Front brake wont retract - any ideas

cable is running through smoothly, no rust, no idea

try giving it a scare.

Sounds like a similar problem:
https://www.lfgss.com/thread57144.html

^Yeah, by me. Maybe the spring round the back is totally f*cked, so probably time for a new one. :(

What kinda caliper is it? Single or double pivot? Take the caliper off, clean it, oil the pivots (with 3-in-1 or similar, not WD40 because it doesn't last very long), put it back together, and re-install. It'll only take 30 minutes even if you're not experienced with spannering.

By retract, do you mean the brake wont close, or it wont re=open?

I had a similar problem - sounds like the spring.

Might also be worth oiling your cables. Friction within the cable housing can stop the spring from reopening the caliper.

^ If a cable needs oiling, especially a FRONT cable, it is fucked and needs replacing ASAP.

An excessivelly bent/twisted cable can also cause simialr issues.

Really? If the cable is fine but the lube in the cable housing has been replaced with road crap/water/etc. over time then wouldn't a clean and lube be all that was required?

You are not supposed to lube cables, they should run free & loose as is. A bit of oil can be applied to slightly corroded/dirty old cables to make them run a little smoother. But this is something done for rear brake cables, and only for cheapskates.

A front cable on a road bike is extremely short and shouldnt have much in th eway of bends in it. There is no reason for the cable to have any significant friction, if it does it is well past its use by date.

Cable housing comes pre-lubed, are you saying this is wrong?

Bit of oil on the brake pivots. I had the same problem, brake gunged up due to escessive winter grim, oil sorts it out.

look at the brake front straight on, see the bolt on the right above the brake pad? make sure it isnt too tight.

also, the bolt that holds the whole thing together (one end is hidden behind the front arm) shouldnt be done up too tight either. you'll have to take the brake off to do this easiest. have a play, its not hard to figure out what bit tightens against what bit. but as a tip, its not just a matter of loosening the allen bolt that holds the thing to your fork. both these things will make the brake sticky in return, or just plain not return.

squeeze the calipers together with your hands (not using the lever), if they return fine then its a problem before the caliper, such as knackered cable inner/outer, too much bendy kinkyness in the cable. another thing people overlook is the actual lever being too tight. depending on what lever you run there may be a pivot bolt rather than just a pivot. dirt harry is a prime example, its easy to get a bolt thats too tight so it messes with the return.

good luck.

oh, and what Buddha says about oil. just keep it away from the pads/rims and dont use wd40 except for cleaning cables (i am a cheapskate so dont replace inners unless they are too short/frayed {sometimes i just cut the frayed bit off} or too badly kinked).