Hi

So i have a 1998 cbr 900rr and a bunch of parts lying around to adapt a rc51 front end. well i thought i had everything i needed but it turns out my parts are all messed up. I know I have the rc51 forks the top triple from an cbr 954 and what i thought was a lower triple from an sp1 but the bearings dont work( from the 954) on the lower part of the stem... anyways im just looking to find out what lower i need in order to make this all work....

thanks

 

just a shot in the dark here, but the sp1 top bearing is the same as the 900rr as far as I can tell from the numbers- (I own a 900rr, and had an sp1 apart here) I also would look closely at the space between the races on both bikes.
uppers are the same for sp-1 and 98rr- 91015-KT8-005

the lower for the 98 900rr is 91016-KT8-005
whereas the lower for the sp-1 is 91016-MR7-003

What that tells me is that you might have to press out the stem from the lower triple, and use the 900's stem-

I'll be checking in to see how this goes for you- I'm also interested in doing this-