Page 1 of 1

Later USD triple trees on 89/90 frame

Posted: Tue Sep 01, 2020 10:03 am
by bbeen71
I am fitting the triple trees from the later 900SS on my 89 and was adviced to use the 32005/26 bearings for the swap. They do indeed work, but the bottom bearing seems to recess further into the frame than the old bearing so the lower crown is hitting the frame. Has anybody else had this problem and how did You solve it. Additional spacer under bearing cup in frame or a spacer on the triple tree, or a bit of both?

Re: Later USD triple trees on 89/90 frame

Posted: Sat Sep 05, 2020 7:20 pm
by ir_joep
Hi,

Currently I’m doing the same. I’m using the original stem pressed in the USD triple tree. That should allow the original bearings and spacers to be used. Not sure if the steering bumpers need to be removed/filed off.

Assembly is planned as the new bearings arrive somewhere next week.

Cheers Joep

Re: Later USD triple trees on 89/90 frame

Posted: Sat Sep 05, 2020 7:58 pm
by bbeen71
With the 32005/26 bearings the USD stem for fine in the frame. But will have to sort out the height of the lower bearings.

Re: Later USD triple trees on 89/90 frame

Posted: Sun Sep 06, 2020 12:59 pm
by Speedmade
I put a spacer under the lower race when I put a set of Showa forks from a 1995 900SS on a Sport

Re: Later USD triple trees on 89/90 frame

Posted: Sun Sep 06, 2020 1:06 pm
by bbeen71
Speedmade wrote:I put a spacer under the lower race when I put a set of Showa forks from a 1995 900SS on a Sport
To be sure; that means You put the spacer in the frame under the bearing race?

Re: Later USD triple trees on 89/90 frame

Posted: Mon Sep 07, 2020 3:36 pm
by ir_joep
If you use the original stem which matches the steering head, the location of the bearing part on the stem matches the locations of the bearing part in the steering head. That is of course if you use the original spacers.

I did try to use the later USD stem but could not get it it work. I tried spacers under the bearings in the steering head but ended up with the bearings not fully matching the machined parts of the stem where the bearing should sit. I felt that that was unsafe. It seems that the bearing location on a later USD stem are further apart then on the original stem, which are spaced closer.

I hope this helps.

KR Joep

Re: Later USD triple trees on 89/90 frame

Posted: Mon Sep 07, 2020 6:23 pm
by bbeen71
That makes sense. I am thinking about making some spacers underneath the bearing races in the frame and pushing them further apart. This will also move the lower crown down which I also need. If this doesnt work using the later stem is the next course of action I think ;)
Thanks

Re: Later USD triple trees on 89/90 frame

Posted: Tue Sep 15, 2020 7:27 am
by bbeen71
Well, then its on. I ended up using the stem from the 91-97. I made a spacer under the bearing race on the stem (same height as the original). I also made spacers underneath the races in the frame and discarded the original ones. 5mm if I remember correctly. Had to grind away the sterring stops as they hit the lower frame rails. Only problem now is that the fork legs hit the upper frame rails and the steering stops in the frame doesnt hit the lower crown. I will get the lower crown welded so the it will hit before the fork legs touch the frame. Also fitted the front wheel after adapting the spacers. Waiting for calipers to see what I need to fo to make room for the discs :)
Pictures when I will find energy for tiresome resizing of pictures..