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The weight is over

Paul Dean

I've been dreaming about owning a Honda Shadow American Classic Edi tion Tourer, but one thing troubles me: If this bike is designed for road trips, how come its load capacity is only 381 pounds, including rider? Between my wife and myself, we can just about get to that weight without carrying any gear. Would different shocks or springs help this situation, and if so, by how much? Mark H. Bennett South Berwick, Maine

A motorcycle load rating is not determined by the shocks, the fork or even the frame; it is determined by the tires. Every tire sidewall lists infor mation that includes the maximum load that tire is rated to support, along with the inflation pressures needed to carry that load. So, even if you upgraded an ACE Tourer's sus pension, its rated carrying capaciti' (the combined load rating of the front and rear tires, minus the weight of the unladen bike) would remain the same.

The enemies of tires are weight and speed; when you combine exces sive amounts of both, something's got to give-usually the tires. But here `s what the tire companies can `t legally tell you: You can exceed the weight rating (though not by more than about 10 percent) without risk of tire failure if you keep the tires inflated to their maximum recommended pres sures when carrying that load, and never ride faster than the posted speed limits. Obviously, the handling will be somewhat compromised with all that weight on board, but the in tegrity of the tires will not.

Tire problems arise when, say, a 300-pound rider loads a 200-pound passenger and 50 pounds of luggage on a bike rated to carry only 400 pounds, then rides at or near tripledigit speeds on a wide-open road. Don `t laugh; it happens all the time. And if he rides this way for long, some form of tire failure is likely. Consequently, the tire manufacturers use weight ratings that generally are on the conservative side. But if you intend to run at sustained high speeds, absolutely do not exceed the bike weight rating.

Downshift dilemma

I just bought a `92 Kawasaki KDX200 that's in exceptionally good shape and runs great except for a problem with the transmission. It upshifts okay, but when I downshift, the gears don't engage. The transmission just goes into a false neutral and makes kind of a rattling sound. If I jig gle the shift lever up and down a little bit with my boot, it eventually will go into gear, but then I have to do it all over again for the next downshift. A couple of people I've talked to say that the transmission needs to be rebuilt, but I'm hoping they're wrong, because I don't want to spend a ton of money on a bike I bought as a "bargain." Jerry Molinaro West Mifflin, Pennsylvania

All the evidence suggests that the problem is not in the transmission but with the mechanism that selects the gears. No problem exists during up sh?fls, and you imply that the gearbox works properly once you go through the, monkey-motion required to complete a downsh~fl. This indicates that the trans mission is just fine, and that the prob lem is with the sh~fiing apparatus.

Your KDX is a five-year-old dirtbike, so it surely has fallen over dur ing a trail ride, probably more than once. Because "low-side" crashes are the most prevalent on dirtbikes, the sh~fl lever most likely would have been jammed into the ground and forced upward during a left-side fall. The sizable force of such an impact could easily have bent the shW mech anism return-spring locating pin, which also serves as a limiting stop for the shift linkage. A pin bent up ward in this way would prevent the mechanism from moving far enough during downsh~fls to engage the next gear. Or perhaps the shift actuation arm, which is the linkage piece that makes contact with the pin at full lever travel, could have gotten bent, allowing upshifts but preventing the proper completion of a downshift.

This is good news for you. Access ing the shift mechanism requires only the removal of the right side cover, rather than the removal and complete disassembly of the engine to fix the transmission.

Braking bronco

I have a 1988 Suzuki GSX-Rl 100 that has done a few miles and was, I thought, in perfect condition. Ap proaching a road junction recently at a reasonable clip and not having much spare braking distance in hand, I started to brake fairly hard when the front wheel began to bounce up and down, seemingly over its full suspension travel, in a quick "rat-tattat" manner. I couldn't back off the braking, so I had to hang on in "buck ing bronco" fashion. I lucked out but it took a while for my heart rate and blood pressure to return to normal. There never was a trace of this behav ior in nine years, and everything has the appearance of being okay. Could you suggest a likely cause? John Whitehouse Rockford, Illinois

My guess is that your GSX-R `s front end has insufficient damping, perhaps the result of too little fork oil, or fork oil that c overdue for chang ing. I also suspect that what you felt was not the front wheel bouncing upand-down the full length of its suspen sion as you describe, but rather the wheel chattering back and forth-a combination of the tire skipping off the ground and the fork stanch ions flexing somewhat every time the tire regained a bite on the pavement. The only other probable cause of such front-end behavior would be a warped disc or one with a hard spot on it, but you would notice this condition under other braking circumstances. Drain the fork and install the correct amount of the correct oil and your problem just might go away