaha’s new model list is the SR500, an actual case of response to public request.
Basically the SR500 is a street-only version of the already successful TT500 and XT500. Same engine, with at least one major difference; same basic frame and suspension, but with a low exhaust pipe, lower fenders, restyled tank and rear fender, etc.
Not much of a surprise. Soon as the XT500 arrived, we suggested a road-only version patterned on the big British 500 Singles of the past. We’ve since seen a couple fine examples of the XT reworked into road-only trim.
Meanwhile back at the factory, scores of letters arrived from people who said they’d buyjust such a bike. Many were from guys who’ve owned motorcycles in the past and would like to have another, except that they aren’t interested in the small utility models and aren’t keen on the large and complicated Multis. If the little scoots are known in the trade as entry bikes, surely the SR500 is the first re-entry motorcycle.
The adaptation is nicely done. The simplicity and basic appeal of the big Single may be classic, but the details of the SR500 are for the most part modern, i.e. disc brakes front and rear, cast wheels, selfcanceling turn signals and a proper seat. Styling is perhaps based on the old British clubman bikes, specifically BSA. but not to the degree that somebody who’s never seen a Gold Star will think he’s looking at one.
Which brings up something of a debate. At the de-briefing session after the test circuit riding, the Yamaha engineers asked for reactions to the omission of electric start. The younger reporters wondered if having to kick wouldn’t be a hassle, as 1) the Yamaha 500 Single is famous for not liking to fire when hot and 2) a stall in traffic or on a hill can be damned annoying. The older hands were vehemently opposed to electrics. Leave us, we said, one motorcycle with some skill involved. Leave us free to do what the inexperienced men can’t do and besides, you want tradition? Here’s the place it belongs.
Hard to start? asked the engineers with sly smiles. One of the men in the second row reached beneath his chair and produced an SR500 carburetor, just like the XT and TT model except for the little button below the throttle bell crank. Push the button and the throttle is barely cracked, to exactly the correct setting for the engine when hot. You set the button and kick with throttle untouched. When the engine fires, a blip on the grip will pop the button back out of the way. Nice work and the TT500 owners in the audience immediately had visions of retro-fit.
The choice of tire wasn’t as clear. The models at the test circuit wore sort-of replica tires, of a pattern like that used on the 500s of yesterday. There were comments that the tire was too slick for the bike’s power, also that tires are no place to relive the past. Again, Yamaha’s reps seemed to take these comments well. Likely modern road tires will be used on production SR500s.
Tires or no, riding the SR500 was simply a delight. The bike is light, the engine is strong, the geometry seemed perfect and there’s ample power. We saw 90 mph through the traps, which is enough for most everybody. We came away highly impressed. If the XS11 will get most of the attention, it will be competing against a flock of other good and similar machines.
The SR500 is in a class by itself.>
XS750 Special
This will be the year of the Cruiser. Yamaha didn’t have any off-road bikes on display with the truly new models. They’ll come later. What they did have as a chorus line for the stars was an assortment of production versions of established models, in semi-custom guise. The theme is also present in Honda’s 1978 line-up, witness the test and preview for that make elsewhere in this issue. Research done by the major companies indicates there’s a market for bikes which appear redone by their owners. There’s a hint of chopper but not exactly, so the factories have chosen cruiser as the key word.
Top of this particular line is the XS750 Special. It’s the normal 750 Triple engine, shaft drive and all, wearing a teardrop tank, stepped seat and higher handlebars, angled back in the manner of what used to be known as ape-hangers. The seat strap has been replaced by a grab bar aft of the seat proper.
One genuine engineering change for the 750 Special is leading axle forks. Unusual move. BMW began using leading axle forks, oh, 10 years ago but the big push currently is for motocross and pure enduro bikes. Yamaha has retained the centermount axles on the XT and TT and is using them on the new XS11 and SR500, yet here are leading axles on the XS750. It’s obviously easier to design for such a change, which requires flatter triple clamps, different tank, etc., than to modify an existing design.
The XS750 Special forks seem to be something of an experiment. The advantages are the same on the street as the dirt, mostly more wheel travel and longer engagement for stanchion tube and slider, which gives less friction and less flex. Yamaha engineers said they had to start somewhere, so they picked the XS750. How well does the idea work? we asked. We hope you’ll tell us, they said.
XS650 Special
Perhaps the most natural model for a cruiser package is the XS650. The big Twin has a steady and loyal following. Year after year Yamaha brings out another with modest fanfare and year after year the model sells well. It’s a bulletproof bike, traditional and all that, and 650 buyers are likely to make their own changes. So the 650 Special probably fills a need.
Actual changes are minor: teardrop tank, higher, pulled-back bars, shorter exhaust pipes, grab bar behind the stepped seat. Cast wheels and disc brakes are there anyway, so nothing is lost with the appeal to the stôck-custom market.
XS400
The cruiser package for Yamaha’s 400cc Twin is the biggest jump in terms of standard model with different looks. The regular XS400 is the closest to racey of the big four’s utility 400cc models, with low bars, cafe rear section, flat tank and seat.
The cruiser 400 has teardrop tank and pull-back bars, rear grab bar, etc. Fenders are chrome-plated and the looks of this 400 are quite different from the other 400, albeit the two share engine, brakes, sixspeed transmission, etc. The XS400 is also the slickest of the three Specials. In effect, the 400 buyer has the clearest choice of the group.
Also, for the record, the three specials shown here are additions to Yamaha’s range. They do not replace the stock, so to speak, versions of the 750, 650 and 400.
P.S. Readers may notice a distinct lack of specifications and dimensions in this article. Despite flying the press to the home plant and providing test rides at the track, Yamaha had some problem with the fact sheets, none of which were available at the introduction, nor did they arrive at press time. Sorry ’bout that and the gaps will be filled soonest. [§]
