Neil_B

My ride today I scrubbed because of my continuing problems with my front left brake. When I squeeze the brake lever, it moves into contact with the rim, but doesn't move back when I release the brake. As a result I'm getting rubbing on the rim and the wheel won't spin freely. This has been an on and off problem with the bike the past couple of months, but it seems to be getting worse. Today it defied all my attempts to adjust it - cleaning the brakes, rim, and tire, resetting the wheel, tightening the cable, tightening the screw on the brake that adjust tension - none of them seem to work. Help. Please. My self-confidence as a cyclist is at an all-time low, and I need to be riding.

Mazama

Sound like a lubrication issue, maybe within the cable housing. Have you tried shooting some oil down through the cable housing? Is there any way you might have a frayed cable?

jaxgtr

Hey Neil, I agree with Mazama, shoot some oil down the cable housing. Also, do you still have the stock brakes on that FX? Are they the tektro? Mine finally bit the dust after 5 years and I replaced them with some Shimano LX brakes and they function much better. Replaced the cables and housing as well. Found them on the net for about $20 and put them on myself in about 30 mins.

audiofx

This happened to me a few weeks ago after getting mine back from the LBS after a tune up.

I took it back to the LBS and they adjusted the front wheel with the quick release lever. It took about 10 seconds to fix. I have a Trek 7100 hybrid.

I kept toying with the brakes and it ended up being the wheel.

vXhanz

Not sure how your brakes mount... but mine had a similar problem a few weeks ago. I had to tighten the allen nut that was used to mount the brake to the front fork. Took me a while to figure out that the allen nut was threaded through the back of the fork though.

Otherwise you may just want to replace them if they are stock and have been on there for a number of years.

V

Mr. Beanz

I had a problem with my front caliper. I tightened the nut then noticed it wouldn't retract. I had tightened it too much. Has to be just right, tight enough but not too tight.

v1k1ng1001

I think historian is talking about cantilevers though. Do you have regular cantilevers or V-style cantilevers? Can you post a pic of your set up?

Neil_B

Mr. Beanz

NEVERMIIIIIND!

Neil_B

What sort of oil should I use?

bigtruck

Neil
Have a look at this and down the page Spring Adjuster,
https://www.sheldonbrown.com/canti-direct.html

This may help , I can't really tell by your photo your brake set up
but have a look anyway

v1k1ng1001

So check this out. The "spring" on one of your vbrake cantis might have worked itself around the tab (on the far side of the brake) on the brake lever that it is supposed to contact. This would mean that the remaining spring is pulling both levers hard to one side. If you just flip that spring back into place it might help to balance everything out. This happens on my old Vbrakes every so often, especially when they are left slack during transport.

v1k1ng1001

Here is a better view of the spring. See how it is contacting the inside of that tab (near the very top of the spring)??? If it gets round that tab, the other spring will pull your set up off center. Both springs have to be on the inside of that tab for your brakes to center properly.

cohophysh

I second what viking said, check the "spring" he mentions, I've had one work loose before

Neil_B

Both springs appear to be fine. In fact, that was the first thing I checked.

v1k1ng1001

Hrm!

What happens when you unhook the brake cable, remove the rear wheel and move the brake levers? Sometimes the pivots need to be cleaned or simply wear out.

If that's not it, I'd try loosening everything and setting the brakes up as if they were new.

One thing that I've noticed is that bike shops often set up v style brakes so that the brakes engage very early when you pull the brake lever. I think it is because customers tend to think that early engagement with the rim means that the brakes are more responsive/powerful. This isn't true.

Setting up your brakes like this is bad for two reasons. First and most obviously, it leaves little room for your rim to clear the pads and leads to persistent problems like this, especially with V style brakes. Second, if you can engage the brakes by barely tapping the lever, you have zero brake modulation and you actually have to pull much harder to get the same braking power.

I always set up my v brakes so that I have to pull the lever just short of the grip to get full stopping power and more rim clearance. It might seem weird at first but it is the best way to set them up. They're mountain bike brakes after all. They're designed to be ridden with two fingers on the lever at all times.

v1k1ng1001

Oh, and sometimes the springs just get bent too. So you have to gently bend them back and use the spring adjust screws to fine tune everything.

CliftonGK1

Check that the pads aren't worn down. As the pads wear, if you don't adjust their contact angle with the machined surface they lap over the bottom edge of the braking surface and can 'catch' on the rim.

Neil_B

The pads are OK. The pivot on the left doesn't seem to be working properly. Since it's overcast and threatening rain, I'll take the bike to the shop and have them look at it.

Neil_B

I tried to clean the pivot, and I still have the problem. It only moves away from a rim a little bit when I release the brake lever. And with the brakes disconnected, there's play in the left brake - it doesn't resist when I move it. So it must be either the pivot or the spring is bad.

Siu Blue Wind

I was juuuuuuuuust going to mention this. It happened to me when someone thought they knew what they were doing and tried to install my brakes. When I had the same issue I found the spring was bent waaay out of shape. I ended up bending the spring little by little until it was nice and even.

bdinger

I think it has something to do with the brakes on the FX. Mine developed the same problem and nobody could seem to get it right, regardless of adjustment, the first time I'd hit the brakes it'd rub. Finally gave up and just adjusted it out loose, and it worked. Added some kool-stop pads and it actually stopped .

Neil_B

The shop adjusted it in five or so minutes for me. Other than adjusting the brake on both sides, there's nothing special they did.

Michel Gagnon

Nice to hear that your problem is solved. I'll refer you to the huge photo in post #12 so you'll know what to do next time.

Typical adjustments.

1. Make sure nothing prevents the arms from moving one way or the other. It's a problem when the loose end of the cable hits the fork blade or a pannier, for example. Not an issue in your case.

2. Work with the two tiny "Spring Adjustment Screws". Don't tighten them too much because it's easy to strip them. Ideally, they should be out by 3-4 mm on each side, but basically, you balance them so they work. This solves most problems.

3. If that doesn't work or if you remove the cable and have the feeling that the arms don't move freely around the posts. Remove the Brake arm attachment bolt and remove the arm. With WD-40 or another good solvent, clean both the bolt and the arm of all the dried grease and grit, dry and then grease the post and reinstall.

DieselDan

Everyone missed one thing. The spring fits into a fitting on the cantilever boss on the fork. The spring maybe installed in the wrong hole, keeping it from rebounding properly. Usually, the spring goes into the middle of three holes, but if it is in the lower hole, the rebound is less. You may be able to remedy your problem by moving the spring into the top hole.

Trek is known to install low quality brakes on this model as well