I have a '69 cl450 and I want to replace its front end with a '79 xs650 unit (ill be using the xs650 hub as well). I know All Balls makes the bearings I need to fit the stem into the 450 neck, but there is about 1.5cm difference in neck length. Can I just get a spacer to make up the difference? What are the issues I'm overlooking here? Thanks!
cl450 with a xs650 front end conversion question
- Thread starter DHolbrook
- Start date
First off, that's CM not MM 
Yes, you can put a spacer under the two locking nuts on the XS650 stem to cover the extra distance between them and the top bearing. BUT, the real issue is will the top bearing sit low enough to mate with the race in the frame? The XS650 stem tapers and gets thicker as you move down, and the top bearing will only go down so far.
I think you'll be OK - 1.5cm isn't much and I think the XS650 stem will allow the top bearing to slide down that much extra but you should confirm.
Yes, you can put a spacer under the two locking nuts on the XS650 stem to cover the extra distance between them and the top bearing. BUT, the real issue is will the top bearing sit low enough to mate with the race in the frame? The XS650 stem tapers and gets thicker as you move down, and the top bearing will only go down so far.
I think you'll be OK - 1.5cm isn't much and I think the XS650 stem will allow the top bearing to slide down that much extra but you should confirm.
OK so I need a spacer that's about 2cm length to make up the differences between the stems. Looking around McMaster Carr, most of their spacers that size (30mmID x 40mmOD) are plastic. Then I remember that my fork tubes have a PVC spacer in them, so..... can I use PVC as a stem spacer too?
Tim said:First off, that's CM not MM
Yes, you can put a spacer under the two locking nuts on the XS650 stem to cover the extra distance between them and the top bearing. BUT, the real issue is will the top bearing sit low enough to mate with the race in the frame? The XS650 stem tapers and gets thicker as you move down, and the top bearing will only go down so far.
I think you'll be OK - 1.5cm isn't much and I think the XS650 stem will allow the top bearing to slide down that much extra but you should confirm.
Ok I need some help please...this shouldn't be as complicated as I'm making it.
The bottom bearing looks great, a few taps and it will seat where it should. There is no room for a spacer under the bearing though; the machined surface is not big enough.
I need to essentially shorten up the stem length about 15mm. the upper bearing won't sit low enough for it to meet the race in the neck.
Questions
Is the upper bearing supposed to sit on the lip of the machined area of the stem?
I have another upper bearing with a slightly larger ID (same OD) that gets it over the lip and sits where I want it to. (see pic) There is a little play between this bearing and the stem. How much play is acceptable?
Is there a way I can make this work? Do I need to have the machined lip lowered to where I need it, or have the stem cut in the middle and welded shorter? I guess I could exchange the necks by pressing them out, but that seems the most costly. What's my best option here?
Thanks again!
Attachments
No play is acceptable in bearings.
So, your best bet is to have the stem turned on a lathe to extend the seating area for the top bearing down a bit to allow it to mate with the race in the frame.
Then, you need a solid steel structure (i.e. a stack of thick washers or more likely, have the person who turns the stem for you make you a spacer that is the same outer diameter as the locking nuts that thread onto the stem) to cover the extra distance between the locking nuts and the top bearing.
That's that. Swapping front ends is never dead-simple.
The most simple solution is to have the stock steering stem swapped into the XS650 trees. Worst case you might have to deal with the very top of the stem where the top tree sits on it if the two stems are different diameters up in that area. That's the typical route and most simple - swapping stems.
So, your best bet is to have the stem turned on a lathe to extend the seating area for the top bearing down a bit to allow it to mate with the race in the frame.
Then, you need a solid steel structure (i.e. a stack of thick washers or more likely, have the person who turns the stem for you make you a spacer that is the same outer diameter as the locking nuts that thread onto the stem) to cover the extra distance between the locking nuts and the top bearing.
That's that. Swapping front ends is never dead-simple.
The most simple solution is to have the stock steering stem swapped into the XS650 trees. Worst case you might have to deal with the very top of the stem where the top tree sits on it if the two stems are different diameters up in that area. That's the typical route and most simple - swapping stems.