Choice of bearing

[Steve9]

Thanks Piemonte

That's interesting. Bought my '78 SR new, loved that bike!

And them cast wheels were heavy

[Piemonte]

All excellent points, and indeed I have already considered each.

You’ve talked me out of the track bearing. Agreed, it doesn’t feel ‘right’.

If I take 2mm off the internal face to recess the correct bearing that extra 2mm, yes the internal hub spacer will need to be shorter. I’m not sure if I will go for this extra 2mm. Today is machining day. All will be revealed soon!

The end result will be an offset hub (like quite a few bikes I can think of...Moto Guzzi? BMW rear wheels?). Visually it will be fine. Between the forks will just be all brake- plate and hub, no spacers. So it will look ‘full’ with no gawky gaps. Once machined I’ll send the brake plate and hub to an expert wheel builder for custom spokes and lacing. I’ll re-use the DID rim. Once polished it will be close enough in shine to match the standard rear chrome rim. That’s the plan.

Some of these old Japanese drum brakes are going for crazy prices. A complete Kawasaki H1 front wheel will set you back AUD$800, a Suzuki Titan in good condition around AUD$600. But the humble SR front drum brake wheel was produced in such volume that prices are still reasonable.

Thanks again for casting your eye over my calculations.

[Steve9]

Probably the same brake for the SR400. Sold in Japan-the 100 cc did a tacks thing that let them sell for less than the 500's went for by a good bit

That's what I remember anyway