Motorcycle Safety & Driveability: Speedometer cables, speedometer cable, wd 40

Question
Pat, Please consider this as a generic question about Motorcycle speedometer cables, and the expected life.

I'm driving a 1982 Honda CM450E twice a week 40 miles to work.
Over the last year, the speed needle has begun jumping about while under way at constant speed. This has gotten worse in the last month.

After having a front tire tube replaced, the center square cable slid out of the black neoprene housing, and was lost. I bought another via Ebay and installed it myself. Very satisfied. Works well.

But now I'm wondering about the expected life of speedometer cables.  I KNOW I have put 11,000 miles over the last three years on this bike.  But I am unsure of the prior history of the bike. I suspect it was being "parted out" and can't confirm the cycle's 14000 miles were all it had when I bought it. Don't know if the cable was original equipment, but it might be.

What should a street rider watch for? What signs that one should be replaced? How long would you expect one to last? I've been told tires have an average life of two years, dependant on your usage, etc.  Mine have both been replaced in different years, once each during the four years I've owned the bike.

Thanks for looking at this as a generic safety question, Pat.  I trust your experience.

Answer
A speedometer cable, if cared for (i.e. bike is not left outdoors uncovered for long periods of time without being ridden) should last at least the life of the motorcycle. Once you start moving them from bike to bike, you never know how many miles its got, but having them go bad on you is the exception, not the norm.

A speedo cable is not a wear item like brakes or tires or fluids. If you want to help ensure yours lasts the rest of your bike's life, give it a little bit of lube--a squirt of WD-40 at the top into the tube/wrapping, let it drain down and soak the cable, then wipe off any excess that drips off the bottom. Maybe do that once a year on an old bike, twice if you put a lot of miles on it.

In the meantime, keep an eye on your tachometer. Know what speed you're traveling in each gear at each rpm, then when and if your speedo goes, just leave it and use the tach as a speedo.

Pat

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