Cush drive "nut" fixing

[Jules]

I've been reading up on old threads regarding the cush drive nut and the importance of getting it "bloody tight" and have decided that while I'm contemplating a change to the engine sprocket, that I should also upgrade the torque/tightening methodology for the cush drive nut (hammer and brass drift in the past  )........
I've just looked at the SRM nut and some old threads suggest that its thread is a bit "ïffy" and its now 33 GBP plus a considerable postage, so maybe I'll just go for the Peugeot ball joint adaptor nut that has been suggested earlier. There are a few available on Ebay but I wanted to check in to see if there is a particular one to use please eg Sealey manufacturer comes up often? best prices are around 16 GBP plus around 8 GBP postage - wot say you guys?? thanks

[Colsbeeza]

Jules, Swarfy has the answer. I had no trouble fitting to my 1961 S/A. Does SRM make one for the plunger?

https://www.a7a10.net/forum/index.php?topic=16330.msg139598#msg139598

Col

[JulianS]

Had the SRM nut on my swinging arm A10 for years, no problems. I use a long ring spanner to tighten it and use thread locker.

The ball joint spanner needs the original nut to be undamaged otherwise it will not fit. I took the photo below some 8 years ago with a new old stock nut and Laser make socket and it shows the fit is very close. It takes a 35mm socket.

[RichardL]

For the sake of not spreading unfounded rumors from those disgruntled with SRM for whatever reasons and are unnamed on unnamed sites, I think I’ll just call bullsh*t on the “iffy” threads. I have two, one since they first released them and one from a couple of yeas ago, and the threads are fine. It is much more likely that crank threads are damaged, thus causing a rough fit. Mounting holes for a timing disk are a side benefit.

Richard L.

[groily]

Ain't that the truth, as I found when cobbling up a weapon of my own to use on a not-pristine nut. Did the job though, and it was easy to get 65 or whatever lbs ft on it.  I'm sure the SRM job is a big improvement though.

[Billybream]

I,ve got the SRM, been fitted now for 5 or 6 years, just had the primary cover off to change the chain and still rock solid

[berger]

jules i like it , hammer and brass drift , proper fitter , when you hear that solid sound you know it's good

[Worty]

Word of warning fellas.  I bought a new, original type nut and the Peugeot tool off Evilbay.  The tool fitted the knackered nut fine, but the tangs of the tool did not fit the new nut (too tight).   I spent about two hours filing the gaps in the nut to get it to a nice snug fit.   I then discovered that the tool was about 34.5mm, so I couldn't get a 34mm on it, didn't have a 35, but a 36 held it just enough for me to belt it up (I now have a massive adjustable spanner to do the job).   After fitting with plenty of Loctite, I used a large hammer and (sorry) steel drift to nip it up to the 'dull thud' stage (no brass drift).  Nut was undamaged and has not shifted since.

Don't know about you guys, but a 35mm socket doesn't seem a common size in larger sets.  I have a 3/4" set with sockets up to 46mm, but all even sizes.

[sean]

I have the SRM nut ....no problems at least able to get a torque wrench on it

[muskrat]

G'day Jules.
I have a foot in both camps, SRM on the Cafe and standard on the plunger and use the Peugeot tool off Evilbay. Both fit and work well.
You'd be quite welcome to borrow my Peugeot tool, not the sort of job I do regularly.
Cheers

[Colsbeeza]

Jules, I still have my Peugeot tool. I won't be going back to the BSA nut. Musky can keep his - I'd bet the day you borrow it he would want to use it. You can have if you want. PM me for address.
Col

[limeyrob]

I've junked the BSA nut and gone for the SRM nut.  One seldom mentioned benefit of the SRM nut is that it does no include the perfectly sharp gutting teeth to drill out the chain case in an instant.  I've never seen a chain case that's not at least 50% cut through.

[Jules]

I agree with your observations Rob, when I was looking for another chaincase there were lots that were "machined" inside. In my case it was the clutch though and the case had been (poorly) welded because it had actually gone through the case!!

[Jules]

thanks for the offer Musky, appreciated....Col has a plan to get his no longer needed one down to me though...

[sean]

I've junked the BSA nut and gone for the SRM nut.  One seldom mentioned benefit of the SRM nut is that it does no include the perfectly sharp gutting teeth to drill out the chain case in an instant.  I've never seen a chain case that's not at least 50% cut through.

Another benefit is the extra drilled and tapped holes to mount a timing disc to the nut.