Just thought I’d give a ‘shout out’ for a helpful manufacturer/supplier.
I recently purchased a pair of sealed headstock bearings from one of the big suppliers. The bearings are good quality Timken items. They have an inner race bore of 25mm diameter. I ordered a new stainless steel bearing adjuster nut from ‘Triton Cafe Racer Parts’ after having had problems with the nuts from the ‘big’ suppliers. When I received it, the diameter of the collar that fits into the bearing was 25.4mm - that’s the standard size that he makes them. Normally that would mean yet another ‘problem purchase’ requiring a hunt for another supplier. However, Steve at Triton Cafe Racer Parts was really helpful and made me a new nut to exactly the dimensions I needed. It fits perfectly and has a really high quality finish.
I just thought I’d mention this in case anyone else goes the Timken sealed bearing route and looks to buy a stainless bearing adjuster nut that fits. I have no connection with Triton Cafe Racer Parts apart from being a very satisfied customer.
Hi Edward. I got my bearings from RGM and from what I remember, the dimensions are as you have stated. The top bearing sits about 0.5mm above the headstock tube. I’ve not fully built up the front end yet but I’ve got both yokes fitted and the bearings adjusted - they are absolutely fine. I’ve got the dust cover under the adjuster nut but I didn’t put a felt washer underneath the dust cover as that seemed to cause a bit of binding and movement restriction when the adjuster nut was done up to remove the up/down play.
Hope that helps