The BSA A7-A10 Forum

Technical => Clutch, Primary, Gearbox => Topic started by: zitman on 15.04. 2009 12:35

Title: Strange Clutch Problem
Post by: zitman on 15.04. 2009 12:35
Hi all,

I recently fitted a 4 spring clutch conversion from George Prew to my '59 A7.

While out on the bike on Saturday the clutch stopped working.    When I fitted the conversion I had a few problems getting the centre nut to stay tight so I thought it had come loose again but checking through the inspection cap on the primary case and the push rod cover on the gear box, all seemed OK.  I stripped the primary cover and there was no play in the clutch basket.  I kicked it over a few (20 - 30) times with the clutch lever in and it free'd off.  I took the clutch apart anyway and all seemed OK.

Because I had to keep taking the primary cover off the get the clutch centre nut to stay tight initially, I had been running the primary dry.  Thinking this may be contributing to the problem I filled it with the appropriate amount of oil when I put it back together and all was OK.  On Sunday I went out and the clutch locked again.  A few kicks (10- 15) with the clutch in and it free'd again and has been OK since.

Just curious as to what is happening.  Is it likely that the lack of oil contributed to the problem?  I have trouble selecting neutral on the gearbox so prior to both lock ups I had been stationary with the clutch pulled in and the bike in gear at junctions etc.  Is it likely the clutch over heated?

Title: Re: Strange Clutch Problem
Post by: A10Boy on 15.04. 2009 15:49
It sounds to me like it did overheat which could have caused adhesive to migrate to the surface of the friction material. All you need is one area of a friction plate to bond to its adjacent plain plate to cause those symptoms. I imagine that it will be ok now its oiled.
Title: Re: Strange Clutch Problem
Post by: zitman on 15.04. 2009 17:20
I kinda thought it might be due to overheating.  The second time it locked up was after I had put the oil in though (only about 15 miles after!) but it could have been hot as I was waiting for a couple of minutes with the clutch in about 5 minutes before.