Whittling down round bar stock with emery paper.

I found at a very young age that silver steel is not very good for motorcycle axles, even on a small BSA Bantam 150cc. Tended to snap on landing over jumps, which got rather exciting. SAE 4140 chrome moly steel would be my choice today. AKA EN19 I believe.

Note Jason's sage advice of turn down the whole length undersize, bar the sections where the bearings fit. Saves a lot of work.

Your piece of bar is probably the right size per its own specs. Bearing ID's are usually made to be a tightish fit on the shaft so the shaft does not spin in the bearing race. Bearing manufacturers' websites give details of exact sizing. Not unusual to have to tap the shaft into the bearing, force bearing on the inner race only of course so it does not impact the balls or rollers.

For removing a thou or two as you are attempting along a large area, if you absolutely can't turn it down, I would start with a 10" flat single-cut file such as a mill-saw file and then finish with emery. But if you follow Jason's advice and cut the area down to just the bearing mount areas, emery will probably do the job alone.

I don’t think these bearings should actually just ’slip’ along the shaft. There are fairly precise tolerances for bearing fit to shafts - usually needing to be press fitted. Yours may need loctiting if loose on the shaft.

If it's the non rotating spindle for a wheel hub then OP is correct, close sliding fit in inner, light press fit on outer. If it's the other way round, rotating inner and fixed outer then vice versa.

Edited By duncan webster on 09/05/2023 09:38:56

You cpould always put the axle into the freezer, overnight, and then fit the bearings.

The few tenths of onterference weill stop the inner race from slippingb onn the shaft, without affectingb the rest of the race too much.

Howard

Thanks everyone!

Great input and much appreciated.

As I have the Silversteel already I will do my Mk1 half-shafts in this (once I have reduced them down to allow the bearings to be a stiff slip-fit along the entire length).

Stainless Steel would probably be cheaper at any rate, but I will use what I have spent my money on already first.

Dan.

Hi Dave,

Yes I know one can buy what I am making "off-the-shelf" on Ali-Express for £100 more or less, but where's the fun in that? Geoff's "Trykit" is well known among the "English Trike" racing fraternity I think.

What I am making is a crude home-made version of Geoff's end result using mostly "off-the-shelf" sub-components, in true "Atomic-Zombie" fashion. **LINK**

Thanks,

Dan.