I've been changing the engine sprocket on the 1948 B32 Competition and found the crank nut on the shock absorber to be in pretty poor condition.I have another but isn't so thick, about 3-4mm less. To confuse things further, the nut I took off had 2 thick washers under it which I'm sure shouldn't be there.
The pic shows the the one that was fitted on the right, along with the washers. The one on the left is what I want to fit - with the washers maybe?
Any one know which should be there?
You can't always tell from the parts book but it certainly looks as though it should be the thicker one. There doesn't look to be any plain washers fitted.
I have an assortment of sprockets and shock absorber parts, both 4 lobe and 2 lobe. The one on the bike is a 4 lobe but I think the thinner nut is from a 2 lobe assembly. I would fit a 2 lobe shock absorber and sprockets but that would give an alignment issue so I'm staying with the 4 lobe assembly but would prefer to use the thinner nut, possibly with the washers under it so the spring isn't over compressed.
That sounds about right!
When I changed the 4 lobe arrangement for the 2 lobe on my 1949 M33 I found no problems with the chain alignment. I must say I have never seen a nut like the one on the right.
All the 1948 models except the A7 used nut 65 2520, which was in use for many years on the singles ncluding on the DBD Gold Stars.
The nut on the left looks like 65 2520, the one on the left who knows.
Photo show a new old stock 65 2520, regret shown with the tool but you can see what it is like.
Quote from: JulianS on 15 Jan, 2022, 21:02
All the 1948 models except the A7 used nut 65 2520, which was in use for many years on the singles ncluding on the DBD Gold Stars.
The nut on the left looks like 65 2520, the one on the left who knows.
Photo show a new old stock 65 2520, regret shown with the tool but you can see what it is like.
The tool looks interesting Julian. I had a devil of a job getting the nut on and off my 1949 B31.
Is it a tool that's available to buy or is it one you made?
Pete
It is a lower ball joint socket for a Peugot 405 and some Citroens. Available on ebay from various sellers.
It is a snug fit and will not go on it the nut has got burrs from use of a drift. It takes a 35mm spanner or socket.
Hi,
Is the SRM cushdrive nut suitable for this model? I have fitted one on a '51 Flash and the hex head make fitting and tightening much easier.
Dave.
Quote from: JulianS on 16 Jan, 2022, 11:29
It is a lower ball joint socket for a Peugot 405 and some Citroens. Available on ebay from various sellers.
It is a snug fit and will not go on it the nut has got burrs from use of a drift. It takes a 35mm spanner or socket.
Cool, thanks Julian
Quote from: DAVE BRADY on 16 Jan, 2022, 12:30
Hi,
Is the SRM cushdrive nut suitable for this model? I have fitted one on a '51 Flash and the hex head make fitting and tightening much easier.
Dave.
If it is I'd recommend getting one; It makes working on the shock absorber a doddle. By coincidence I've been checking the timing of my A10 (to save further embarrasment trying to start the bike when leaving friends in North Lincs ;))and the SRM nut also takes their easy fit timing disc.
Thanks for all your replies. It seems that the 65-2520 nut was fitted to all the singles. But through the parts lists shows that there were 4 different nuts used on the twins, so the nut on the right of the picture could be one of those.
And thanks to Julian S for the tip about the Peugeot ball joint socket. I've ordered one.