The bearing race is hardened and is pressed into the chain wheel..They would probably have been ground to size after fitting...

I think the easiest and probably cheapest solution would be to source oversize 1/4" x 1/4" rollers and then have the races honed to the new size, a pretty straight forward process....Ian

email (option): ian@wright52.plus.com

Hi Ian
Yes I had thought that if oversize rollers were available it would simplify things
I’ll start making enquiries with a bearing supplier
Br
Jo’b

email (option): jonnyob1@googlemail.com

Vintage Bearings at Derby keep some roller sizes in one thou oversize increments. I got some +2 thou 1/4x1/4for a Sturmey Archer clutch and they did the trick.

I wonder, is this bearing really so important ?
It only works if you pull the clutch, so when the enginepower is "off" ?

A complete clutch is something I will be looking for at some point. Honing such a short blind bore might be a pain to do. Hard turning might be better, but it all adds to the price.

email (option): pes.sales@btconnect.com

Hi
If I sourced oversize bearings could this hardened surface be skimmed on a lathe ?
Br
Jo’b

email (option): jonnyob1@googlemail.com

With the right tooling.

email (option): pes.sales@btconnect.com