Author Topic: 6 spring clutch locking nut question.  (Read 250 times)

Offline Hughsie

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6 spring clutch locking nut question.
« on: 24.07. 2022 20:04 »
Evening All.
So I've been out for a couple of short test rides following years of getting my A7 project on the road, and selecting neutral was impossible.
So I've spend a few hours reading many posts on clutches etc. (Yes I want a 4 spring conversion,  but that needs to wait)
I've opened up the primary cover to find a 6 spring clutch lurking. So I've spent a few hours setting up the springs to try and help the plate lift off more square.
I noticed I have double locking nuts, is this usual?
I feel I would like to back the springs off a little more but I need to set the locking nut at the end.
I've not checked for clutch slip yet but I noticed nylock nuts are available online.
Currently it's now lifting much more evenly but still very heavy at the lever.
Any thoughts on these locking nuts?
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Online RDfella

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Re: 6 spring clutch locking nut question.
« Reply #1 on: 24.07. 2022 20:24 »
My locking nuts are near the end of the threads and clutch is not heavy (but does slip when it has oil on it).
About the only way to ensure the clutch plate is lifting squarely is to cable-tie the clutch lever so outer plate is lifted free, and watch it (preferably with a dial gauge) whilst using the kickstart to turn it over.
Also, before every ride, use kickstart lever with clutch lever pulled in to un-stick clutch plates. That way you'll get a crunch-free engagement of first. Selecting neutral is always a bit his/miss - I usually select it just before I stop or by hand if already stopped.

PS - that primary chain looks a wee bit tight - does it have slack all the way when rotating engine?
'49 B31, '49 M21, '53 DOT, '58 Flash, '62 Flash special, '00 Firestorm, Weslake sprint bike.

Online slighthitchmitch

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Re: 6 spring clutch locking nut question.
« Reply #2 on: 24.07. 2022 20:32 »
Get bigger hands.

Check your handlebar lever pivots are not worn, lube them.

Check you have a nice cable run with a quality cable, lube it.

Check the pivot arm on the gearbox doesn't need new bushes, grease it.

Remove your clutch pushrod and lick it until it shines, oil it.

Take your clutch off and throw it in the river,  ha ha no.

Do those things first, then make sure your plates are nice and flat and clean and yeah, pay attention to your plate lifting and turning square.

I wouldn't worry too much about having the locknuts as long as you have original springs fitted, take them out and make sure that they all are the correct length and are not mis-shapen in any way.

I used to be able to pull my A10 6 spring clutch lever with 2 fingers.

Seriously, a lot of the effort is upstream of the clutch itself, make sure the pivot lever on the gearbox is at 90 deg. for max. efficiency, for example.

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Offline Hughsie

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Re: 6 spring clutch locking nut question.
« Reply #3 on: 24.07. 2022 21:51 »
My locking nuts are near the end of the threads and clutch is not heavy (but does slip when it has oil on it).
About the only way to ensure the clutch plate is lifting squarely is to cable-tie the clutch lever so outer plate is lifted free, and watch it (preferably with a dial gauge) whilst using the kickstart to turn it over.
Also, before every ride, use kickstart lever with clutch lever pulled in to un-stick clutch plates. That way you'll get a crunch-free engagement of first. Selecting neutral is always a bit his/miss - I usually select it just before I stop or by hand if already stopped.

PS - that primary chain looks a wee bit tight - does it have slack all the way when rotating engine?

Many thanks, it was all very tight and plate was lifting to one side, so I've deffo improved things.
Yes a little play in chain, but its on my list to do as like you've noticed, I think it needs more slack!
Thanks for highlighting this as its a good spot!
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Offline Hughsie

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Re: 6 spring clutch locking nut question.
« Reply #4 on: 24.07. 2022 21:53 »
Get bigger hands.

Check your handlebar lever pivots are not worn, lube them.

Check you have a nice cable run with a quality cable, lube it.

Check the pivot arm on the gearbox doesn't need new bushes, grease it.

Remove your clutch pushrod and lick it until it shines, oil it.

Take your clutch off and throw it in the river,  ha ha no.

Do those things first, then make sure your plates are nice and flat and clean and yeah, pay attention to your plate lifting and turning square.

I wouldn't worry too much about having the locknuts as long as you have original springs fitted, take them out and make sure that they all are the correct length and are not mis-shapen in any way.

I used to be able to pull my A10 6 spring clutch lever with 2 fingers.

Seriously, a lot of the effort is upstream of the clutch itself, make sure the pivot lever on the gearbox is at 90 deg. for max. efficiency, for example.


Some great points to work though, thanks for this. All except the bigger hands, that is something that would probably be helpful, but I think I'm a distant relative to Jeremy beadle. ✋️
I didnt know you could adjust the gear box pivot lever, I will check this also.  Many thanks.
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Offline BSA_54A10

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Re: 6 spring clutch locking nut question.
« Reply #5 on: 25.07. 2022 05:02 »
The factory instructions are for setting the clutch so you could pull a double adult side car with 4 kids & camping gear in it and deavily pregnant mum on the back without slipping .
IT is way too tight
put the front wheel against a wall so the bike can not move
Put the bike in top & attempt to kick it
Back the adjuster off 1 falt a time till the kickstarter just slips then tighten all of them 1/2 turn
You will find the clutch sooooo much lighter to use
A lighter clutch is easier on your wrist but more importntly easier on the pivot & lever so they don't flog out any where near as quickly .
Bike Beesa
Trevor

Offline Slymo

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Re: 6 spring clutch locking nut question.
« Reply #6 on: 26.07. 2022 02:48 »
That primary chain looks rather tight? Make sure the cover plate slides on nicely without binding. I assembled my six spring with the aid of a copper hammer in order to get it so the clutch basket allowed the plates to slide in nicely then the cover plate to go on without binding. It seems counterintuitive but the smallest amount of friction between plates and basket has a very negative effect on the clutch both in terms of slippage and lever weight. I believe there are two depths of spring cup which will make a difference as to where the lock nut sits and yes you definitely need two nuts (no smirking Jenkins). I generally set the tension up by eye and have proven with a dti that I'm not too far out. I set it up so that I can spin the centre with the clutch lever pulled and the bike in neutral then slowly release until it takes up. If it takes up too soon before the lever is slack then its likely taking up unevenly. The centre should spin easily with the clutch lever pulled. Any resistance and you are going to have an issue finding neutral especially at the lights. Good luck and stick with the six spring. It is original equipment and perfectly good when sufficiently fettled.
NZ

Offline Swarfcut

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Re: 6 spring clutch locking nut question.
« Reply #7 on: 26.07. 2022 07:32 »
 This infernal device strikes again. When Slymo mentioned the cover plate and a hammer, that threw me. On reflection I think we're talking pressure plate, and the use of a hammer to re-align the clutch basket fingers. Particularly on a used item that some miscreant has dropped, kicked and thrown against something substantial in a fit of frustration.

 The other major problem with used baskets is the inevitable wear to the fingers,  in the form of slots which will restrict the driving plates' movement as they lift, hence the inevitable clutch drag and hard to find/missing neutral. As mentioned, old hands free the clutch before starting up, and snick into neutral just as coming to rest. When new I reckon it would work fine, but BSA's almost universal clutch does not age well. But I'll agree with Slymo, set up properly they're OK and worth taking the time to examine every part, as all these little defects and imperfections add up.

  The basic design was used across the whole model range, so correctly fitting but incorrect parts for a particular model are a potential minefield. A 6 Spring clutch complete from the C range will fit a Super Rocket, but it will slip a bit......

 Adding extra plain plates and well worn ("thinner") lined plates were another old trick to increase spring tension and friction capacity, back when the new bits were scarce/pricey. Looks like room for another plate, I have found that pattern plain and lined plates can be considerably thinner than the originals.

 Swarfy.

Offline Slymo

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Re: 6 spring clutch locking nut question.
« Reply #8 on: 27.07. 2022 02:26 »
Of course I did mean pressure plate and yes that is exactly what I meant by using a hammer. I wondered if my post was a little ambiguous after I posted it. It is amazing how flexible the clutch basket is even when it is one of the reinforced ones like mine.
NZ

Offline Swarfcut

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Re: 6 spring clutch locking nut question.
« Reply #9 on: 27.07. 2022 07:36 »
  Baskets and centres....I was talking chain wheels  when I mentioned baskets. This is the component subject to the greatest amount of wear, and is expensive to replace new. And yes, I've had them where the plates fouled on the fingers and the outer band.
   I can see Slymo is referring to the pressed steel centre, the one that carries the plain plates. This part has its own design fault, notably the poor concept of riveting the spring pillars to the base. They inevitably become loose, rotating with the adjuster nut, then needing surgery to dismantle the clutch. The usual repair is a crude dab of weld or braze. I've used another good centre with the pillars held thread to thread with adjuster nuts, to act as a jig, keeps them all standing to attention while I wield the torch.

 Swarfy

Offline Hughsie

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Re: 6 spring clutch locking nut question.
« Reply #10 on: 28.07. 2022 11:53 »
The factory instructions are for setting the clutch so you could pull a double adult side car with 4 kids & camping gear in it and deavily pregnant mum on the back without slipping .
IT is way too tight
put the front wheel against a wall so the bike can not move
Put the bike in top & attempt to kick it
Back the adjuster off 1 falt a time till the kickstarter just slips then tighten all of them 1/2 turn
You will find the clutch sooooo much lighter to use
A lighter clutch is easier on your wrist but more importntly easier on the pivot & lever so they don't flog out any where near as quickly .

Thanks for sharing this kickstarter technique, this will help a lot.
I dont seem to have much option to back it off any more as I'm at the end of the threads for the lock nuts. My only other option would be nylock nuts instead.
So i will work away at these other areas first then test with the kickstarter test.
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Offline Hughsie

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Re: 6 spring clutch locking nut question.
« Reply #11 on: 28.07. 2022 12:00 »
  Baskets and centres....I was talking chain wheels  when I mentioned baskets. This is the component subject to the greatest amount of wear, and is expensive to replace new. And yes, I've had them where the plates fouled on the fingers and the outer band.
   I can see Slymo is referring to the pressed steel centre, the one that carries the plain plates. This part has its own design fault, notably the poor concept of riveting the spring pillars to the base. They inevitably become loose, rotating with the adjuster nut, then needing surgery to dismantle the clutch. The usual repair is a crude dab of weld or braze. I've used another good centre with the pillars held thread to thread with adjuster nuts, to act as a jig, keeps them all standing to attention while I wield the torch.

Ahh yes! I did notice a few of them started to turn a little along with the adjustor nut, however they eventually caught some drag and stopped, it was something I did wonder when they were not set tight... interesting.   
To be honest this will be a life long machine for me so if down the line I need to upgrade this clutch then I will.
It's not a matching machine anyway so I am not adverse to upgrades, I want to enjoy it for years to come.
It's just the costs that's slowing me down hahah, so if I can get it all operating best I can for now I will keep saving the coppers. (Digital coppers. Bitcoins, or whatever we save now)
I've repaired fingers on my SR500 in the past and this did help, so it's a great reminder, these look kinda OK from what I cam see but im going to take a closer look .
Many thanks.

 Swarfy
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