What would you do? Steering bearing install

Well guys...
Me again... With one of the dumbest question ever... :pinch:
The steering bearing conversion kit I bought from ABR is great, but I'm facing a little problem right now...
I bought the kit knowing in advance that the upper bearing had a 27mm inner diameter while the ZX11 stem has a 28m diameter. I tought I could use it anyways by machining 1mm off the stem.
Today, I was checking this but I found that if I'm going to machine the stem I will lose the threaded part of the stem, and I won't do that. :dry:
How 'safe' will be to increase the inner diameter of the bearing?...
Thanks in advance!.

EDIT: Here's a pic: img505.imageshack.us/img505/6672/27544952xz6.jpg

Post edited by: Urbandrag, at: 2007/06/08 16:08

Post edited by: Urbandrag, at: 2007/06/08 16:11

Post edited by: Urbandrag, at: 2007/06/08 16:18

Seems if the stem will allow for the machining, a new set of threads could be rolled into it as well. So that means what? Getting a couple new securing parts and maybe a spacer for the upper triple tree, right?

Another option might be using the same kind of original ball bearing setup with different (mismatched) collars, using the bearing itself to clearance the difference. They come in different sizes, and I see them at Ace hardware stores occasionally.

Personally I don't think relieving a tapered bearing to obtain the kind of clearances you need is a very good idea where you're the pilot of the test ship if it fails under the kind of loading that could occur.

Thoughts of a catastrophic nose-under prevent me from agreeing that a bearing should be undercut.

I think they are hardened, unlike your body.

Cutting into that would compromise that I think.

Either or both.

Would it be possible to have the 1mm and threads turned off the stem, and have the stem tapped to take a bolt like the GPz or some KZs? Bear in mind, if you trim 1 mm off the section that fits through the upper triple clamp you're going to need a bush or sleeve to take up the slack. For my front end swap, I had to have a bushing/sleeve made to fit the stem to the triple clamp.
Or, check with a machine shop if they think they can grind out the 1mm without weakening the bearing. I had bearings ground out to fit a Honda front end on a BSA. I don't remember now how much had to come off, but it was a substantial amount, more than just a few thou - no problem.

Thanks guys for the inputs...
I asked about grinding the bearing becuase the the stock KZ750 stem nut is missing (I bougth the bare frame) and I think, I will confirm this later, also the GPz stem nut is missing...
It would be less painful (For my spare time and budget) for me to grind the bearing instead of machining a new thread in the ZX11 stem, finding a suitable nut, etc... And of course, I would prefer spend few bucks more instead of compromising safety!...
Anyways, I will visit my local machinist in a few days.

I'll keep updated.

Once again, Thanks so much!...

Update:

Today I was making some housekeeping in my workshop and I found the OEM stem nuts and dust cover from my ol' 750 turbo.
The dust cover fits OK in the KZ750E steering neck.
So, I'm going to machine the ZX11 stem to match upper bearing inner diameter and GPz stem nut thread...
Now, the question is:
What is the thread of 750 turbo stem nut?...
Hope you can help me.
Thanks in advance.

Post edited by: Urbandrag, at: 2007/06/10 14:13