Originally Posted by
shawnin van
I have an ebike and i like the brakes to bite hard.. they were like that on the stock brakes... my rear pads have stopped biting and will come to a long stop when pulling the lever. i have shimano brakes with m485 pads... i have tried new resin pads,, wont bite.. new metalic pads better but wont bite... i have adjusted them numerous times.. i have tried bedding the pads... no luck,,, i have cleaned and sanded the rotor.... what is the trick to get my rear brakes like my front??? to bite!! if i pulled my front hard id flip over the bars,,,, any ideas????
Perhaps they were never adjusted correctly. Here is the tailless one's beta on adjusting mechanical disk brakes.
The inner pad does not move. Rather, when actuated, the outer pad pushes the rotor into the inner pad, deflecting the rotor slightly. It would follow that if the outer pad has to push too far, braking power would be lost and the rotor miight take a permanent bend. I've also seen brakes adjusted so the inner pad is completely retracted, which means the rotor gets pushed against the caliper itself. Not much friction there.
So, loosen the caliper mounting bolts. Observe the depth of inner pad protruding clear of the caliper. Adjust pad depth so you have about 1.5 mm protruding. Now squeeze the brake lever, letting the caliper float. It should be on the tight side, that is, with less than 1/3 of the lever pull to make contact. Loosen the cable a little if necessary. Then, while fully actuating the brake lever, tighten the caliper mounting bolts. You can use a rubber band or old toestrap to hold tension on the brake lever. After tightening, release the lever, spin the wheel, and observe that the rotor probably clears the outer pad but rubs the inner pad.. Ignore the outer pad for now. Retract the inner pad so it just barely stops rubbing. You should still have more than a millimeter of inner pad protruding. With your caliper properly centered, you can now adjust the cable tension to your liking. I recommend 1/2 to 1/3 of free play to the handlebar. When you hit the brake, you should feel a solid "thunk" of the outer pad pushing the rotor quickly and firmly against the inner pad. If you don't get the "thunk," your inner pad is too far from the rotor.