Looking to replace my KH29’s brake system, lever and caliper. Pistons are sticking and the feel is horrid. That could be improved with a service but what I realy want is less lever travel than the current brake, which is the original M425. The lever travel is twice that on my cheap mountain bike and quite distracting.
I was looking at a new M8100 set. But which, front or rear? I know each ship with different hose lengths, but are the calipers the same and can either be used?
Calipers are the same and either can be used. The only differences between front and rear are the hose length and the master cylinder position - right or left, compared to the lever.
Well, calipers are the same for sure. For Shimano brakes, the levers are left or right handed (if that makes any difference to you). Most other brakes are ambidextrous (Sram, Magura, etc.). You could buy two boxes of rear brakes and set your b!ke up if you used Sram or Magura, for instance. The front brakes have shorter hoses. If you can get away with just using the front brake and not cutting it, that’s ideal. If you have to shorten the hose and bleed the system anyways, then it doesn’t matter which one you get.
Just make sure you get the correct mount adapter for the size of disc you want to run. Unicycle frames are set up for a 160mm disc without an adapter. This is the same as the front of a bike (rear bike IS mounts are 140mm). So it you want a larger disc, make sure you have a ‘front’ adapter. The rest of the brake is the same.
As far as i looked up in web, only diff between 6100 and 8100 are in the lever. The lever of the 8100 can be adjusted without tool. To adjust the lever of the 6100 you need an imbus.
That is why i have a 6100 break on both of my m4o unis and its ok for me. But i do not have any special requierments. On my paths around my home theres a lot of up and down, so i use the break a lot. But i don’t ride downhill.
I have no experience with the differences of 6100 and 8100, but im happy with my 6100.
A bleed and new pads might already reduce the lever travel on your M425, but if you upgrade to M8100, front vs rear doesn’t matter since the calipers are the same, just choose based on hose length (front usually works best) and consider a bigger rotor or different pads for a firmer feel.