4 Spring Clutch advice

[MJM_58SR]

Hi all
I'm fitting a 4 spring clutch to my A10.
How far do I tighten the springs.
Is there anything I need to do when fitting the springs so as not to damage them when taking off if I need to. (Don't ask why I'm asking this question)
Any experiences would be appreciated
Thanks

[idie]

Difficult to say. You don't want the clutch to slip but if wound in to far the clutch will become heavy.

[DAVE BRADY]

Hi,

If the springs are the correct length then I would start with the stud end flush with adjuster/nut.  From here you can adjust to get the best operation of the clutch.  Make sure that the plain plates are flat and that the edges of the slots are free from wear indents.  Usually the friction plates are OK as they get replaced periodically but check the tabs and if necessary clean them up with a file - not too much but just enough to get a smooth clutch.
If it is necessary to screw the adjusters/nuts in along way to get no slip then new springs may a good idea.
It has been suggested that sliding a knife blade between the spring and adjuster so the adjuster can be slackened/undone with out damaging the little tab.

Dave.

[MJM_58SR]

Thanks Dave that's useful.
It's a new clutch being put on during a full rebuild so I'll give it a try.
Martyn

[Bess]

Hi Martyn,
                Service sheet 157 in the members area is for a 3 spring but the principles and advice is relevant:

https://www.bsaownersclub.co.uk/members_area/get_serv.php?sheet=SS153

Best wishes...

[Mike Farmer]

 

A thought. What springs are you putting in. The original A10 springs were 38mm---the best I could get after market are 42/43mm,

However KMC have (had) some NOS 38mm.

So even with A50/65 4 spring which I understand had 38mm springs, I use the A10 springs.

I think much easier to fit and adjust and an easier action. I havent had a slippage problem to date.

Mike

[MJM_58SR]

Hi Mike
The clutch is a KMC clutch. I'm pretty sure the springs are 49mm but I will recheck. I've got a set of SRM springs that are the same size, these are a replacement set for the damaged ones (I'll put on as a set) but it does seem very tight getting them on. Part number I'm using is 57-1560 or that's what they are advertised as.
I'll call KMC and ask about the 38 mm ones but 10 mm difference seems to be more than a bit of an error!
Martyn

[Mike Farmer]

 

Sorry that was for the original clutch, KMC is going to be different so sensibly ignore my previous. Its snowing here.

Mike

[Nanonevol]

I recall having a difficult time finding the correct springs for my 4 spring.  Some vendors have the wrong item.  One finally sent me a set that were cut and filed to size.  They did work.
Sorry I don't recall more details.  Must start taking notes.  You may need to experiment to find what works.

[Mike Farmer]

 

Going back to my post on this. My thoughts are that the original 4 spring A50/65 used the A10/7 springs. Thats what I have in my A50 and they are fine. No problem fitting or adjusting.

I've also gone down the cut and file line. seems ok except===if you do that ensure that you fit them cut end first. If you have the cut end outward they are very likely to jam when you try to remove them. Please don't ask me to explain the source of my knowledge. 

Mike

[MJM_58SR]

Thanks Mike
I've got another set of springs from SRM and I'm heading into the garage this afternoon to try and fit it up.
Did you torque your hub nut up or just tight?

[DAVE BRADY]

Hi,

The clutch nut needs to be very tight.  The A65 manual says 70/65 ft/lbs of torque so the A10 will be about the same.  It is also worth lapping the clutch centre on the shaft.  The grip on the taper is as important than the key. 
Use some fine grinding paste and ensure an even light grey colour.  Make sure it is all cleaned off really well.  On fitting the centre tap it quite sharply to help it to seat on the taper.  If the fit is good it will not easily pull off again by hand and the high torque on the nut will ensure a solid and reliable fit.   The last thing you want is your nice new clutch to come loose on the taper and damage both faces as well as leave you stranded.

Dave.

[Mike Farmer]

 

Hi

Torqued to 70lbs.

Mike

[MJM_58SR]

Thanks all
All torqued up to 70ftlbs now and all good