Front rotor (disc) dilemma, or "am I looking for something that does not exist?"

[Radradratorius]

Building a bobber, purchased the front end separately and it came in a pile of bits that look to be from different bikes. Forks look to be XS2 or TX650 (because of the speedo drive cable position I guess the pre 77 brake caliper goes to the front of the forks. Dilemma is in - what rotor (disc) do I need. At the moment I got two - 298mm OD, dished by 19mm (full measurement from outside surface to the hub), and 267mm OD, dished by 26mm. The thing is - none of them fit ! It looks like I need a 298 OD rotor, dished by 25mm. Did Yamaha make an xs650 (or any other) with that kind of rotor at the front at all? I know I could simply make a 6mm spacer for the 298 rotor, but I just have to know if there is something that would fit straight in?

 

[5twins]

Yes, there is a rotor like that. That's what came on the '76 and earlier 650s. That 267mm one you have probably came off an RD350 or something.

 

[Radradratorius]

Thanks for the reply. One more question then. What kind of fitment is it? Do they come with six holes, or does it come only like the one in this picture? Cause in that case I got completely wrong wheel for it and the only option is a spacer in the end...

 

[5twins]

That one in your pic is the real oddball among the 650 discs. It's the first year one ('72) and only works and fits on the '72 wheel. Stay away from that one if you can. All the others just bolt on using the same pattern as the ones you already have.

 

[Radradratorius]

Thanks a lot! Will be looking