Almost a year old thread here, but just wanted to give it the bump. Too all 200x owners, this thread is a godsend, including the CR85 rear M/C and front caliper swap to the back of my X that I just did.
I've simplified the thread a bit so you dont have to go through 75 other posts...
1. 2000 kx80 REAR caliper is a direct bolt on to the 200x FRONT using a 200x bracket.
2. 2003 cr85 FRONT caliper is a direct bolt on to the 200x REAR using a 200x bracket.
3. 2006 CR80 FRONT caliper is a direct bolt on to the 200x REAR using a 200x bracket.
4. 2002 CR80 FRONT Master Cylinder is a direct bolt on to the 200X FRONT
5. 1998-2006 CR80/CR85 REAR master cylinder is a bolt on to the 200x, though it requires two .375 spacers and also for you to drill out two holes. (see post 21/22)