johnzboy Posted April 30, 2013 Report Share Posted April 30, 2013 I cleaned up a set of yfz 450 calipers and i am trying to install..... The shee was an 87. It is now an a arm frame and also installed a arm spindles. The prob I am having is that when I try to start the bolts in the caliper bracket, the bracket wedges into the allen bolts holding the rotor to the hub. What am I missing? thanks guys Quote Link to comment Share on other sites More sharing options...
johnzboy Posted April 30, 2013 Author Report Share Posted April 30, 2013 after looking on ebay it looks like the newer years hubs have a flush allen head bolt on the rotors.... does some one have any info on this? does it require newer rotors? newer hubs? Quote Link to comment Share on other sites More sharing options...
Starwriter Posted April 30, 2013 Report Share Posted April 30, 2013 The rotors and bolts are definitely different. The hubs are probably different. On the newer style rotors, the bolts are countersunk into the rotor. The bolts have a very low profile head and they have a shoulder that is bigger than the threads, that goes into larger bored holes in the hub. I don't have any early hubs that have the rotors off from them, but I would imagine that the early hubs don't have the larger bored holes before you get into the threads. BTW, Yamaha lists different part numbers for rotors, bolts, and hubs. (early vs. late brakes) Quote Link to comment Share on other sites More sharing options...
johnzboy Posted April 30, 2013 Author Report Share Posted April 30, 2013 NICE! frest powdered hubs and new bearings installed.... Back to the drawing board.... Thanks Quote Link to comment Share on other sites More sharing options...
Starwriter Posted May 1, 2013 Report Share Posted May 1, 2013 I'll get the rotor off one of my early hubs and see what the difference is. Maybe it just a simple matter of slightly drilling the bolt holes in the hubs. You're still gonna need late style rotors and bolts. Quote Link to comment Share on other sites More sharing options...
camatv Posted May 1, 2013 Report Share Posted May 1, 2013 mockup on unproven parts goes a long way Quote Link to comment Share on other sites More sharing options...
Starwriter Posted May 1, 2013 Report Share Posted May 1, 2013 OK, I checked it out. Other than slight cosmetic differences, the only difference between early and late hubs is the counterbored bolt holes for clearance for the shoulder bolts. It should be easy to counterbore the bolt holes in the early hubs to accept the late shoulder bolts. It would be best to do it in a drill press. In the pics below, the early parts are always on the right side of the pic. Ideally, you need a letter size X drill bit(.397"). If you can't find one, a 13/32" bit(.406") should be OK. The shoulder on the bolts is .010" smaller than the counterbored hole in the hubs, so I really don't think the counterbored hole has anything to do with the function of the bolts. Counterbore the holes 3/16" deep. It really only needs about 1/8", Yamaha did it 3/16" and you want to make sure the shoulder doesn't bottom out in the hole. Just don't drill too deep as you start losing threads. When you get the late style bolts and rotors in your hand, you will see what I am talking about. If you slightly grind a flat on the cutting edge of the drill bit, it won't dive in and spin the hub around on the drill press table. The last pic shows what I mean. This is for drilling soft metals, especially in cases where you are drilling all the way through. Quote Link to comment Share on other sites More sharing options...
johnzboy Posted May 1, 2013 Author Report Share Posted May 1, 2013 Sweet! Thanks guys! I work in a hot rod shop and we own the machine shop next door. So I will disassemble and modify as needed. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.