Brake Cables

clu

Hi everyone

I would like to ask for some advice from the knowledgeable people that use this site, sorry for the long post.

I want to replace the brake cables on my road bike, it has a complete shimano 105 5700 groupset. The problem I'm having is that when I'm riding and the temperature is really cold, I have an issue with the rear brake completely locking up when I've use the brake. But when the temperature is mild and not freezing the rear brake doesn't lock up it works, but the braking doesn't feel smooth I squeeze the brake lever and it feels rough. The front brake is ok and works fine, I don't have this problem at any temperature.

The left STI/brake lever is ok because the movement seems smooth/fine regardless of the temperature and the rear brake caliper moves ok and doesn't stick/lock up regardless of the temperature as well. I've been able to work both when I've been able to slacken the brake cable and they both seem smooth during operation. So therefore I can only assume that I need to replace the brake cable. I might as well replace both (front and rear brake cables) as a set.

Shimanos PTFE cableset seems to be available at the moment, but they are described as for use with dura ace 7900 and ultegra 6700. Does anyone have any experience using these and are they compatible with my 5700 levers?

At the moment I have Jagwire brake cables, they were already fitted to the bike when I bought it. I've read that people seem to rate the low friction Gore brake cables, but these seem to be hard to get hold of. I'd like the sheaths to be black.

Any advice would be welcome, cheers.

Wooliferkins

A brake cable is a pretty inert object and while you describe the symptom well you do not describe any fault finding. Even in Brizzle it's not got really Baltic yet. I'd take the cable out and see if there is any visible fault, clean, give it a wipe of lube and refit, check your lever and caliper but I would guess some water ingress in the cable. The Gore cable systems are nice but Gore have pulled out of the cable business so any Gore branded cables will be the last available. Shimano road cables will work across the range

clu

Thanks for the advice. Hadn't really thought about taking the cable out, but I guess I should have. I usually jump straight to replacement if I have a problem, but wasn't sure about if the cables I was considering were compatible with the levers.

I was wondering why the Gore cables seemed to be sold out everywhere I looked, so your comment has answered that query too. They did also look a bit more expensive than the other cables that are available.

Anyhow thanks.

smidsy

More to do with road conditions I would have thought or the fact you use thick gloves in winter so may be squeeing harder without realising.

The cable outer could feasibly be acting differently (less flexible) I suppose due to cold, but that would be true of any outer if it was the case, so you would still see a difference even if you 'upgraded' the cables and outers.

The Jagwire you already have are good cable sets.

If the wheel is locking yo need to brake less innit!

Monty Dog

Sounds like water/dirt ingress and simply freezing due to the cold. Try giving the cable and outer a flush through with some WD40 or GT85, dry-off and apply some wet chain lube. Gore cables are loved and loathed in equal measure, but going for a shielded cable like Avid or Goodrich is a good, reliable compromise IME. I use Goodrich on a number of bikes including my MTB which has frequently been ridden up to the hubs through water in winter and yet survives sub-zero rides without issue.

crankycrank

Clu wrote:

I want to replace the brake cables on my road bike, it has a complete shimano 105 5700 groupset. The problem I'm having is that when I'm riding and the temperature is really cold, I have an issue with the rear brake completely locking up when I've use the brake.

You may just have some moisture trapped in your housing which freezes in cold weather. You should also undo the cables completely and check for fraying, rust or damage to the cables and housing. Not sure which Jagwire cableset you have but their best "Racer" kit is as good as anything so no need to switch brands if everything looks good.

vespario

Gore cables aren't all that.

My cannondale came with jagwire cables and I upgraded them to jagwire racer cables. The business!

desweller

It could also be the pivots in the brake caliper itself. Whip the wheel and brake blocks out and douse the brake pivots with WD40, then run some heavier oil in.

clu

The cable housing has Jagwire L3 on it, so not sure which one I've got. The bike is a 2011 Trek 2.1, I did a search but couldn't find any info about what cableset was supplied with the bike. It's my commuting/winter bike.

Anyhow the cable that runs under the housing did have some dirt on it, so I've wiped the cable over with some GT85 and put a small amount of oil on it. I've also flushed out the cable housing with some GT85 too. With reference to the comments about moisture getting in and freezing, I'm thinking that's possibly what maybe happening along with the dirt on the cable.

The braking action does feel better now I've dealt with it, but I'll see how it goes when the cold weather returns. Thanks everyone for all your comments.