Old Giant Twist brakes

[Leonardo]

I need a piece of advice for the brakes of my Twist Comfort Gts 2006. Both the front and the rear brake are "squeaking". I bought the grease for rollerbrakes, but I find the grease-hole cap only on the front brake. The rear one, which goes together with the Sram P5, isn’t it a rollerbrake? And what I can do for it?
Thank you for your help!

 

[flecc]

Here's the SRAM links for details on maintenence of your P5 Leonardo, it's probably the drum brake, and hopefully it will help you. Sadly not in Italian as you see, but I know that you are happy with using English and French:

Product Manuals & Quick Starts
SRAM P5
Gear Hub Systems
Operating instructions (Operation / Maintenance and care / Assembly of components)
SRAM P5
English / Deutsch / Français / Dutch / Dansk / Svensk

LINK

 

[Leonardo]

Thank you for the link flecc. It should be precisely the sram drum brake.
Unfortunately that product manuale doesn't say anything about brakes noise, nor about greasing... My problem is that in my town nobody use this kind of gears and brakes, so I have to ask your help to try to understand something... At the moment it seems that the only thing I can try is checking if there is too much drag in the brake pads...

 

[flecc]

These brake shoes that are in the drum are a bit like the car brake drums that they still often in use on the rear wheels. The usual treatment is to take them out and check if the lining material is worn out down to the metal shoes. That's unlikely though, but if very worn, best to order replacements.

Then clean out any brake dust from the drum, and to do that, take anti dust precautions, wear a face mask if possible. Use a vacuum cleaner hose to suck out the dust, and avoid breathing it in as it can be harmful.

Then a primary cause of squeal is a sharp leading edge on the lining material, so use a file to chamfer/bevel that so there's a smooth lead in on application of each shoe. That's it. Reassemble and try out. They will give an initial squeal as they bed in again, but should go quiet then.
.

 

[flecc]

P.S. You'll find that if you disconnect the cable and torque arm, then take the wheel out and remove the spindle nuts etc that hold the brake backplate, you can withdraw it complete with it's shoes. Don't forget about avoiding breathing in the dust though Leonardo.

 

[Leonardo]

I’m afraid that all this it is above my forces, flecc... the only solution now is to find the way to corrupt - or better blackmail - a mechanic in order to make him follow your instructions... Just one more question: is this noise only an annoyance or is it the symptom of a serious problem? Thank you again for your help.

 

[flecc]

It's usually only an annoyance Leonardo, and only causes damage when the brake lining material wears right through and the shoe metal is rubbing inside the drum. That then scores the metal. It's quite rare that they reach this stage though. Much depends on the usage. If you've done lots of downhill work with the brake held on for long periods it may be worn in that way.

If scoring has occurred, it's usually not too serious a problem as new shoes and linings will still work, just have a small loss of efficiency and a slightly higher wear rate. The linings aren't supplied separately, you just replace the two shoes with new SRAM spares.

It's not a difficult job to check out for yourself if you are able to take the wheel out you will be able to remove the brake backplate. However, any competent cycle mechanic can do the job, or if you know an experienced car mechanic, he'll be even more familiar with what's needed since they do exactly the same work on most cars' rear brakes.

 

[Leonardo]

I'll try to do what you suggest flecc