Lost braking ability

[marshall2389]

I've lost most braking strength with my Quest 1.0 recently. The pads don't appear to be too worn, but I cannot get the black part that holds the pads close enough towards the frame to get the adjustment right. I can fully compress the brake handles in the front and rear and have very little braking power. This is with the inside pad being adjusted all the way up to the disc brake. Any suggestions?

Elliot

 

[pjotr320]

It may sound strange, but

It may sound strange, but cable routing can cause problems like this. I once had the same problem with Aquila brakes on a different 'bent. They do stop my Q451 nicely.

• 
  check cables for strange bents and wear, make sure then run smooth, all parts should be well seated (disconnect at brake and pull back and forward with fingers)
• 
  when neccesary, replace and lube new cable and/or housings, stiff Jagwire cable housings make a difference (watch out for pads and discs, those don't like lubing
  
  )
• 
  completely re-adjust the both brakes

 

[John Tolhurst]

Sounds like only one side of

Sounds like only one side of the brake is touching the disk. You can reposition the body of the calliper by loosening andn retightening its mounting bolts.

 

[Shakey]

Had the same trouble

Hi Elliot, I have had the same trouble.
It might be one of two things.
I found there is not enough adjustment in on the caliper mount to get the most out of the brake pads. Even with the caliper adjusted all the way "in", and the static pad adjusted properly, the cable arm still bottoms out when the pads are 1/2 worn.
I have tried a couple of methods to get more use from the pads.
- Cut a sheet metal shim exactly the same size as the pad (including tab & hole) then put it behind the "active" brake pad.
- OR put washers between the bike frame & the caliper mounting block to move the caliper closer to the disc.

One other problem I have had is that the pads are not positioned on the rotor completley. A small corner of each pad never gets used, so when each pad has been worn down 1/2 the thickness of the rotor, those 2 corners connect preventing the brakes from working. Pull your pads off & see if you have 2 little "corners" that have not bee worn down. They can be scraped off with a file or chisel.

Hope that helps.
cheers
Richard

 

[vonhazza]

I use a business card as a

I use a business card as a spacer to set pad clearance.

Question is it possible that the pads could have become contaminated with oil or grease? if so it may be neccesary to replace the pads.

 

[crazy_ebot]

I was having some trouble

I was having some trouble with my brakes (Quest v1.0).

I replaced the factory brakes with some shimano ones, then after the brakes went loose again, readjusted the outward facing brake point, shifting it closer.

I get a teensy bit of contact each revolution, but not enough to give me grief, and my front brakes are working fine now. My rear brakes... Kinda work; no matter what I do, I can't get them to match the strength of the front brakes. I'm learning to live with it.

There's a Quest version 2 now? Damn it... Internal gears, rear racks... How can I justify repacing my bike after 2 years? : }

 

[marshall2389]

Great suggestions

Peter:
I will check the housing soon

Shakey:
Thanks for the suggestions, I will definitely look into the 'unused corners' problem you mentioned.

Sorry for taking so long to respond. I forgot I posted this and there doesn't seem to be any notification system

 

[marshall2389]

Partial success!

The rear pads did indeed have unused corners that meet when I squeeze the brakes. I will grind those down when I can get into a machine shop. The front brake did not have the unused corners. I tightened all the housing and readjusted everything with modest results.

 

[Shakey]

No need for a machine shop,

No need for a machine shop, those raised corners will scrape off with a sharp edge.
Knife or chisel will work, maybe a light buff with some sand paper after.

 

[marshall2389]

Really?

What are the pads made of? I don't want to ruin a knife trying to take the corners off...

 

[alanst]

brake cable

I had the lbs replace my rear cable with jagwires, and it made all the difference. Apparently the bends on a quest's cable are too much for softer cables. I suppose hydraulics would work even better.