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WM 20 front wheel bearings 1944 bike

The front wheel bearing seem to be hard to find and very expensive. Has anyone machined the wheel hubs to take a modern bearing? This is a 30-40 mph bike. I will use it at re-enactments, crowd control, vehicle escort. No need to anything really over 30mph.
I did searches, but found nothing.

Is this possible?
Thanks

email (option): Cbfatboyhaws@gmail.com

Re: WM 20 front wheel bearings 1944 bike

The information that I have is that the front Timkin taper bearings can be replaced with sealed ball bearings and a spacer to prevent side load.
Dimensions are:-
OD 1 3/4"
ID 5/8"
Width 13/16"

Ron

email (option): ronpier@talk21.com

Re: WM 20 front wheel bearings 1944 bike

Hello Ron,
Do I have to machine the taper out or does the spacer go on the inside. A sketch would be worth a thousand words.
Thanks
Charlie

email (option): Cbfatboyhaws@gmail.com

Re: WM 20 front wheel bearings 1944 bike

Charlie the tapers are the actual outer bearing races which must be drifted out first. then the new sealed bearings must be pressed in. A support tube of the exact distance (to be worked out) needs to be placed between the bearing inner races to stop side load. Measurements will probably need to be taken from the original set up also to arrive at the correct spacings for the forks.

Here is a rough sketch. Maybe if someone has actually done this mod they can add information. It doesn't seem too complicated to work out. Ron

Scan-20220404

email (option): ronpier@talk21.com

Re: WM 20 front wheel bearings 1944 bike

PS, here is an exploded view of the original set up. Ron

Scan-D-2

email (option): ronpier@talk21.com

Re: WM 20 front wheel bearings 1944 bike

Thanks Ron,
Total brain freeze.
I am searching for bearings that will fit the space. Got the calibers out.
Thanks again,
Charlie

email (option): Cbfatboyhaws@gmail.com

Re: WM 20 front wheel bearings 1944 bike

Well check out the sizes I posted in my first reply. Ron

email (option): ronpier@talk21.com

Re: WM 20 front wheel bearings 1944 bike

Before I get to the point of fitting my front wheel, I'll try and work out the spacer and bush sizes.
Then make a few sets just in case anyone else wants to do this conversion.

Wasn't there a post about using other size taper roller bearing with adaptors?

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

Re: WM 20 front wheel bearings 1944 bike

Modern taper rollers have been adapted to my knowledge using a pressed in “sleeve” insert & a form of lip on it to stop it falling through
So the Id on the modern replacement is larger - the sleeve bringing it back to the original m20 spindle diameter
I’ll try find the info on it or even check see if I have one 🤔

Jo’b

email (option): jonnyob1@googlemail.com

Re: WM 20 front wheel bearings 1944 bike

There is a company Vintage Bearing company in Derbyshire UK that has a modified tapered bearing with an adaptor sleeve pressed in to give sizes OD 1 3/4 ID 5/8 W 7/8. Priced at 66GBP on ebay. There part # 1178X.
It is slightly wider by 1/16, maybe the adaptor sleeve could be machined down to give the width Ron specifies 13/16.

I purchased a couple of these for the rear wheel and fitted perfect. Once you get the bearing any replacement would be easy as it is a modern bearing and simply press out the adaptor and press into the replacement.
Unfortunately I have fitted these bearings some time ago so can't give you the numbers or measurements of the modern bearing.

email (option): tknalder@iinet.net.au

Re: WM 20 front wheel bearings 1944 bike

A much cheaper solution for the rear wheel (assuming we are talking about M20s) is a 30204 metric taper bearing..These fit straight in with the only modification required being a change to the thickness of the (removable) ring that the bearing sits against inside the hub...Available from any bearing factor...I'm unsure how you fit a front wheel equivalent to the back wheel?...Ian

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

Re: WM 20 front wheel bearings 1944 bike

To add a bit more information to Ian's suggestion:- The 30204 metric bearings for the rear wheel are 0.050" (50 thou) wider than the original imperial bearings, so the removable spacer rings need to be replaced with 0.050" thinner rings which can be made from mild steel....Or 0.050" removed from the originals if you have access to a surface grinder. Ron

email (option): ronpier@talk21.com

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