The BSA A7-A10 Forum

Technical (Descriptive Topic Titles - Stay on Topic) => Gearbox, Clutch, Primary => Topic started by: anjimehra on 02.12. 2015 10:38

Title: 1952 plunger flash clutch
Post by: anjimehra on 02.12. 2015 10:38
Hi guys
Greetings from sunny Pune, India
A query regarding clutch. I know the swinging arm clutch sprocket has a friction lining. Should the plunger also have facing on the sprocket?
Am thinking of converting the dry clutch to a wet one using cork facing & removing the clutch housing that keeps the plates dry. Any suggestions please
Anji
Title: Re: 1952 plunger flash clutch
Post by: duTch on 02.12. 2015 11:09

 Hi Anji, no it doesn't have the rear friction plate, but it does have one plain plate that is thicker than the others, and that goes at the back of the stack (important).
 The parts book says five friction plates and five plain plus the one thick plain one, but I found four works fine and five of each is too many, as I couldn't get enough spring preload.

 I've never used the cover partly because I initially was experimenting with plate numbers, and wasn't going to be stuffed doing the 12 nuts as well as the rest of the procedure, and it works fine without it.

 There was some discussion about the pros and cons of that not so long ago.
Title: Re: 1952 plunger flash clutch
Post by: muskrat on 02.12. 2015 18:49
G'day Anji.
As duTch said the clutch can be run wet (cover removed) but I prefer to leave it as is. The cover stops the basket from spreading.
Anyone that has a plunger knows it was the best BSA clutch.
Cheers
Title: Re: 1952 plunger flash clutch
Post by: anjimehra on 03.12. 2015 07:56

 Hi Anji, no it doesn't have the rear friction plate, but it does have one plain plate that is thicker than the others, and that goes at the back of the stack (important).
 The parts book says five friction plates and five plain plus the one thick plain one, but I found four works fine and five of each is too many, as I couldn't get enough spring preload.

 I've never used the cover partly because I initially was experimenting with plate numbers, and wasn't going to be stuffed doing the 12 nuts as well as the rest of the procedure, and it works fine without it.

 There was some discussion about the pros and cons of that not so long ago.

Thanks duTch
Another Query. Will the BB31or A 7  Plunger clutch sprocket fit on the A 10 ? A10 parts very difficult to get here.
Title: Re: 1952 plunger flash clutch
Post by: anjimehra on 03.12. 2015 08:00
G'day Anji.
As duTch said the clutch can be run wet (cover removed) but I prefer to leave it as is. The cover stops the basket from spreading.
Anyone that has a plunger knows it was the best BSA clutch.
Cheers
Hi Muskrat
Thanks. The clutch on my A 10 didnt come with the cover on it & was running cork plates in oil. Probably leave it as such. Dont want to get into the hassle of finding / making a cover.
Cheers
PS where are you located currently?
Title: Re: 1952 plunger flash clutch
Post by: muskrat on 03.12. 2015 18:22
G'day Anji.
I'm south coast New South Wales, Australia.
duTch is up Brisbane way.
cheers
Title: Re: 1952 plunger flash clutch
Post by: Greybeard on 03.12. 2015 19:58
Anyone that has a plunger knows it was the best BSA clutch.

I'm happy with mine
Title: Re: 1952 plunger flash clutch
Post by: morris on 03.12. 2015 21:16
Anyone that has a plunger knows it was the best BSA clutch.

I'm happy with mine

Count me in... but can't say anything negative about the 4 spring set up in the SA neither.
Title: Re: 1952 plunger flash clutch
Post by: anjimehra on 04.12. 2015 11:41
Cant find a clutch sprocket for the flash, but still looking. Is it true that the clutch sprocket off a unit Triumph 500 / 650 will match up with the clutch centre of the Flash ? but would mean using the friction plates off the triumph as the slots are different . Maybe I can get hold of this sprocket
Cheers
Anji
Title: Re: 1952 plunger flash clutch
Post by: muskrat on 04.12. 2015 18:52
http://www.vintage-motorcycle.com/index.php?language=en&site=4&pid=12&id=19486&limit=0
Sorry don't know about the triumph match.
Cheers
Title: Re: 1952 plunger flash clutch
Post by: chaterlea25 on 06.12. 2015 22:14
Hi anjimehra

Heres a link to a plunger model clutch

http://www.ebay.co.uk/itm/BSA-A10-A7-6-SPRING-CLUTCH-GOLD-FLASH-PROJECT-/252197706733?hash=item3ab8279bed:g:GPAAAOSwHQ9WYBaW

HTH
John
Title: Re: 1952 plunger flash clutch
Post by: muskrat on 07.12. 2015 07:46
G'day John.
Would the basket be from another model? It doesn't have the flange and studs for the cover.
Cheers
Title: Re: 1952 plunger flash clutch
Post by: chaterlea25 on 07.12. 2015 18:26
Hi Muskie,
I really dont know ? it looks as though tha basket and chainwheel have been separated?
Are these rivited together ?? does the flange fit between the parts?
I dont have much experience of the plungers

John
Title: Re: 1952 plunger flash clutch
Post by: duTch on 07.12. 2015 20:29

 
Quote
....... It doesn't have the flange and studs for the cover.
Cheers
Quote
...... ?? does the flange fit between the parts?

Maybe it's been machined off, should be integral with the chainwheel
Title: Re: 1952 plunger flash clutch
Post by: anjimehra on 11.12. 2015 14:34
Hi anjimehra

Heres a link to a plunger model clutch

http://www.ebay.co.uk/itm/BSA-A10-A7-6-SPRING-CLUTCH-GOLD-FLASH-PROJECT-/252197706733?hash=item3ab8279bed:g:GPAAAOSwHQ9WYBaW

HTH
John

Thanks John
Title: Re: 1952 plunger flash clutch
Post by: v8ivor on 27.12. 2015 19:31
I also have to many plates. Did you find that 4 plain plates including the thick one at the back + 4 friction plates and the pressure plate that has a plain plate fixed to it, works OK ?
Thanks,
Ivor.