Speedometer cable installation (up or down?)

[Wanderer]

Morning. Is there an up or down for the speedo cable? On one end you can pull the inner cable out of the outer sleeve. Does that end go to the hub or speedometer? Does it matter? Thanks

 

[5twins]

I'm not sure that really matters (although it might). I was more concerned with which end of the sheath had the protection sleeve on it. I wanted that at the top where the cable snakes down in behind the headlight and rubs on the lower triple tree. I'm pretty sure that makes my cable inner pull out from the bottom.

 

[Wanderer]

Thanks for your reply..

 

[TwoManyXS1Bs]

.... that makes my cable inner pull out from the bottom.

I recall that's the de-facto standard for both bikes and cars. Without a shouldered stop, the cable could slide deeply into the drive's square socket, and lose engagement with the instrument.

Having the cable stop at the top requires having a mating stop shoulder in the top area of the sheath to arrest its slipping downward, and that area can go dry, with the cable lubricant slowly wicking downward. Although that would make it easier to service (simply withdrawing the core when disconnected from the instrument), there was some concern that this type of service may encounter difficulties getting the cable's square drive to re-engage the drive socket at the far end.

Having the cable stop at the bottom establishes a reliable fixed point as reference for the cable's dimensions, since the mating stop is simply the drive's output end. Simplifies sheath geometries and design. Eliminates lubrication issue with the core stop, since it spins with the output socket. And, eliminates the inadvertant disconnect at the drive side when the cable gets stuck in the instrument's socket during servicing...