This ball bearing for the front, Although I went with the modified tapered roller Draganfly sells, I never could locate a sealed ball that had a width of more than 5/8". Even one with an extended inner race was only 3/4". These would have worked with the proper spacers but I got lazy and ordered the rollers. So what is this 13/16" bearing? The BSA roller I measure at .887" wide.
Bruce those are the sizes given but I've never had to look for those bearings as I have the standard Timkins in both mine. If they're not available in that width, I guess you make the spacer to suit.
Do you know the origin of the Draganfly bearings? Ron
['Do you know the origin of the Draganfly bearings?..']
China probably, they sell lots of them...I don't rate them personally and always go for a 'branded' make but the debate around that view doesn't seem to concern most people......Ian
A couple of years ago while restoring a '52 M21 I got the rear tapered wheel bearings from Vintage Bearing Co. in Derbyshire. He sells on Ebay and lists 2 sizes for BSA 5/8 ID X 1 3/4 OD X 7/8 W and the other same except it is 9/16 id. Not sure if the WM20 has same bearings. The bearings supplied were modern ones with correct OD but a steel bush machined and pressed in to give correct dimensions for ID which was same width as original therefore not requiring any spacers or shims.
Might be worth a try if you haven't already tried him.
No special tools, just a hammer and drift behind the spacers #34. Once you have one outer bearing cup out, the second one is easier with a suitable size socket. The adjusting nuts #26/28 are left hand thread. Ron
I have managed to find replacement bearings for both wheels now. 30204 taper bearings for the rear and I will make up new spacers to suit (-0.050"). These are cheap, even best quality ones are only eight quid each.
For the front wheel I am going to convert to ball races using 1633DC bearings which are the correct size but again a different width. These are about £18.50 each as they are an Imperial bearing. Why the heck BSA in their wisdom put metric bearings in the rear wheel and Imperial in the front is beyond me. Spacers will be made to suit and a centre tube/spacer fitted to prevent side loading on the bearing centres. This will make for easy future removal should I ever wear them out which is extremely unlikely, they will outlast me I am sure.
I am sure this topic has been covered several times before but us WM20 newbies will come along and keep asking.
I also got our toolmaker to knock up a steering cup removal tool for me (1.5" bar with a 26 TPI thread) which fits perfectly.
Great website with very helpful and knowledgeable member. I will have more questions soon, when I get into the build proper. Special thanks to Ian Wright for the NOS piston rings and gearbox spacer. The third spacer he gave me the size for is already made.
Tony, bearings have been supplied from European countries from year dot (SKF Sweden for instance) I think I'm right in saying that there is a mix of Imperial and Metric inside a Norton Gearbox. I also remember something odd about the OD and ID of the main gearbox bearing in my Matchless's. I guess these firms used the most readily available or cost effective at the time. Ron
Agreed Ron, I have worked on British bikes for years and some of the things they did defy logic at times. For instance my Triumph Daytona 500 (1970). I wanted to change the handlebar bolts. I had a BSA A50 the same year 1970, the forks were the same, in fact the whole front end was the same but the BSA had different threads for the handlebar bolts ???? explain that one.
Thanks for the offer but I am an engineer of 45 years and have access to machining facilities. I have all of the bearings now and just need to make the spacers.