Service

SERVICE

Fork stress

I have a 1978 Harley Sportster with 6-inch extended forks. One of the fork seals is starting to leak and needs to be replaced. My dealer said I should remove the extended fork because of what he claimed was added stress to the fork bushings due to the longer fork legs. Should I take his advice or not?

D.R. Passick Charlotte, Michigan

That's entirely up to you. But you should know that your dealer is right: The longer fork legs do increase the load—and, hence, the wear—on the fork bushings, which means the bushings will need replacement more often than they would with stock-length fork tubes.

Chain or shaft

My friend and I have been debating about the perfect final drive system. My friend says shaft drive is superior, I think just the opposite. If shaft drive is so great why do race bikes, both dirt and street, use a chain?

Mike Thompson Muncie, Indiana

Both final-drive systems have advantages and disadvantages. A chain drive is cheaper and lighter but demands more maintenance in the form of lubing and adjustment, and it also requires periodic replacement. Shaft drive requires little maintenance and conceivably could outlast the rest of the bike; but it is heavier and costs substantially more to manufacture than chain drive, and usually has adverse effects on chassis behavior when used on competition machinery. Most race bikes use chain final drive because it is substantially lighter and less complex than shaft drive, plus it allows much easier overall gearing changes and generally results in a better-handling motorcycle.

XT550 shock

Does anyone make an aftermarket shock for my 1982 Yamaha XT550? The original-equipment shock was a poor-quality thing that required replacement at 3500 miles. The bike now has 1 1,000 miles on it and the shock has gone south again. I bought this bike new and want to keep it, so the price of a new, adjustable shock is of little concern. But I’m having trouble locating a company that makes a shock for this bike. Please help.

Bob Peeples Tuscon, Arizona

Works Performance ([818] 7011010) can build a custom shock for your 550 that will greatly improve its rear-suspension performance. And the unit can be rebuilt when necessary.

A reader fix

I have a fix for Ronald Grasmick's Ninja ZX 1000 clutch problem (Service, April, 1989). The rubber piston cup in the master cylinder or one of the wheel calipers may have a tiny, hard-to-see hole in it. Replacing these parts in the master cylinder and calipers, followed by a thorough bleeding of the system, should cure the problem. It’s also a good idea to replace the brake lines with quality lines. I use braided steel lines from Russell. They are much better than the stock ones, and they cost less too.

Gray Devine

Nepean, Ontario, Canada 0