Replacing rear outer brake cable

[JaAnTr]

Hi,

Might be a stupid question but I have internally routed cables and was having an issue with my back break not reopening once I had closed it. I replaced the inner cable but this didn't fixed it and I've narrowed down the problem to the outer cable going from the top tube/seat post to the calliper as there seems to be too much friction to allow the cable back. I've tried greasing the cable but it's not working. So I need to replace this outer but I'm not sure exactly what I'm looking to buy or if you can just buy this. It's probably only about 10-15cm long. Cheers!

 

[CanucksTraveller]

Yes you can buy outer cable - But you find it in rolls and then you cut it to length, here's one example by Jagwire which are used by many major manufacturers:
http://www.chainreactioncycles.com/jagwire-lex-4mm-slick-lube-outer-gear-housing/rp-prod151022

The really easy option is to get an LBS to fit one, they'll have outer cable in the workshop already, they'll cut it to proper size nice and neatly, and it'll be fitted snugly into your frame hole. You can do it yourself of course, but you need the cable, possibly new connectors and a gaiter, the cutters, and the time; I'd rather pay the LBS the £15 or so and be done with it.

Having said all that I think it's worth removing the old one first and giving it a good flush with GT85 or similar, put the little pipe on the spray can, connect it to the outer and give it a good blow through. It could just have crud inside it which is stopping the cable moving. Outers very rarely need replacing.

 

[Sharky]

The symptons you described could also be caused by sticky calipers? Have you tried operating the calipers by hand with no cable attached?

But hope you solve the problem.

 

[simongt]

Had this issue recently; rear brake sticking. Cause was the cable was corroding AND fraying inside the sleeve - ! Arrgghh - ! Stripped the old cable out, flushed the sleeves with TF2 and put is a nice new stainless steel cable. Ah, what fun it was to thread the cable through the brake lever and line it up with the end of the sleeve immediately behind the lever - ! All put to rights, then realised the l/h brake arm was sticking as well. So off with it and one clean and lube later, presto, a nifty rear brake again - !

 

[Ajax Bay]

Outers very rarely need replacing.

Would you like to elaborate on that? What do you mean by 'very rarely'?

 

[CanucksTraveller]

Would you like to elaborate on that? What do you mean by 'very rarely'?

These things are relative of course, I've had to replace cables themselves umpteen times but I haven't yet had to replace an outer myself. I'm aware others will have, and when I've owned bikes with outers for much longer, I'm sure I will at some point too. I've only had bikes with outers for 6 years, before that it was all external steel cables.

Is that accurate enough this time? As an aside, I think it's a real shame that users with helpful intentions find themselves constantly having to tread on eggshells to carefully select almost non-committal phrases when an OP has asked for a simple bit of advice, and yet been ignored all evening. Some members are always very quick to step in when there's points to be scored however.

 

[JaAnTr]

The symptons you described could also be caused by sticky calipers? Have you tried operating the calipers by hand with no cable attached?

But hope you solve the problem.

I'm pretty sure the problem is the outer, the caliper works fine springing back open when I close it by hand. I also went for a rider today with out the outer on, so cable going straight from top tube/seatpost into the caliper and it was fine. GT85 down it sounds like a good idea though, I'll give it a try.

 

[Ajax Bay]

I've only had bikes with outers for 6 years, before that it was all external steel cables.
Is that accurate enough this time? As an aside, I think it's a real shame that users with helpful intentions find themselves constantly having to tread on eggshells to carefully select almost non-committal phrases when an OP has asked for a simple bit of advice, and yet been ignored all evening.

I must admit I haven't come across bikes that have brake cables without outers (for parts of their travel). Though I dimly recall that my first tricycle and bicycle had rod brakes.
The purpose of your short sentence "Outers very rarely need replacing." was, I presume, to suggest to the OP that the problem probably wasn't the outer (though he had said it was). But I don't agree: brake performance relies on sound cables and the outers wear. Perhaps you are not riding much or are careful and gentle with your braking to get such longevity from your cables. Someone on here commented that he changes his outer every time he changes his cable (which seems a bit excessive) - so there is a spectrum of opinion.
Perhaps I should have just outright disagreed with you, but my question was designed to extract the rationale behind your assertion.
I note that the OP had greased the cable already. A good squirt is fine but likely the outer needs replacing, even if the squirt works for now.