Cable Outers - long or short?

[martint235]

So I snapped my rear gear cable the other week (I blame @ianrauk ) and replaced it with a new Clarks one. I cut the new outers to roughly the same length as was already one there but I didn't get smooth shifting, I could either have smooth up or down but not both. Anyways I took the cable off yesterday to put more grease on it in case that was the issue and messed it up as usual ending up with a frayed cable.

So new Shimano cable on order and it occurred to me that maybe the outers are playing a role in the shifting issue. Should they be longer to create a smoother curve running line or shorter to reduce the friction?

Thoughts?

 

[ianrauk]

My fault?

 

[martint235]

My fault?

I was p***ed. You sent me a text showing your rear derailleur and asking if it looked right. I went to check on my commuter. Snapped cable. QED

 

[ianrauk]

 

[Pale Rider]

The manager of my local bike shop reckons Clarks stuff is cheap but not very cheerful.

I reckon all will be well when your Shimano cable arrives - assuming you are getting a Shimano outer as well.

Greasing the cable doesn't sound like a good idea to me, I use a light spray lube such as GT85.

 

[Yellow Saddle]

Gear cables should never make small radii around corners. "Small" is subjective but a trained eye can tell you yah or nay. Perhaps look at some photos of bikes set up by pro mechanics? As for Clarks....well, it is rubbish. A piece of hessian rope moving through a calcified water pipe has less resistance. You'll never get good shifting with that stuff on narrow-spaced gears. Keep it for your old 5-speed setups.

 

[martint235]

The manager of my local bike shop reckons Clarks stuff is cheap but not very cheerful.

I reckon all will be well when your Shimano cable arrives - assuming you are getting a Shimano outer as well.

Greasing the cable doesn't sound like a good idea to me, I use a light spray lube such as GT85.

Yep full Shimano replacments. The description says the outers are already lubed but may spray some GT85 in too, can't hurt I suppose.


Thanks all for the responses. Well except @ianrauk who just seems to be trying to evade responsibility

 

[Yellow Saddle]

Don't spray stuff into your cables. It can hurt.

 

[martint235]

Don't spray stuff into your cables. It can hurt.

Thanks. Won't do that then.

 

[Pale Rider]

As for Clarks....well, it is rubbish.

My local bike shop sells - but not recommends - some of it to those on a very tight budget.

My experience of radii is the outer needs to have air space around it.

I had dodgy shifting on one bike which I eventually traced to the outer resting against a rack leg.

A squirt of GT85 where the outer ends on my Alfine 11 cable on the chainstay cured some sticking.

There is a little rubber boot, but it doesn't stay in its proper place so some muck gets on the naked end of the cable.

 

[Ajax Bay]

If in doubt go long for the final outer from the chainstay to the RD ie as YS has implied, make the radius bigger than perhaps it was before.

 

[Spiderweb]

Silicone type gloves if you like, put a drop of chain lube on your forefinger and thumb the pull the new cable through your fingers. Works great for me, I would avoid grease.

 

[ayceejay]

If you cut the outer the end will be crimped slightly and you need to fix that then make sure there is a rubber boot on the end

 

[Globalti]

Bad fitment of the RD cable will mess up your shifting. Make sure the radius isn't too tight. Make sure eveything is clean. If you must, wipe a little chain lube on the inner and allow it to dry, so as to leave a little wax. Make sure the ends of the cable outer are ground flat and properly fitted into ferrules. Make sure there's no muck or rust at the cable ends. Use Shimano inner cables, which are more flexible and smoother than bog standard bulk buy shop supplied cables. Don't smear grease on the inner.

 

[martint235]

It appears the maxim about buy cheap buy twice is true. Shimano cable fitted and shifter is as smooth as a smooth thing wrapped in melted butter