Service

SERVICE

Rain-groove wobbler

I own a 1973 BMW R75/5, which I use mainly for touring and local riding. I’m having a problem I can’t solve: bad handling while riding over rain grooves. Fortunately, south Florida doesn’t have any, but they really have me at my wit’s end when I run into them elsewhere. Is there any way to ride on them without constantly feeling as if I’m going to dump my bike?

Stephen M. Conti Miami, Florida

Rain grooves, when they became common on the national scene, had motorcycle and tire designers at their wit's end as well, but current bikes are in general well-behaved while passing over them. The cure was mostly in the tire tread pattern. Current tires tend to have larger tread blocks, which are less likely to shuffle around white deciding whether they're reall y in the grooves or not. In contrast, purely ribbed front tires, common 15 years ago, behave badly in rain grooves.

Your BMW's rain-groove handling could be substantially improved by fitting an r of the tires that are standard equipment on new BMWs, or, for that matter, almost any high-quality modern tires. And while tread-pat tern subtleties may not always be obvious, st a r aw a y from ribbed fronts to achieve the best rain-groove performance.

Speed-demon XL80

I have a 1983 Honda XL80S, and while it’s pretty good in the dirt, it only has a 45-mph top speed that’s not so good on the street. Most of the time I use it for going back and forth to school, and I’d really like to raise its top speed to about 55 mph.

Is there any way to do that without spending a great deal of money? Beginning Rider Huntington Beach, California

The gearing on the XL80 hurts its top speed, and installing a front spocket with two more teeth or a rear sprocket with four fewer teeth would boost the bike's speed potential. Any motorc ycle dealer should be able to order suitable sprockets for you from a sprocket supplier such as Circle Industries. There is one catch to this easy speed increase: The taller gearing will hurt the XL's low-speed performance •> in the dirt.

Reader tips

In regard to S. Cameron’s problem with Interceptor valve clatter (October, 1984), I have an ’83 Sabre that had the same problem. The clatter was worst when the engine was cold, but it also was loud on downshifts and deceleration. I took it to three Honda shops before my warranty expired, and no one could hear it. I finally got one Honda shop to hear the noise four months after my warranty expired. They found that the rear cam-chain tensioner was sticking. Honda paid for the parts ($45) and I paid for the labor ($90). Be persistent and don't let your warranty expire like I did.

R. Dotson Cleveland, Ohio

In reference to D.J. Minor’s letter concerning warped front-brake rotors on his GS l 100EZ (June, 1984): My '82 GSI 100EZ went through two sets of replacement rotors in less than 10,000 miles, and that was in addition to the original rotors that were on the bike when new. Reno Honda-Suzuki finally determined that the run-out was at the point where the rotors attach to the hub, so they had the wheel machined. Result? No more warped discs and a tremendous increase in feel and braking control.

Hats off to the service manager. Norm, at Reno Honda-Suzuki for his bright idea.

Dale E. Wood Truckee, California S