clutch hub

[DAVE BRADY]

Hi,

Filing will increase the clearance but the movement of the plates will be smoother. File just enough to make the edge smooth.  The same can be done to the hub for the plain plates.  This is something that can only really be done once but it depends on how many miles you are intending to do.  Any burrs on the tangs on the plates should also be lightly removed.  If you can get it working smoothly it could last a long time especially if the clutch is not abused.
These early clutch baskets and hubs are not easy to find and the plain plates are different to the other clutches used.  I would check all the plates for being completely flat as any distortion hampers getting the clutch working properly.

Dave.

[LightningAndStarfire]

The amount of wobble on my three spring clutch worries me. Any trick around to reduce it apart from new rollers?

[DAVE BRADY]

Hi,

New rollers will only help a bit and a clutch that has done a lot of work will have wear on the bearing surface on the centre and the ring on the basket.  If you replaced all of these you would see some improvement.  I think the design lends itself to being wobbly as it depends on the clutch plates and springs to keep the wobble to a minimum. 
If I had the technical ability I would, as a minimum, make a thrust washer to sit between the back of the cush drive and the basket.  This should help to keep things a bit more snug. 
I wonder if a modification to fit a Bantam type clutch radial roller thrust bearing would be possible?

Dave.

[Bess]

Hi,
    If refit costs start to increase maybe worth consider replacing with a BNR belt drive/clutch?

Best wishes...

[Mike Farmer]

 

Eventually after much etc. I couldn't get the wobble down to sensible so put BNR clutch in. Sounds quieter too.

Mike

[DAVE BRADY]

Hi,

I believe that the BNR primary set up does not have a cush drive so is it just the belt that softens the drive Does it work or is a slightly harsher transmission a trade off for a better clutch?

Dave. 

[Bess]

Hi Dave,
             The belt stretch is negligible so doesn't act like a cush drive (think of the belt as a timing belt which doesn't stretch). I find slipping the clutch a little more suffices not a lot to ask for a far superior clutch.

I am in the process of building a B31 plunger which came minus a clutch. It will have a BNR, as the cost is similar to the standard plus the sprocket, chain etc.

Best wishes...

[idie]

Just before the pandemic kicked off I did a lot of work on a friends A10. This was fitted with a belt drive the ride was quite harsh as no cush drive. The clutch was prone to dragging, so much so that he asked me to change back to a cush drive. I fitted a Triumph style four spring clutch. He loves it, he said it has transformed the bike. On stripping the belt drive clutch I found that the reason for the drag was that the bearing in the back of the drum was seizing. A strip down and filling with grease got it spinning again. No oil in chaincase with belt drive.

[DAVE BRADY]

Hi Bess,

The BNR clutch looks like a good option if renewing everything.  Does it need the tensioner like the Hayward set up?

Dave.

[Bess]

Hi Dave,
             On the A65, no the belt supplied is the correct length. The A10 and B31 the gearbox is adjusted in the normal way.

Best wishes...

[DAVE BRADY]

Hi,

Thanks for the reply.  Definitely worth considering.

Dave.