Workin on my first build and figuring out the rear brake setup. Any reason a year 2000 Sporster 883 master cylinder wouldn't power a 1992 FXR rear disk brake system? If it'll work I can handle fitment issues. Thanks in advance.

Pic of work so far attached.

 

I think the master cylinder is for a four piston caliper. Is the 92 FXR a two piston? Don't know much about FXRs. Nice looking bike so far.

 

I ended up with a master from a 2002 sportster 1200. It's for a 4 piston set up and the FXR is a single. The folks at Barnett Harley say "any ole master will do..." We'll see. I'm thinkin a 4 piston would need more juice. It may make a single piston rear brake a bit touchy. The bracket I'm building is a bolt-on to existing holes so I can always back up and re-punt.

 

Well, 20 months later and the project bike is on the road. Stock 80 ci EVO, Paughco frame and front. 16 in rims and lots of Mig weld to fits. Paint by Bearden's. It rides like a I'd hoped and nuthin has rattled off so far...

 

Nice work! No better feeling than riding something you built yourself.
Who's fork is that?
What did you end up with on that rear brake?

 

Thanks. I'm having hoot. Forks are from Paughco. As is the frame. (very pleased with the quality) Rear brake is an OEM single piston from a 92 FXR pushed by a 2002 Sportster master cylinder. It all links to a Wyatt forward mount floorboard kit. I only had to shorten the connecting rod between the pedal and master cylinder. No adjustment to the mechanical advantage ratios. They give good response as is.

 

Amazing build. Kudos.

 

Very cool, unique ride.

 

Don't over think it the bore size of the master cylinder is all that matters and the rears are all the same, getting into 4 verses 1 piston and MC sizes is a front brake thing. Built lots of custom systems & bikes over the years.