Author Topic: A10 clutch adjustment  (Read 5495 times)

Offline huddie

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A10 clutch adjustment
« on: 27.07. 2008 09:35 »
Hi all hope you can help? Having got my a10 running and hopefully ready for its MOT i tried it up the road a short way. All is well now except i am not happy with the clutch. Its a 4 spring version and when stopped on idle, in gear, a blip on the throttle causes the bike to creep. Could be the clutch is worn out could be adjustment (i hope). Have you guys any tips to make sure its adjusted correctly before i take the primary drive cover off again.

Regards Huddie

Offline fido

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Re: A10 clutch adjustment
« Reply #1 on: 27.07. 2008 12:31 »
If you have not had the clutch apart you should do so. You need to file any burrs off the edges of the plate tenons and file out any notches from the corresponding slots in the basket and clutch centre. You can check for warped plates by placing them on a sheet of glass to see if they rock about. Check that all the springs are the same length, if not you need a new set. If you have a dial gauge, use it to check that the pressure plate is releasing evenly, otherwise check this by eye. The Haynes book specifies 20W50 oil for the primary chaincase but many owners use automatic transmission fluid. I assume you do have a manual of some sort?

Online Brian

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Re: A10 clutch adjustment
« Reply #2 on: 27.07. 2008 15:19 »
Good advice. The only thing I would add Huddie is that it really is worth the time and effort, and cost if necessary, to get your clutch working properly. A good clutch makes a big difference to a bike.

Online RichardL

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Re: A10 clutch adjustment
« Reply #3 on: 27.07. 2008 15:57 »
It would also be a good idea to be sure you are getting enough push on the clutch rod that runs through the transmission.
There is an adjuster under the oval cover plate that may need attention.

Good luck and we look forward to some pictures.
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020 (if it's not cancelled and we are free to move about by then). Watch website at https://www.gentlemansride.com for details.

Offline huddie

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Re: A10 clutch adjustment
« Reply #4 on: 27.07. 2008 17:43 »
Thanks for the suggestions guy's. The clutch was in bits as was the rest of the bike when i got it. I cleaned everything up and put it together without checking anything!!. The old haynes manual i have is a bit vague, for example how much tension does one put on the spring caps. Also how do you adjust the pushrod by that i mean what measurements etc tells you that it is ok. It is rideable so i am going to press ahead with the MOT. and then have it all apart after.
Thanks Huddie

Offline fido

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Re: A10 clutch adjustment
« Reply #5 on: 27.07. 2008 20:20 »
When disengaged the clutch arm should be parallel to the gearbox. If I recall correctly, the angle of this can be coarsely adjusted by repositioning it on splines at the internal lever behind the oval cover. It is then finely adjusted with the grubscrew and you then adjust the cable for 1/16" play at the handlebar lever. If the pushrod is well worn you will not get full disengagement because the internal lever will be angled inward slightly.

Offline huddie

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Re: A10 clutch adjustment
« Reply #6 on: 28.07. 2008 08:22 »
Cheers Fido    i will take the oval cover off and check, and hopefully adjust. with regards to the push rod are there any tolerances/measurements to determine the extent of wear?
Regards Huddie

Offline dpaddock

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Re: A10 clutch adjustment
« Reply #7 on: 10.08. 2008 19:13 »
Whether the clutch arm starts parallel to the gearbox joint or ends there is not critical as long as you're within this range.
Spring force should be 5-6 ft lb of torque measured at the clutch arm pivot. Use a notched socket on your torque wrench; the notch is 7/16-inch wide in an an old/cheap 3/4-inch socket.
If you need to replace the push rod, you can use 1/4-inch hot rolled steel rod obtained from a local hardware store. Make certain you get a straight piece. The axial force on this rod will be approximately 90 lbf when fully extended.
The axial movement is approximately 1/8-inch.
What is essential is that the pressure plate disengages evenly. Clamp the handlebar lever and measure this disengagement with a feeler gage between it and the first plain plate in the stack as you rotate it. Any wobble will result in a dragging clutch, even with perfectly non-warped plates. Adjust the springs accordingly.
David
'57 Spitfire


Online BSA_54A10

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Re: A10 clutch adjustment
« Reply #8 on: 12.08. 2008 11:09 »
At this point in time I will jump in to add some confusion to the clarity.
The clutch springs need only to be tight enough so that the clutch dose not slip when YOU ride the bike in the manner that YOU ride it.
The specified clutch spring tension & factory adjustment proceedure is designed so that Billy Bunter, with his bigger heavier brother Bobby Bunter pillion, can ride up a 1:5 slope in top gear without the clutch slipping so that they can save money on fuel & buy more custard tarts.

In 1974 I met a lad who rode his A65 from the UK to Australia ( well most of the way anyway) . I was discusted to find that not only could I pull the clutch lever in with 2 fingers but no matter what I did I could not cause the clutch to slip.

He started his adjustment by putting the wheel against a brick wall with the bike in first gear.
He adjusted the springs down onto the pressure plate so that they just touched and squared them off.
From here he did them all up 1/2 turn and then kicked the bike over.
If the clutch slipped he did the springs up another 1/2 turn.
Once the no slip point had been arrived at he started the bike , reengaged 1st the fed out the clutch, if the bike stalled good, if not he did the nuts up 1/4 turn till it did. Then he readjusted the pressure plate for square lift if necessary.

The less spring tension the less the tendency for the pressure plate to bend and drag, also less wear on all the fulcrum points, cable & your wrist, fewer broken cables and cleaner gear changes.

Now the original pressure plate is a steel pressing so the strength & more importantly the stiffness is different in the rolling direction compared to across the rolling direction. The higher the pressure the more significant these differences become.
While you have the clutch apart & your credit card handy do yourself a big favor & buy one of the alloy pressure plate conversions even better get one with a top hat adjuster & a roller bearing on the lifter.

Bike Beesa
Trevor
Bike Beesa
Trevor

Offline huddie

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Re: A10 clutch adjustment
« Reply #9 on: 12.08. 2008 18:02 »
Thanks Trev but i need a bit more help. I guesss my prob is, I never had the benefit of taking it apart where by you get a good visulisation of how things ought to look. Bearing in mind mine is the 4 spring variant I am confused as to how far to tighten the springs in the first place.The bit from your response which I have enclosed in quotes is the bit i dont understand,      "He adjusted the springs down onto the pressure plate so that they just touched".     With the pressure plate in place the springs go half into the 4 cups, a bit of tension against the spring is then neccessary in order for th spring tensioner nut to make contact with the bolt inside the spring. As a base from which to start how far do i compress the springs, ie how much spring length should be visible as a start point. I tried with the spring tensioner nuts done up such that almost no spring was visible. Using the kick start with the bike in first gear the clutch and wheel will still spin with the clutch lever pulled right back to the handle bars. I have my fingers crossed for a response from you or anyone who can help.   Regards Huddie

Online RichardL

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Re: A10 clutch adjustment
« Reply #10 on: 26.08. 2008 23:31 »
I just assembled my six-spring clutch, yesterday, and affixed the primary cover. Having, a bit late, read David's advice about gauging the distance of the pressure plate to the first plain plate, I certainly will do that when it next comes apart for adjustment. (I'm glad I bought the 10-pack of gaskets.) The one thing I was experiencing when making the adjustment was uneven disengagement of the pressure plate. I took out all the disks and it appeared the plate was rubbing on the chainwheel. It turned out that it was rubbing on the tines of the basket. A little judicious bending of the tines fixed the problem, using eyes as gauges.

Richard 
Plan on signing up for the world-wide 2020 DISTINGUISHED GENTLEMAN'S RIDEon September 27, 2020 (if it's not cancelled and we are free to move about by then). Watch website at https://www.gentlemansride.com for details.

Offline fido

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Re: A10 clutch adjustment
« Reply #11 on: 27.08. 2008 07:43 »
As I understand it, with the 4 spring clutch you start by screwing the spring nuts in as far as you can with a normal flat screwdriver ie the studs are flush with the bottom of the screwdriver slots. You then incrementally adjust the nuts tighter until the clutch no longer slips, monitoring that the plate lifts off squarely as you proceed.

Offline huddie

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Re: A10 clutch adjustment
« Reply #12 on: 27.08. 2008 12:57 »
Cheers Fido, I haven't got mine screwed down quite that far at the moment. The clutch doesn't slip at the moment either but i guess it wont be long before it does as the clutch lever has to be let out quite a long way before it bites. However as it is at the moment the clutch is beautifully light, and my problem with creeping is gone as is the difficulty with finding neautral when stopped but with the engine running. Yet again this forum is a mine of information, thanks again guys. 10 packs of gaskets! where do you get those from and how much as i was considering making my own as the covers seem to be everlasting having to come off.
Regards Huddie

Offline dpaddock

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Re: A10 clutch adjustment
« Reply #13 on: 27.08. 2008 15:51 »
Did any of you read my posting, above?
Forget the gaskets and use a thin coating of Permatex Ultra.
David
'57 Spitfire


Offline fido

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Re: A10 clutch adjustment
« Reply #14 on: 27.08. 2008 16:35 »
We don't all have torque wrenches that go down that low. The 4 spring clutch is generally considered to be a better device than the 6 spring so it should not be difficult to get it working well.