The BSA A7-A10 Forum

Technical => Clutch, Primary, Gearbox => Topic started by: huddie on 31.10. 2012 15:54

Title: Play in clutch inner drum
Post by: huddie on 31.10. 2012 15:54
 Hello All, Looking at overhauling my clutch as bike is in bits. Clutch parts seem to be relatively expensive, up to the £300 mark for a complete replacement.
Although my clutch was working ok except for a bit of a clunk selecting first, my main concern is what seems to me to be excessive wear between the clutch inner drum and the clutch centre. I am assuming there should be none. is that correct?
If I am right which bit is the more likely to wear (ie try replacing that first), or should they be replaced as a pair.
Regards Huddie
Title: Re: Play in clutch inner drum
Post by: stu.andrews on 01.11. 2012 10:28

I know that play was acceptable on Triumph clutches but not sure about BSA. Someone will soon come up & tell us. Have you got a Triumph clutch fitted?
Title: Re: Play in clutch inner drum
Post by: Goldy on 01.11. 2012 10:41
The usual problem is the clutch bearing, the small double row ball bearing. It's a straight replacement although if you search the forum you will find that some people are using a one piece cage bearing as a replacement.
Title: Re: Play in clutch inner drum
Post by: huddie on 01.11. 2012 12:23
Hi Stu/Goldy, Dont know which one I have Stu, how do you tell the difference?. You've got me there goldy, not sure what you mean, the only bearing in my clutch is made up of all individual rollers, no complete bearing as such! If neccessary I will take pics of the two bits I am refering to to show you.
Regards Huddie
Title: Re: Play in clutch inner drum
Post by: Goldy on 01.11. 2012 15:49
The standard BSA clutch is the 6 spring whereas the Triumph clutch has 4 springs. if your bearing has rollers not balls it sounds as thou it has already been replaced with a new type. BSA service sheet No 308 shows a section through the clutch.     http://www.britishonly.com/pdf/bsa/sectionB_BSAservicesheetno308.pdf
Title: Re: Play in clutch inner drum
Post by: chaterlea25 on 01.11. 2012 20:11
Hi Huddie,
Ok so we are talking about the 4 spring clutch
There have been a lot of crap parts being peddled over the years
some clutch bits came from the far East and are not great to say the least  *sad2*
Some of the pattern parts supplied by UK suppliers are not too hot either????

The original shaft adaptors are made of a hardened material and should not wear easily (pattern ones are softer)
The clutch inner drums are something like a mallable casting and so are not as hard so I would suspect wear in this first
You dont state whether its a solid or cush drive type ?
An important check to make is that the inner drum is clamped solidly when the centre nut is tightened
The shaft adaptor outer face should not be proud of the face on the clutch body
This means the nut / washer (thick) should clamp the body against the inner lip where the rollers run
Make sure you have the correct length rollers (0.225in??)

HTH
John