Topic: Machinist question

[greenjeans]

Working on a silly XR600 project and I'm swapping the front end out for some USD Showas.  Anyway, I have to machine a bushing to fit in the upper triple as the hole in the triple is too big to use with the stem I'm swapping out.  I can make a bushing.
Most things I've read call for a steel bushing to be pressed in.  I know the ID that it needs to be.  Here's the question:  How much would you oversize/interference the bushing to press into the aluminum stem?

[J-Rod10]

.001" oversize per inch of hole diameter is the general rule for a press fit.

More importantly, before getting to that, is the hole actually round?

[754]

Is it a solid hole or has a split for clamping ?
 A thou should be fine, or size for size plus loctite... I would use aluminum.
If you need any shims under that, make a flanged bushing .

[J-Rod10]

Is it a solid hole or has a split for clamping ?
 A thou should be fine, or size for size plus loctite... I would use aluminum.
If you need any shims under that, make a flanged bushing .

I googled it when I read it. Solid hole, just a small counterbore for the nut to sit.

[greenjeans]

It's for the top clamp. Not quite as crucial as the bottom triple - that has the stem pressed in.  The XR head stock is a smaller diameter than the crf, so the stem is smaller diameter and has smaller diameter bearings.

.001" it is.  Hopefully, it's round enough.

[MikeSimon]

I wouldn't even press it in. Make a bronze bushing and slit it if the top clamp has a "clamp fit" for the stem. If the bearing is smaller, how does it fit the neck?

[greenjeans]

I purchased a stem made to fit the CRF lower clamp.  It still uses stock size bearings.  Just needs a bushing to put in the top triple to make it work.