erm sounds like the springs inside the calliper are broken. don't open it up you'll never get it together again. need a new calliper or brake.

usually on mechanical discs, there is an adjuster screw to close the back pad...


what your describing is.... you have pulld the swing arm too much and left the cable shorter than what it is... let the swing arm all the way... tigten the cable then adjust the back pad.

I had the same problem on a Quad Mechanical disc brake at the weekend.

Very simple internally, with the outer pad adjusting in with an Allen key as usual, so no problems there. The arm turned a round widget with grooves in over 3 ball bearings. The grooves started deep and got shallower, so as the round widget moved it pushed the pad against the rim. There was a floating insert that stopped the pad from twisting.

To allow the arm to return back into position it used a coil spring common to V-brakes and cantilevers etc. This locked into a hole in the caliper and then a small hole in the arm. Thus as you moved the arm you coiled the spring, and consequently it unwound. Around the spring was a rubber seal.

Investigation into the Quad brake showed the the sping had un-hooked itself from the actuation arm, therefore it wasn't returning. It was easy enough to re-assemble and seemed to work ok in the workstand. On test riding the bike it locked itself on again however. This time the spring was still working, and a gentle push would pop it back. My guess was that the rubber seal was jamming up around the spring as it had some wear marks on it. However the problem was still there upon removal.

So, in short, I couldn't see any reason for the pad locking onto the rotor.


In the end the chap bought a Shimano Deore Hydro Disc.. £60 fitted. No hassle.

Dave

Scrap it.

Buy a Shimano Mechanical one for £30 or a Deore Hydro for £60.

Dave

get the deore over the mini, the new deores are fantastic for the price.

running a set of deores on the ht, 180 front and 160 rear, i cant think a nicer set of brakes for the price.

if it hadnt been £170 to put a set on 200/180 rotors and £210 for some juicys then a set would have gone on the dh bike as well.

bargain of the year.