All, I'm turning a WR250R into a "Wr250X." The front brake is sh!tty. According to Cyclepedia, the only source I have, the X came with a 12.7mm front mc, while the R came with a 11mm front mc. Front calipers are different part numbers, not sure of piston size for X, though they are both similar designs. My question is can I just swap an X front mc on my bike without worrying about the caliper? Is piston size the only factor here or is there more to it?
I kept the same master and swapped the X larger rotor with caliper spacer and it had all the brake I needed. it's been a while, but i'm pretty certain the rotor bolt pattern is the same as a 1st gen. R6.
It looks to my untrained eye that the calipers are the same between the bikes but with different mounting brackets. So if you swap just the MC you should get a brake that feels like an X. I don't know enough about fluid dynamics in a brake system to say that a larger MC feels harder or softer, but if the X is a larger MC it will move more fluid (in theory) when you pull the lever, assuming that the lever pivot and ratio is the same.
IIRC, the 'hot' setup is a CRF250/450R caliper on the Yamaha bracket. Both are Nissin but for some reason the Red spec'd one is preferred.
X or R they both suck. I rode my wifes X once at a supermoto trackday and couldn't believe how shitty the brakes felt.
I have a Motomaster 320mm rotor and stock caliper spacer available, the rotor bolt pattern fits a Honda CR but I also have the hub carrier if you have Excel Gen 2 hubs. It was on my YZ450F when I bought it.
Thx, but I think I'm gonna get a WR X mc and see if that takes some of the squish out of the lever. This is a street application, so I'm not sure I need any more stopping force....yet. Just trying to improve the feel.
Did you ever get your R brake to feel any better? I've got my X for sale, if you are interested in looking at the parts on one.
