FT: Frame (Twin) Early Twin Clutch

Len Matthews

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While I have seen this picture before I have not had access to it at this resolution.
By enlarging (with a single click) much more detail becomes visible. There are details I have never noticed before like the headlamp mounting, the simmonds nuts on the handle bar clamps and balance beam pivot, the top girdraulic padbolts having their nuts on the back (I'm sure I fit them on the front), silvery propstand plates and lower spring cases, regulator on pillion plate. Even the engine number is legible.
What a great picture. Does anyone have similar quality pictures of the other side?
There appears to be a key protruding from the speedometer or is that an ignition switch?If so, where's the speedometer?
 

BigEd

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I have seen somewhere, That the Mk1 Clutch ony used 3 springs !!, A mod' Dave Hills told me to do, Which works on one of my Twins, But not the other !. Cheers Bill.
Dear Bill,
I think I have read something similar. It also said that it was so light that if the cable wasn't very good the three springs couldn't overcome the friction in the cable when the clutch lever was released. I might try it sometime as it doesn't require a full strip to do.
 

Bill Thomas

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I tried it years ago and it was no good, But I forgot I tried it again, Till I stripped the Special and found only 3 springs !. I wondered why that clutch was so light.
As long as you have good contact between the steel plates and the primary plate, It will be fine,
Maybe fit nylon lined cable.
My steel plates are 1950, Not very good, I really should have bought new, But Too mean !.
Some days I have a lot of pain in my hands, So the lighter the better for me.
Cheers Bill.
 

Joe

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Hi, my B Model from 1948 has the very same clutch shoe pivot as on Simon`s picture.
How much play is acceptable for the clutch shoe pivot hole as I am experience clutch judder as described on page 69/70 in Paul Richard`s maintenance book. I can move the shoe sidewise about 1/8 inch.
 

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Simon Dinsdale

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One theory is you need a little play to help the shoes align with the drum but I would say the amount of play you have is excessive. My Rapide shoes had that amount and used to judder a lot and I had a friend rebush them with an oilite bush and that cured the problem. He also bushed the plunger bore which can be done but one shoe needed some welding to build up the area.
 

Bill Thomas

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I don't think that's your problem, But I did as Simon says and used the bushes out of the cam shaft,
It should be lined up to bore the holes, But I just did it free hand and took a chance. The springs and plungers
in the shoes are a lot of the trouble, The plungers must be free and the springs at the right tension.
With the shoes on the Bike but not the plates, By turning the shaft by hand, both ways, The shoes must not touch the drum, Should be about 20 to 25 thou gap between the shoe linings and the drum.
If you put the Bike in gear and move the shoes clock wise and anti clock by holding the nine pins,
You can see how the shoes move to contact the drum.
Good Luck, Bill.
 

Joe

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thanks everybody for advise.
As I am already checking thru the clutch, I started by adding chamfer on the edges of the shoe linings resulting in considerably reduction of clutch judder.
Next step will be bigger diameter C5 Shoe pivot nut to reduce excessive sidweise play of the shoes.
Once clutch is fine, will move on to check the ESA.
Cheers, Joe
 

Joe

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Hi,
the clutch of my B-Rapid operates now smoothly and I am happy after eleminating excessive play reworking bores and fitting newly made C4, C5/1 and C20 of under/oversize dimensions.
 

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Rob H

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In the process of disassembling an early Rap, same clutch as shown above with the nut shoe fixings and the washer underneath. The C4 bolts have been hammered into the slots of the nut so to get them off all I can think of is getting a cutting disc on a dremel and cut down thought the bolt until the slot is clear.

Is this method Ok or does anyone have another trick/tip to loosen these?
 

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