disk brake super stiff

[johnny gaijin]

i've got an mb5 and the front disk brake is super stiff. it'll work but i have to squeeze the hell out of the lever to get it to move. what's the likely culprit? i'm a bicycle mechanic so i've got some related experience with disk brakes but i've never seen a bicycle with this problem.

thanks guys.

 

[iagsxr]

Caliper piston's stuck.

Pull it off, retract the piston with a c-clamp or whatever, notice how hard it goes in.

Or once had a bike that the brake line was blocked with solidified fluid. If the piston goes in easy break the line and pull the lever, see what comes out/what it feels like.

Or you could have goo in the bleed back hole in the mc. not releasing pressure, but the brakes'd likely drag.

 

[Rocan]

rebuild your caliper, and change the cables etc.

does the mb5 have a cable caliper or hydraulic? if hydraulic, go with a stainless line.

another issue could your master cylinder needing to be rebuilt as scale sometimes gets into the passage ways making the brake caliper movement slow.

 

[johnny gaijin]

does the mb5 have a cable caliper or hydraulic? if hydraulic, go with a stainless line.

hydraulic, i didn't even realize motorcycles used mechanical disc brakes.

 

[bikeboy]

i didn't even realize motorcycles used mechanical disc brakes.

I think a couple of early honda discs were cable? Did last long tho'

ian

 

[Big R]

The cb200's have a mechanical disc brake.

You can spot a cb200 rider by the size of their right forearm- about the same size as their thigh......