AJS & Matchless Owners Club

I have been helping a fellow member who is not an internet user with the clutch on his recently purchased 1937 Model X. He felt that the clutch was heavy compared to the Burman clutch of his early 50's single fitted with the B52 box. We dismantled the Model X clutch and replaced the clutch springs and plates for the correct items from AMC Classic Spares.

There is something odd with the clutch. According to the 1937 parts list from Christian's archives, there should be 4 friction plates and 4 thin steels, this Model X has 5 of each. It has the correct 12 5/8" pushrod and a 4 spring pressure plate. If the correct number of plates per the book are fitted the clutch does not grip at all, but with 5 it functions, although the handlebar pull is heavier than any Burman clutch I've tried on AMC, Vincent or Ariels. I suspect that it may have the wrong pressure plate and the extra friction and plain plates are taking up the gap. I'm not sure this explains the heavier feel.

Can anyone help with suggestions to make the handlebar pull lighter without the clutch slipping?

Thanks

Alan

Alan, Check the parts list again. It reads 4. thin plates, 4. friction plates and 1. thick steel plate.
The thick steel plate goes on first, followed by friction plate, thin steel plate and so on ( 4 of each )
As you have no thick steel plate, but an extra thin steel & friction plate.
These two would be thicker than the thick steel plate, so may make the clutch feel heavy.

Thanks Rob, The thick plate is in the clutch at the back as you suggest and it still has the 5 friction and thin steel plates.

Alan

Just idle thoughts.......
Could there be an extra and unnecessary ball (1.) (or two) in place which is in effect lengthening the otherwise correct length pushrod?
Does the clutch grip o.k. with the 4+4 plates setup if you remove the pressure plate centre stud (2)?

There is a thrust rod sleeve adjusting screw also (3.).
EDIT
Ah, if it's the CP 'box I am a bit familiar with it. However, if you haven't already seen it there's info and illustrations (including comments on clutch slip) on pages 128 to 130 of the Workshop Manual here:
http://archives.jampot.dk/book/Workshop ... dition.pdf

Here's one of the illustrations:

Know nothing about the Model x but would extra plates make the clutch feel heavier at the handlebar? I would have thought the more likely issue is the lever. Are they original? It has often come up on the forum that levers with an inch between fulcrum and cable will feel heavier than 7/8 ones. (Or is it the other way round?) I have never got round to measuring mine. I have noticed however that some pattern ones wear at the pivot point pretty quickly. Might this be part of the trouble.

clive wrote: ↑Mon Apr 26, 2021 9:58 pm It has often come up on the forum that levers with an inch between fulcrum and cable will feel heavier than 7/8 ones. (Or is it the other way round?)

Correct lever is 7/8" between cable nipple centre and the centre of lever pivot bolt.

.....would extra plates make the clutch feel heavier at the handlebar?

I'm visualising that with the extra plates the four pressure springs would have to be be pretty squashed up (shortened) in order to get the spring pressure nuts to start on their bolts and the springs might even become coil bound when the h/bar lever is operated causing a very heavy action.

I prefer a book closer to the year of the bike the 1939 edition may have more info than a 47 edition.
http://archives.jampot.dk/book/Workshop ... .Neill.pdf
I assume the trust rod is clean, straight and not seizing.

Thanks everyone, a few more things to check. The clutch operating mechanism appears complete including the ball bearing, that I know can often be missing. There is no grip at all with the 4 friction and thin steel plates plus the thick plate at the back. I think that the extra plates are filling a gap, but what has caused the gap I don't know. The Model X has a BAP gearbox, could a 4 plate post war CP clutch be fitted with 5 springs rather than 4?

I will check the handlebar lever and the cable routing in case it is binding somewhere. I could cope with the current set-up but my friend is older and has a smaller hand span than me and feels he will struggle with things as they are.

http://archives.jampot.dk/technical/Tra ... alogue.pdf
The BAP box is correct for model X.
Above is the parts list for BAP note P = pivot mounting. You will only see BAP in the parts list for parts that are BAP only.
Maybe you have the wrong clutch. You may need longer pins cups ???? Have a word with Pat Gill he may be aware of what may have been used on your 37X.
matchlesspat@aol.com