81 250r disk brake swap

[81Rmachine]

I want to put disk brakes on my 81 but cant find a rear master cylinder. Does anyone know if one from a 2nd gen will work? could someone show me some pictures of their 82 master cylinder so I can see how they mount?

[nick walke]

hello sir

try using a dr350 rear cylinder - i made up an alloy bracket and went straight on
, its quite easy .
nick

[fahque99]

What would you use for a rear hub to replace the drum on the axle? Would a 82 and newer disk hub work?

[200xman]

You would need an 82 swinger and axle. You would also have to make up a master mount and get a pedal to work. Seems like a lot of trouble for nothing. I can lock both tires up on pavement with my 81 R with the drum brake.

[fahque99]

Are the 81 and 82 axles different? Different spline count?

[200xman]

The 81 has a third bearing in the drum backing plate and I believe the spacing from the sprocket hub to the axle nuts is longer than the 82 axle.

[fahque99]

But with custom brackets would it have worked? I am welding up a new swing arm so the brackets wouldnt be a big deal, I just need to know if the hub would fit on the axle splines. Mabey it needs a machined spacer?