Author Topic: 4 or 6 spring clutch  (Read 1386 times)

Offline JHG1958

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4 or 6 spring clutch
« on: 17.09. 2019 19:26 »
My somewhat mistaken purchase of a 1961 A10’s has a 6 spring clutch loosely fitted.  Obviously thrown in to make it a nearly complete bike.  I understand that the 4 spring clutch is better.  Can anybody tell me why it is better and is it worth me looking for a 4 spring clutch?
John

Offline ellis

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Re: 4 or 6 spring clutch
« Reply #1 on: 17.09. 2019 20:43 »
4 Spring clutch every time and most of your troubles will disappear.

ELLIS 

Offline muskrat

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Re: 4 or 6 spring clutch
« Reply #2 on: 17.09. 2019 21:24 »
G'day JHG.
" has a 6 spring clutch loosely fitted" Ha, that's how I remember them, wobble wobble.
A lot of members retain the original 6 spring and with judicious assembly report success. I hate them (the clutch).
The 4 spring being a much later design is far superior and will last decades longer.
 If money isn't a factor I'd go for a Pearson clutch or as in my Cafe a belt drive and Notrun Commode diaphragm clutch.
Cheers
'51 A7 plunger, '57 A7SS now A10CR,  '83 CB1100F, 88 FXST .
Australia
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Offline morris

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Re: 4 or 6 spring clutch
« Reply #3 on: 17.09. 2019 21:33 »
*welcome*
I have no experience with the 6-spring but there are some advocates of that type on this forum so it can’t be that bad. I understood that it needs a bit of fettling to get it working right but well set up it’s doing the job.
I run a 4 spring setup on the SA and happy with it but a big improvement on that type is the SRM pressure plate kit with needle bearing pusher.
Doing with the 6-spring or changing to a 4-spring depends on how much you want to spend I guess.
BTW, an A10 never is a mistake purchase...  *smile*
'58 BSA A 10 SA
'52 BSA A 10 Plunger
'55 MORRIS ISIS
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Online Greybeard

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Re: 4 or 6 spring clutch
« Reply #4 on: 17.09. 2019 23:10 »
The 6 spring clutch fitted to the Plunger model is very good. Apparently the 6 spring clutch on the SA models is not.

Online Bsareg

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Re: 4 or 6 spring clutch
« Reply #5 on: 17.09. 2019 23:11 »
I've never quite understood the need for a needle roller on the end of the push rod, a mushroom to even the lift maybe,  but why the need for a bearing ? Surely the pressure plate turns with the gearbox mainshaft
and the pushrod so they all rotate together ? Anyone have an explanation?
C11,B40,B44 Victor,A10,RGS,M21,Rocket3,REBSA

Online chaterlea25

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Re: 4 or 6 spring clutch
« Reply #6 on: 17.09. 2019 23:21 »
Hi Reg
The "pressure" is on the bearing /mushroom or push rod end when the clutch is being released or pulled in when there is relative motion between the driving and driven parts

John
1961 Super Rocket
1963 RGS (ongoing)

Online Seabee

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Re: 4 or 6 spring clutch
« Reply #7 on: 18.09. 2019 02:50 »
I have a 6 spring in my 57 Road Rocket. It is hard to pull in. I have a 4 spring in my 61 Super Rocket and it is buttery smooth and easy to pull in.
1961 Super Rocket
1957 Road Rocket
2009 Harley Electra Glide Classic
1993 Harley Springer Softtail
1970 Harley Sportster Chopper
1957 Harley Panhead Chopper
1982 Yamaha XT550
2001 KTM EXC 400
1970 Honda CT70
Southern Illinois, USA

Online Bsareg

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Re: 4 or 6 spring clutch
« Reply #8 on: 18.09. 2019 09:58 »
I may be thick but still can't se where the relative motion is. Surely pressure plate and clutch centre are all on the driven side and,  even when the clutch is slipped, still locked together. Also the push rod is allowed to turn with the mainshaft by the bearing ball on the operating arm. I must be missing something somewhere. 
C11,B40,B44 Victor,A10,RGS,M21,Rocket3,REBSA

Online ironhead

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Re: 4 or 6 spring clutch
« Reply #9 on: 18.09. 2019 10:20 »
No your not thick, the only relative motion will be a slight bit as pressure is first applied to the pushrod ( spinning shaft , stationary ball in the r/h adjuster) I have found ( after making a few) that the main advantage of the alloy plate is the fact it is a snug fit over the clutch centre thereby centralizing it, whereas the standard pressure plate
sits on the first plain plate in the middle & only has the spring studs to centralize it.

ps    if the alloy plate is not a snug fit over the centre it is no better than the original.
Hope this makes sense.

SA

Offline duTch

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Re: 4 or 6 spring clutch
« Reply #10 on: 18.09. 2019 10:26 »
 
Quote
..... Also the push rod is allowed to turn with the mainshaft by the bearing ball on the operating arm...........

 In addition to ironheads comment who jumped in while I was tapping;
 Exactly- that's a small area to carry such a load, especially if sitting/standing still in gear. The tophat/mushroom bearing alleviates the load and allows the clutch to spin without necessarily spinning the pushrod (fwiw, the ball in my activating arm has a flat worn on it so I match it up with the pushrod so there's more surface area to take the load- works for me *whistle*).
 Gutzzis also have a radial roller bearing behind the actuating arm (not a standard size though so have to go 'special' *rant*)
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
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Online ironhead

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Re: 4 or 6 spring clutch
« Reply #11 on: 18.09. 2019 10:33 »
  G'day Dutch .  That is the side a proper bearing would be an advantage. Not much room though *work*
SA

Online mikeb

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Re: 4 or 6 spring clutch
« Reply #12 on: 18.09. 2019 10:59 »
like greybeard says, my recall (from reading other threads, not real life is) is there were two types of 6 spring. The earlier plunger semi unit 6 spring was well regarded but the later pressed steel centre S/A version is not much liked.  So maybe check which type you have?

The 4 spring on my a10 is reliable whereas the later pressed tin 6 spring on my b33 is wobbly and unpleasant. I'd love a pearson / belt drive setup but pockets aren't that deep.
New Zealand
'61 Super Rocket  - '47 B33 -  '18 Triumph Street Triple RS

Online Bsareg

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Re: 4 or 6 spring clutch
« Reply #13 on: 18.09. 2019 11:43 »
Thanks for the explanation chaps. It would seem that a flat mushroom would do the same job except for the  slight movement on the spring studs.
C11,B40,B44 Victor,A10,RGS,M21,Rocket3,REBSA

Offline JHG1958

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Re: 4 or 6 spring clutch
« Reply #14 on: 18.09. 2019 18:04 »
Thanks for all this. And whoever moved the thread to the right section. 

Money is not a big problem but at £400 the Pearson clutch will make me think twice.  Still it sounds a good investment.

My last A10’s thirty years ago had a triumph clutch with a conversion spindle. I have not heard this anywhere else so I am wondering if anyone else has heard of this or if I was mistaken. Good light clutch.

Maybe keep an eye for my 6 spring clutch for sale.  First I will get the rest of the bike together and see how the piggy bank looks.

John