Breaking speedo cables every few hundred Kms!

[1983lux]

I keep replacing my speedo cable. Speedo seems halfway accurate and works fine, don’t hear a whine but then again bike can be noisy. Maybe something is occasionally binding up, causing the cables to break? Tried a couple aftermarket ones, just broke a stock cb900 one. Maybe have gone through 4 or 5 cables in a few thousand kms

[Fred Camper]

Wow, is there a sharp bend in your routing or something. Very strange to me.

[1983lux]

Not really any sharp bends, although I do have to zip tie it to the brake line to avoid it hitting the tire. I have a smaller fender on it than original, so it can't sit quite the same way.

[1983lux]

Here's a pic of how I have the cable routed, although hard to see the part where it goes up into the gauge but its a fairly straight shot:

cable2.PNG

[1983lux]

Maybe a bad speedometer? Perhaps if the cable is spinning faster at the wheel, and the Speedo is resisting and not spinning quite as fast, the cable could break from the strain?

[kerryb]

To isolate the problem, try removing the speedo and the cable from the bike so you can spin them with a drill motor (in reverse) in a quiet place to listen for suspect noises. Is the cable breaking closer to the speedo or the axle?

[redglbx]

Have you ever replaced the outer sheath ? I had one years ago that developed something inside that would catch & break the cable inside. I replaced the entire speedo cable inside/outside and never had another issue. Just a thought.

[Sidecar Bob]

Perhaps this S bend has something to do with it?

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[1983lux]

The cables always break closer to the axle! Yes, I’ve always replaced the cable and sheath. Hmm, I can get rid of that s-bend by routing it closer to the front of the light, might try that

[1983lux]

Hmm, wasn’t the cable that broke this time. The tang on the speedo drive itself down at the wheel broke off. How hard is it to find a new one of these?

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[tlbranth]

I'd be inclined to do what kerryb said. Could be a dry/seized bearing going into the gauge. I had a dry bearing in mine - whined like a genz with a dead phone battery. Took out the gauge upside-downed it and lubed the bearing with 3-in-1 oil. Been good ever since.

[Sidecar Bob]

Lubing the speedo may or may not help but it certainly wouldn't hurt. Same with eliminating the S bend.

BTW, how are you lubing the new cables? That greasy stuff that comes on them is just to prevent rust in storage...

[1983lux]

I had been spraying them with pb blaster ‘chain and cable’ lube in a spray can. Would you guys recommend something else?

[Sidecar Bob]

That should work.

[BlueThunder]

Nah... use DriSlide graphic lubricant. Lubricates better without attracting dirt and dust. The ENTIRE cable must be lubricated. Then put a small smear of Castrol bearing grease into the speedometer housing (where the cable goes). Repeat the above at the start of every riding season. Your cable will last a decade.