Originally Posted by
gadabout007
last two rides I've experienced issues with my brake cables. Both front and rear, but the rear is more extreme.
After about two hours in -5 to -7° celsius, my brake cables seem to get sticky in the housing. When I release the brakes the front brake slowly opens and the rear releases the tension, but continues to drag on the brake track. At stops I'm having to reach back and manually open the brake. It's definitely the cable or housing. If I squeeze the caliper together by hand it snaps right back when I let go. After warming up indoors for a bit the brakes behave normally.
Cables and housing were replaced this spring and are the same brand that were previously on the bike. I've rode in much colder temperatures and never had this problem.
I took the cables out and blew out the housing with compressed air thinking there may be water in the housing that's freezing, but that didn't solve the problem.
I've ordered some T9 waterproof lube as a last resort so we'll see if that fixes the problem next week.
Could this just be a bum set of cables/housing? The cable itself looks perfect, no rust or fraying, but I obviously can't inspect the inside of the cable housing.
The increased amount of friction in the rear brake, along with your good troubleshooting (caliper is okay, warmer temps is okay) screams to me freezing lube. The lube used in the cable housing is different than what it used to be. There may have been little/none before (with teflon lining that's not unheard of). I use a wax based lube and it seems okay.
Finally it may be that there is a bit of rough cut housing/liner which is okay when the lube is warmer and working well but the cold temps pushes it just beyond the cusp of smooth cable movement. The fact that both brakes are sticking says that this is not really the case. To check this you can loosen the cable anchor bolt and just slide the cables back and forth. You shouldn't feel significant resistance.
I'd clean the lube off the cable, "rinse" out the housing (WD-40 or similar solvent rich lube) and use a much thinner lube. I like White Lightning, it works well to about 20 deg F. Don't use as much lube as possible - that works well when it's pouring rain or you're going through stream crossing, but in cold weather you want a scant amount of lube so that there's room for the cable to move in the housing/liner.
Hope this helps.