87' 250r to 450r rear brake conversion

[honda109]

does anyone know what parts are used to convert an 87' Honda 250r to a 450r rear brake set up? Can I also use the whole rear master brake assembly as well?

[J250r]

http://www.exriders.com/vbb/showthread.php?s=&threadid=155875

I have a caliper I would sell you. All boxed up ready to ship.

Edit: So pretty much you need, brake stay, caliper, and rotor/hub assembly

[BULLET99Z28]

Very easy to do. The sticky thread is spot on. I use the M/C, hose, res, caliper, caliper mounting plate and 450r anti-fade assembly. I had to make a little bracket for the reservoir, basically drop it down about an 1 or so from where is mounts on the air box, cut the hose and run it under the exhaust stinger. Use the 250r swingarm bushing in the caliper plate(brake stay), just file it flat on 2 opposing sides so it fits in the 450r caliper plate slot. Use 2 8mm washers between the caliper and mounting plate just as explained in the sticky thread, and you will be good to go. Works great. All you need to do is lengthen the brake pedal pushrod or use the pushrod out of a 250r m/c. if you want pics, I can post them up.

[honda109]

thanks alot, Im going to give it a whirl since trying to find parts are getting hard and when you do people want so much.

[Rich250RRacer]

When I originally did this, I only went with the caliper since my master cylinder was good, but if it should go bad in the future, I'll add the master. The most critical part of this is the washers. I spent a lot of time measuring to find two that were exactly the same. Bulk washers can be as much as .020" different. If you can find some machined washers, it will save some grief.

[BULLET99Z28]

Another thing that I have been meaning to try is a different clevis at the end of the pushrod. Right now to lengthen the 450r pushrod I got a little hex type threaded piece from ace hardware and a matching piece of threaded rod, and adjusted the brake pedal postion to my preference. I know there are Billet clevises available for MX bikes, and those clevises are taller, it may eliminate the need for the 250r pushrod when using the 450r master cylinder. I will keep you guys updated.

[mx91a]

Originally posted by BULLET99Z28
Another thing that I have been meaning to try is a different clevis at the end of the pushrod. Right now to lengthen the 450r pushrod I got a little hex type threaded piece from ace hardware and a matching piece of threaded rod, and adjusted the brake pedal postion to my preference. I know there are Billet clevises available for MX bikes, and those clevises are taller, it may eliminate the need for the 250r pushrod when using the 450r master cylinder. I will keep you guys updated.

I just had the same problem trying to mount up the 450R master cylinder, the push rod was too short. So I went to the hardware store, bought an 8mm x 100mm threaded rod, welded on an 8mm flange nut and ground it down to the mushroom shape. I then installed all the 450R hardware to the new rod. Fits perfect! I plan on using the 250R reservoir hose fitting as it points inside towards the frame and not straight up like the 450R one.

http://i97.photobucket.com/albums/l209/mx91a/My%20Documents/IMG_0216.jpg

http://i97.photobucket.com/albums/l209/mx91a/My%20Documents/IMG_0206.jpg