Author Topic: Bsa A10 plunger clutch plates  (Read 809 times)

Offline anjimehra

  • Valued Contributor
  • ****
  • Join Date: Feb 2009
  • Posts: 343
  • Karma: 0
    • venture on wheels
Bsa A10 plunger clutch plates
« on: 29.07. 2017 07:52 »
Hi guys
Preparing my 1952 plunger flash for a long haul & cannot find cork lined clutch plates to carry as spares. Had converted the clutch to wet type. Clutch will take a hammering as we are firing up to 18500 ft on not so good roads . So my question is
1) Only rubberised cork plates available here. Will these last in oil
2) What is the dia of the plate as I can't remember & don't want to strip the clutch side.
Thanks
Anji

adm: title edited to reflect content

Offline Sluggo

  • Serial Hoarder, or Eccentric Collector depending on viewpoint
  • Resident Legend
  • *****
  • Join Date: Jun 2017
  • Posts: 639
  • Karma: 11
Re: Bsa A10 plunger clutch plates
« Reply #1 on: 29.07. 2017 08:44 »
Important spares on a road trip is ALWAYS a good idea. At a minimum is spare throttle, and clutch cables and small tool kit.
But to directly answer your question, I dont know personally of anyone offering replacement cork clutch parts.  I think I have a few cork segments in packaging from long ago parts inventory purchases but I did not take them seriously and not even sure where they are at in storage.
I have been sorting parts lately and know I have a bunch of clutch plates that are that early style and some still have the segments in them and some are just the bare steel plates with holes for the corks.
I cannot tell you about "Rubberized" plates as I have never seen such a thing personally but to my knowledge most people just use a more modern type clutch plate with regular friction material such as what a Unit BSA A65 would use.  To my limited knowledge on early A10s I though such plates were sold with regular friction material?  I dont know of any suppliers who sell the cork little pieces.
Now, I have not visited India yet,, (Very likely in November this year) BUT in many countries I have visited there are thriving rebuilding specialists who will re-line old clutch plates, brake shoes and recapping tires.  Is it possible to have some spare plates relined with modern materials?
I have a friend who has experimented with relining old vintage American bikes (Indians & Harleys) with the brake shoes with a modern Kevlar friction material.  Most US shops wont touch vintage motorcycle brake parts but Mike bought several grades of the brake pad material and researched the glues and techniques to apply the materials.  He found a few types that really worked and my friend with his 1940s Indian Scout says he can skid both front and rear tires now and that was never possible before.
So, point is, can you resurface clutch plates thru a vendor?
I remember the problems we had once circa 1988 and a friend and I agreed to replace the clutch in a ladies car while living in Turkey. We had the pressure plate rebuilt and the clutch plate relined.  It went together well but she complained it locked up and could not get it out of gear.
Took 4 attempts before we figured out the problem.
The friendly vendor (Good deal for you my friend!) had added too thick material and as it heated up the whole thing locked up. We had to take OFF some material (Thinner) and it worked great after that.
So, we were not so smart as we thought! 
Remember that any advice received on a free internet forum is generally worth about 1/2 of what you paid for it.
We overcharge every 3rd customer to pass the savings onto you.
You can have High Quality, Low price, and fast turnaround. Pick any 2, Never all 3 at the same time.

Offline anjimehra

  • Valued Contributor
  • ****
  • Join Date: Feb 2009
  • Posts: 343
  • Karma: 0
    • venture on wheels
Re: Bsa A10 plunger clutch plates
« Reply #2 on: 29.07. 2017 09:14 »
Hi Sluggo
Thanks for feedback. Nobody currently doing cork insert fitting here. Replacement plates are either rubberised cork ( supposed to run dry & exported to UK.) or a sort of Ferraro lining (similiar to car clutches ) Have located some OEM inserts but need to find friction plates with cutouts. Problem is time. Any idea what the plate dia should be. Two options are 5.5 or 6 ins.
Let's meet up in Nov if you Mumbai or Pune side




Offline Sluggo

  • Serial Hoarder, or Eccentric Collector depending on viewpoint
  • Resident Legend
  • *****
  • Join Date: Jun 2017
  • Posts: 639
  • Karma: 11
Re: Bsa A10 plunger clutch plates
« Reply #3 on: 29.07. 2017 09:36 »
I am off to bed and wont have time until tomorrow evening to look at parts. I am happy to get you measurements for what I have here and take pictures.  I would be happy to send you some plates with the cutouts but I believe it would take too long to get to you.  I can check my clutch parts and see if a A65 or similar later plate will fit. I simply am not sure as I am still learning this A10 stuff and my knowledge is mostly later BSA.  (A65).  While I have owned some of these A10 projects for years, I am just now getting to the point of working on them. Hence my joining this list.
I am sure more knowledgeable members will know, but if the need is there by tomorrow I am happy to assist what ever I can!
Cheers!
Remember that any advice received on a free internet forum is generally worth about 1/2 of what you paid for it.
We overcharge every 3rd customer to pass the savings onto you.
You can have High Quality, Low price, and fast turnaround. Pick any 2, Never all 3 at the same time.

Online WozzA

  • Wise & Enlightened
  • *
  • Join Date: Nov 2011
  • Posts: 1321
  • Karma: 17
  • Melbourne Australia
Re: Bsa A10 plunger clutch plates
« Reply #4 on: 29.07. 2017 09:50 »
Anli... I purchased a set a couple of years ago from Modak in Melbourne,
http://modakmotorcycles.com.au/
'51 Golden Flash Plunger
'57 Golden Flash Swingarm

Melbourne
The biggest lie I tell myself is
"I don't need to write that down, I'll remember it"

Offline duTch

  • Ricketty Rocketty Golden Flashback
  • Wise & Enlightened
  • *
  • Join Date: Oct 2011
  • Posts: 4540
  • Karma: 41
Re: Bsa A10 plunger clutch plates
« Reply #5 on: 29.07. 2017 10:03 »
 OD= 5,5/8" (143mm).

 Overall to outside of tabs =5,13/16" (148mm)

 ID = 3,35/64 (92mm)

 A not-so-good pic attached; is the fifth of the set of five, that I replaced but I decided five is too fat so took one out.

 Maybe I have a spring issue...

 Further edit; this is a new Plunger model Clutch plate from Draganfly, I think the Swing arm ones are bigger Dia.
Started building in about 1977/8 a on average '52 A10 -built from bits 'n pieces never resto intended -maybe 'personalised'
Have a '74 850T Moto Guzzi since '92-best thing I ever bought doesn't need a kickstart 'cos it bump starts sooooooooo(mostly) easy
Australia

Offline Sluggo

  • Serial Hoarder, or Eccentric Collector depending on viewpoint
  • Resident Legend
  • *****
  • Join Date: Jun 2017
  • Posts: 639
  • Karma: 11
Re: Bsa A10 plunger clutch plates
« Reply #6 on: 01.08. 2017 04:05 »
Anji, et al, I spent some time on this issue and tried to figure this out.  I am in the midst of sorting many parts that have not seen the light of day for well over a decade.  I know I still have one more box of clutch bits and plates somewhere I have not located but I spent some time looking at various BSA parts books for twins and singles, swing arm, plunger and rigid.  A-B-C & m series.
My experience is mostly on later Unit twins and more towards Norton & Triumph so, I am a little lost here.
I also read a number of postings here and on BritBike to gain some insights and confused as ever.

But...My project 52-3 A10 Golden Flash (Could be a HOTFLASH if someone was motivated) is missing its clutch so I am not able to measure a known entity. It ALSO appears there is some variations in some of these parts and dimensions based on numerous threads I looked at.  Finally, its possible people have swapped around different parts so my point here is:

a 51-52 bike could be anyones guess what is fitted.

So, do you have the factory parts book? I can send you  a copy digitally or a link to download one.  But based on what the factory said they used, I have ONE basket I found so far that matches the factory description.  I have a number of other baskets that clearly are BSA variants and years but I started sorting and cataloging what I have so I needed to do this anyway.  (I am knee deep in the Norton and Preunit Triumph dept right now)

What I have found so far is I have a LOT of segmented clutch plates with the replaceable friction bits. You are correct that many are of a cork material. Did not notice anything rubbery but what the hell do I know???  Plus there is more storage areas and inventory to go thru.

I will be doing at some point a Clutch bits ID thread separately,, But hopefully these pictures are helpful in some fashion for you or anyone else sorting this issue out.

The friction and plain steel plates have an OD of Approx 140mm not counting the tabs.  For reference, later type Unit single plates while small dont appear to interchange.  The later Unit type BSA & Triumph plates are way too large..  But there is a number of different sized plates out there, as well as the tab spacing and sizing differs.

Interestingly I have some plates the same OD (140mm) but instead of male (Proud) tabs they have female notches.  I dont know if this is a modified setup or there is some obscure application for these.

As a tangent, I have saved clutch baskets over the years and in a few cases when the notches for the male tabs get too far worn (notched and sloppy) we notched the clutch plates instead and tack welded in hardened steel pins into the basket. This worked well and extended the life of the baskets which are quite expensive to replace.  It might be possible to find some asian bike application and ADAPT plates from that as a common sense adaption.  Or.. ,more sensibly adapt a modern clutch unit similar to the Pearson-Suzuki mod.

Let me know if I can assist further....
Remember that any advice received on a free internet forum is generally worth about 1/2 of what you paid for it.
We overcharge every 3rd customer to pass the savings onto you.
You can have High Quality, Low price, and fast turnaround. Pick any 2, Never all 3 at the same time.

Offline Sluggo

  • Serial Hoarder, or Eccentric Collector depending on viewpoint
  • Resident Legend
  • *****
  • Join Date: Jun 2017
  • Posts: 639
  • Karma: 11
Re: Bsa A10 plunger clutch plates
« Reply #7 on: 01.08. 2017 04:07 »
heres some more
Remember that any advice received on a free internet forum is generally worth about 1/2 of what you paid for it.
We overcharge every 3rd customer to pass the savings onto you.
You can have High Quality, Low price, and fast turnaround. Pick any 2, Never all 3 at the same time.

Offline anjimehra

  • Valued Contributor
  • ****
  • Join Date: Feb 2009
  • Posts: 343
  • Karma: 0
    • venture on wheels
Re: Bsa A10 plunger clutch plates
« Reply #8 on: 26.10. 2017 08:20 »
Anji, et al, I spent some time on this issue and tried to figure this out.  I am in the midst of sorting many parts that have not seen the light of day for well over a decade.  I know I still have one more box of clutch bits and plates somewhere I have not located but I spent some time looking at various BSA parts books for twins and singles, swing arm, plunger and rigid.  A-B-C & m series.
My experience is mostly on later Unit twins and more towards Norton & Triumph so, I am a little lost here.
I also read a number of postings here and on BritBike to gain some insights and confused as ever.
Thanks Sluggo
Sorry for not replying earlier but have just returned from the road trip up in the Himalayas. Was away for 10 weeks & only just got back & saw your posts. Really appreciate the effort taken by you to help. Finally decided to leave the Flash & take my 500 Enfield. Just as well because the terrain mostly was very tough with bikes climbing in 1st & second gear all day. Getting back into restoration mode & will revert asap.
When do you arrive in India. Any chances of meeting up. Would be fantastic if we could
Take care, Anji

But...My project 52-3 A10 Golden Flash (Could be a HOTFLASH if someone was motivated) is missing its clutch so I am not able to measure a known entity. It ALSO appears there is some variations in some of these parts and dimensions based on numerous threads I looked at.  Finally, its possible people have swapped around different parts so my point here is:

a 51-52 bike could be anyones guess what is fitted.

So, do you have the factory parts book? I can send you  a copy digitally or a link to download one.  But based on what the factory said they used, I have ONE basket I found so far that matches the factory description.  I have a number of other baskets that clearly are BSA variants and years but I started sorting and cataloging what I have so I needed to do this anyway.  (I am knee deep in the Norton and Preunit Triumph dept right now)

What I have found so far is I have a LOT of segmented clutch plates with the replaceable friction bits. You are correct that many are of a cork material. Did not notice anything rubbery but what the hell do I know???  Plus there is more storage areas and inventory to go thru.

I will be doing at some point a Clutch bits ID thread separately,, But hopefully these pictures are helpful in some fashion for you or anyone else sorting this issue out.

The friction and plain steel plates have an OD of Approx 140mm not counting the tabs.  For reference, later type Unit single plates while small dont appear to interchange.  The later Unit type BSA & Triumph plates are way too large..  But there is a number of different sized plates out there, as well as the tab spacing and sizing differs.

Interestingly I have some plates the same OD (140mm) but instead of male (Proud) tabs they have female notches.  I dont know if this is a modified setup or there is some obscure application for these.

As a tangent, I have saved clutch baskets over the years and in a few cases when the notches for the male tabs get too far worn (notched and sloppy) we notched the clutch plates instead and tack welded in hardened steel pins into the basket. This worked well and extended the life of the baskets which are quite expensive to replace.  It might be possible to find some asian bike application and ADAPT plates from that as a common sense adaption.  Or.. ,more sensibly adapt a modern clutch unit similar to the Pearson-Suzuki mod.

Let me know if I can assist further....