Neck bearing swap problems

gijoe13844

gijoe13844

Coast to Coast
Trying to get the buell thunderbolt front end on the 79 xs11 frame.

Buell stem OD is 25.4mm or 1 inch.

Xs neck top race mount ID is 47mm, lower is 55mm, widths are 11mm and 16mm respectively.

so my top bearing needs to be
25.4/47/11
bottom
25.4/55/16

problem is that neither allballsracing or McMaster carries anything in that size.

im thinking my option may be to either turn the stem down or machine a bushing that fits in the neck....or both.

Any other thoughts?
 
Does the stem press out of the bottom triple? If so, turning it down to 25mm would be the easiest and most solid option.
 
hillsy said:
Does the stem press out of the bottom triple? If so, turning it down to 25mm would be the easiest and most solid option.
Click to expand...

It does press out. That helps me on the top as all balls has a 25/47/13 I believe, unfortunately, it doesn't fix my lower issue. I'm thinking turn it down to 25 then make a bushing to get the lower from 55mm 52 or 47 even.
 
Or a bushing for the stem at the bottom to make it 30mm. 30x55x17 is a common bearing size.
 
hillsy said:
Or a bushing for the stem at the bottom to make it 30mm. 30x55x17 is a common bearing size.
Click to expand...

That would be a much easier bushing to make, I could probably machine a 1mm lip in the stem (24mm) to press seat the bushing on...I like that idea.
 
For future reference, the XS stem is only minimally welded. Grind that bead off the bottom, and the stem will pop right out.

Also, you could have a neck made by a machinest. May be cost prohibitive, but... It's an option.
 
VonYinzer said:
For future reference, the XS stem is only minimally welded. Grind that bead off the bottom, and the stem will pop right out.

Also, you could have a neck made by a machinest. May be cost prohibitive, but... It's an option.
Click to expand...

Well I actually am a machinist (mainly cnc but can run a lathe when needed) but I am trying to avoid having to make my own stem. For threading reasons, don't want to buy the right die :)

I think what I'm going to do is make two bushings that brings my stem to 30mm

Then I can go

30/47/12 and 30/55/17... Both are sizes all balls carries.
 
You'd be better off leaving the top stem at 25mm - 25x47 is a real common bearing too (in fact, you already have one ;) ).
 
hillsy said:
You'd be better off leaving the top stem at 25mm - 25x47 is a real common bearing too (in fact, you already have one ;) ).
Click to expand...

I would except 25/47/12 is not common, all balls only has a 25/47/15...
 
Have you measured the stem length of the Buell v the Yamaha? If the Buell is longer, then a taller bearing wont be a problem.
 
Stem length is about 1 inch loungers I need to turn it down...but I don't think I want the bearing sticking out the top of the neck that far do I? (Almost 4mm)
 
How deep is the race recess in the XS neck? Most of them are a few mm deeper than the race height.
 
hillsy said:
How deep is the race recess in the XS neck? Most of them are a few mm deeper than the race height.
Click to expand...
The cavity that the top race sat in is 11.5mm deep. Bottom was 16.5.
 
That's pretty shallow actually.....

I'd say the race on a 17mm height bearing would be around 13-14mm. That's still a lot of race in the neck. The OEM XS cover should still hide that, too.
 
Sounds like you need to make a bushing with a lip in order to use a more common size bearing. It won't change the physical characteristics of how the bearing performs, which is a plus, but you need to make sure that the fit is absolutely perfect. Don't want any sloppiness in the steering...
 
Well I think I figured out the front end conversion. Took way longer than it should have but putting a Harley front end on a metric bike is a bitch.

IMG_20140311_173610_875_zps963d0afe.jpg

IMG_20140311_183058_658_zps1c4d6291.jpg

IMG_20140311_183104_872_zps02c09346.jpg


fit perfectly when all was done.
 
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