rbnfrance

Hi All,

I have just bought a 'Giant' brand mountain bike which has Shimano Cable Disc brakes. I can't find a record of the model number for the brakes, but I'm trying to fine tune them. My problem is that only one of the disc pads is a moving part and the other is static. The static one can be adjusted with a screw, but its one of those screws that clicks as it turns so that it has set positions. I can adjust that one so that it is either touching the disc or about 1.5 mm away. The other moving pad does not seem to be adjustable. I keep looking for a way to adjust it. Should there be a hidden screw or is it possible that you can't adjust this one. I can move it closer or further away by changing the screw that attaches the disc brake mechanism to the cable itself. I would like to use that to adjust the cable tension though, rather than the position of the pad in relation to the disc. Any ideas how to adjust it?
Many Thanks

MichaelW

Only the static pad has an adjustment screw. I find that its best to run the pad as close as possible to the disc without causing any drag.
You adjust the moving pad with the cable, either the cable retaining bolt or the barrel adjuster at the brake lever. make the adjustment so the lever causes bite at a suitable position.
If you have never used discs before, you need to bed the pads using braking heat.
Find a hill, get some speed up and apply the brakes hard but not to skid. Keep speeding/braking about 10 times until the disc is really hot (don't touch, it will burn).
Do one brake at a time.

AEO

static should be touching slightly, or nearly touching the rotor. The pads will "set in" after you use it for a short while and they won't rub. If there is too much of a gap, it can lead to brake squeal and warped rotors if they overheat.

BCRider

If the adjustable non moving pad is only scuffing lightly then live with it for a day or two. It'll likely wear and set itself to the ideal clearance of almost zero. You'll then need to monitor and click that pad in as it wears. For off road riding with some serious braking check daily. For commuting check weekly.

The gap on the movable pad is variable and is set by the postion you set with the clamping of the brake cable. You don't set the tension of the cable with this. Instead you alter the clamp to the cable so that you get the amount of free travel at the lever that you want. At that point the pad clearance is whatever it is. It may be a little or a lot but it doesn't matter at all as long as your lever reaches the engagement point where you want it to be.

rbnfrance

Thanks a lot for your 3 answers. I'm kind of new to this, and have not had a bike in 15 years! No disc brakes back then. Is it worth buying some better hydraulic disc brakes?

Many Thanks,

Robin

cobba

Not always so, with some Shimano mechanical disc brakes the outer pad can be adjusted with a allen key the same way as the inner pad can.

The BR-M465, BR-M495 and the BR-M545 are a few examples of this type of brake.

rbnfrance there should be BR-M with 3 numbers somewhere on the brake caliper to identify what model brake you have.

Info on how to adjust Shimano brakes: https://techdocs.shimano.com/techdocs/index.jsp?

If you were going to upgrade to hydraulics, you'd need new shifters too if your current set up is a brake lever/shifter combo.

The Avid BB7 is generally regarded as the best mechanical disc brake you can buy.