As i have always used what was at hand, I've only ever used six spring clutch's I'v never used a single spring clutch until we fitted one today. Is it usual to be a gorilla to use these things? After the nightmare of starting the clutch nut and testing the action seems to be miles too much tension.Is this usual/ And what does the factory tool look like for engaging and disengaging said nut? Tried a search but can't find anything?

Hi Doug,
I have been mucking around with the single spring clutch on my project. I have found that there is a happy medium for spring tension. in the workshop manual it says to tighten the nut to the max, however when this is not its near impossible to release the plates. So I have experimented with letting off tension another so I can kick the bike over yet still use the clutch. In relation to the tool to engage the clutch nut I bought one off Bill Green here in Austrialia. however the tool would not be hard to make its jus a 4" blot which runs through a metal disic that covers the clutch spring nut and a hexagon nut that fits the bolt that screws tension down on the disic. You screw the bolt into the clutch centre nut then tension the couch nut and spring down then use a tool that turns the nut, also a tool a got from Bill Green. Sorry I have not got pics.

email (option): banderson323@bigpond.com

Doug,
Have a look at the Technical Info page on the website, "Clutch Tool"
Hans

email (option): viaconsu [at] planet [dot] nl

The operation of the single spring clutch should not be overly heavy even when fully tightened. Not tightening the clutch spring nut all the way home and then 'knocking it up' against the end of the clutch centre will result in it coming completely undone during operation....If it is decided to lighten the pressure on the spring a spacer of the required thickness should be fitted behind the nut so that it is still fully tightened when fitted. This should not be necessary though and will reduce the amount of the clutch nuts thread engagement.
Check you have the correct spring...it should be 2 3/8" long when new...
Also check the pushrod is free in the mainshaft and that all the metal plates move freely within the clutch sprocket and on the clutch centre...Any 'notches' that have been worn into either the sprocket or centre can cause the plates to 'snag', restricting movement, and should be removed with a smooth file if not too deep...
Also check the routing of the clutch cable, ensuring it runs smoothly from the bars to the box without sharp turns and that it is well lubricated....
Finally, ensure the clutch is correctly adjusted...There is some clutch related information on the 'technical section' of the website....Ian

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

Hi Douglas

I have used a tool made by rob Nortier on my clutch, it works well for assembly & disassembly

I also got a tool, similar in construction from another forum member in holland, it makes the assembly & disassembly a lot more civilised

I think Ron pier has some of Robs kit for sale

Best regards

Job

email (option): Jonnyob1@googlemail.com

Had another play with it today. The only way was unwinding the spring nut 1/4 inch and put a spacer behind it so as to lock it up properly. I's a lot better now but still tough even with 2 less plates. We have two springs to play with but they are the same length. Don't know how any of you get their's light.I think the springs are overkill.Maybe someone could get some softer springs made up. they might sell like hotcakes?

I have a standard spring and two plates removed. No spacer and nut locked up tight and it's light as a feather!! I have not run my cable under the tank as it creates too many turns, rather the more direct route.
Ron

email (option): ronpier@talk21.com

What you have is not normal Douglas...there is something wrong somewhere that is making the clutch so heavy. I route the cable in a similar way to Ron...Ian

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

I have some tools on order from Rob but he seems to have vanished.
I do hope he is well & it is just an internet problem.

So for the time being I assemble & dissasemble my clutch using my drill press then fit it to the bike as a complete unit

email (option): wariron@tpg.com.au

Maybe someone can send in a picture of an original spring to compare?

Hi Douglas..The spring is of the same form (but not the same dimensions) as a crankshaft shock absorber spring..i.e. Wound from oblong (flat) section spring steel..See my previous post detailing the standard length....Ian

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

So Ian, would that mean it is possible to fit a cush drive spring to the clutch by mistake?

Ron

email (option): ronpier@talk21.com

I haven't tried!...The cush drive spring is quite a bit shorter and also a smaller diameter so it may not be possible to get one into the clutch. The other way round would make fitting the crank nut..errr..difficult..and it would probably be coil bound when tightened...Ian

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

Ron

Thank you for posting the photo attached to this post it has solved my problem with fitting the rear brake lever


Cheers

Ron FTLDU

email (option): Grumpy.moran@gmail.com

One thing I didn't mention was I'm using this clutch on a plunger style box. Maybe the leverage for the clutch arm is different? Maybe the WM box has a longer lever? We have fitted a BB34 engine into a B31 rigid frame.

Douglas I know nothing about post war box's. Ian will know I'm sure. But here are the correct springs which are 2 1/4" diam. Ian has already stated the length. Ron

email (option): ronpier@talk21.com

I have an earlier type BSA single spring clutch from about 1936 which you don't wind the nut up against anything & alot of what I've read here keeps making me wonder if its this earlier type which is recognized by only having 4 nuts/Studs holding the pressure plate on.

not wishing to add confusion ...but its another possibility.