Rear brakes does not return upon release

[mun.mun.mun]

Hello

I am not well versed with bicycle maintenance. Please forgive this.

I am trying to repair the rear brake of my sons' bicycle. The problem: the rear brake calliper arms do not return upon releasing the hand lever. How do I fix this?

From what I understand, this is a "side pull calliper brake".
The images are here: https://1drv.ms/f/s!Alv1g_QMvFFjjf1maA21ZIgsP6KQiw?e=AISa02

I have adjusted the front brake watching YouTube videos; however I am struggling with the rear ones.

Can anyone point me to the right video?

[Eyebrox]

Sounds like the inner cable needs replaced. If the lever stays put when you pull it towards the handlebar, this indicates a sticking cable. Could also be rust or crud on the brake bosses - or jamming up the noodle. Best check the cable first. Does it go slack and not return to its starting position? Replace it if so. The bosses and noodle will appreciate a squirt of lube too.

[drossall]

Yes disconnect the cable and see whether the brake, when squeezed by hand onto the wheel rim as though you'd applied the brake normally, returns when you let go. If so, it's the cable. If not, the pivots in the brake calliper itself need to be lubricated, either by squirting in something such as liquid grease, or by complete disassembly and greasing.

Don't over-lubricate, as grease/oil on the wheel rim is bad news for braking.

This sort of thing might help - there are loads of videos and pages such as this.

[Jdsk]

Welcome.

As above there are many possible causes and the first step is to isolate bits of the system until you've found the problem(s).

I don't think that YouTube videos are a good way to learn about this stuff, because if they don't exactly match what's in front of you then it's hard to know what to do.

But there are two wonderful maintenance websites:
https://sheldonbrown.com/rim-brakes.html
https://www.parktool.com/en-us/blog/rep ... a%5B%5D=48

... or three, if you include this forum! : - )

Jonathan

[Eyebrox]

I have just looked at your photographs. It could be that the brake is being restricted in its movement by an overtight frame bolt. Sometimes these bolts need extra washers (and grease) to allow the caliper to open and shut. I suspect the front brake will have worked because the fitting will be different.

[peetee]

The mudguard is bolted in the wrong position. It should be held on the other side of the frame tubes by the nut at the other end of the brake assembly. Once in place there you will need to adjust the two nuts that are located at the front.
1.Undo the brake cable so the brake spring opens the calipers.
2. Loosen both bolts (mentioned above).
3. The inner nut should be backed-off enough that the spring can work but not so much that a clunking movement can be felt if the calipers are pulled forward.
3. Once adjusted, hold the inner nut with an open-ended spanner and tighten the outer nut against it.
4. Re-attach the brake cable.
5. To centre the brake, if needed, undo/re-tighten the bolt where you have attached the mudguard.

[drossall]

The mudguard is bolted in the wrong position.

It does look very odd, and as though the mudguard bridge could foul the movement of the brake. It's normal to have it on the opposite side of that metal bar (the seatstay bridge) from the brake.

[Mick F]

The mudguard is bolted in the wrong position.

Spot on.

[plancashire]

So far as I can see from the photo the brake cable enters from below (step-through frame?). That means rainwater will run down into it, causing rust. Disconnect it from the brake calliper and try to slide it inside the casing by moving the lever and pulling on the now free end. If it seems stiff dribble some thick oil down it and keep sliding it back and forth. That may make it slide enough. If not, replace the cable and outer. Buy a small rubber boot as used for direct pull brakes and fit that to keep water out of the cable outer end: https://www.bike-discount.de/en/jagwire ... or-v-brake.

[TheBomber]

Following some very good advice on this question it’s probably ok to note now that you shouldn’t expect too much from those brakes. They have been built down to a (low) price so if you can get them working at all then consider that a success.

[peetee]

Following some very good advice on this question it’s probably ok to note now that you shouldn’t expect too much from those brakes. They have been built down to a (low) price so if you can get them working at all then consider that a success.

Nevertheless, the way they have been altered to accommodate the mudguard is potentially changing a poor brake into a dangerous one. The mudguard needs to be moved. If those two nuts are not locked together they may loosen enough for the whole brake to fall apart. It would seem that the other potential consequence is happening - that they are instead tightening up against the caliper arms. Again, a bad thing.
While it is possible that the nuts could potentially be locked against the mudguard mount it is highly likely that the spindle will not possess enough thread to accommodate the outer nut. As shown in the photo the slot in the mudguard is so wide as to require a washer so the nut can hold tight, but that would push it out further still. It follows therefore that in its present state, ie washer-less, it can only be inadequately attached and the nuts not fully locked - hence the problem of tight brakes.