1950 a10 refurb

[Worty]

Its Me again ,

Sorry to have to dig this concern up again
Blasting of any kind of media is an invitation to disaster 
Unless,
every fitting, bush and blanking plug,  have been removed from the cases so that the nooks crannies and drillings blanked of by the factory can be visually inspected for remaining media and old crap and of course remove it
Same goes with oil tanks

John

Definitely.  When my engine was rebuilt after a meltdown, it turned out an oilway was blocked by something resembling a ball bearing.  As no-one could figure out what it was, we ended up assuming it was blasting media.  The guy who previously  built the motor (apparently, a professional🤣🤣🤣🤣🤣), failed to check the oilways.  Actually, it could have been something else as the inner crankcases had gouge marks in them from the crank forcing the object against them as it made its way round the engine.  Eventually, it was forced into the oilway (so we think) and stayed there until Bergs rescued it.

[trevinoz]

I would like to know also when the "carrots' were discontinued.
Possibly with the BA series?

[Flash Chris]

From carrots to clutches … the 2 diagrams of the A series clutch differ in that the second one has a double set of ball races, highlighted in red. Is one - the latter? - a swinging arm variation? Cheers

[BagONails]

I would like to know also when the "carrots' were discontinued.
Possibly with the BA series?

Trev, If you have a look at the 'Just Beezas' Facebook Group there is an article on these covers with carrots by Brian Pollitt.
I ran into Brian when he came over here for our international Rally in Adelaide a couple of years ago. My own A10 has one of these carotty side covers and he pointed them out to me, I hadn't even noticed them before that point  . He maintains they only appear on side covers made by PBM (Perry Barr Metals) one of three different suppliers of these die castings to BSA. He says they (the carrots) appeared when the Super Flash model started in 1953 and are present on all PBM castings for that year (with and without rev counter drive bosses).
They are quite rare as they disappeared when the Road Rocket model came out in 1954 so only produced for about one year.

All this proved to me that my bike A10 1959 Golden Flash was indeed a bitsa having not only the wrong alloy head but also an incorrect outer timing cover to boot albeit interesting parts in their own right. Now Chris is in the same boat, sorry mate!

I'm not sure if anyone knows why the carrots were ultimately removed, maybe PBM got in a bit of a stew with BSA for parts made not to  drawing

Just for the record the other two companies involved were APDP (Alloy Pressure Die Products) and AM (Aeroplane and Motor castings)
No carrots ever seen on their products to date. The separate companies generally all put their own Trade Marks on the inside of these covers and there are other variances too.

 

[Flash Chris]

Interesting information Mr Nails. But if they only appeared for one year from ‘53 -  ‘54 then doesn’t that imply that pre ‘53 models shouldn’t have carrots? And therefore my casing is correct? 

[Worty]

I'm not sure if anyone knows why the carrots were ultimately removed, maybe PBM got in a bit of a stew with BSA for parts made not to  drawing

Maybe the carrots got put in the stew?

[Swarfcut]

  "6 Spring Clutch" can mean the FAR SUPERIOR Plunger Clutch...... Duplex chain, solid centre, splined directly to the gearbox main shaft........ Or the mediocre excuse with the pressed steel centre, single row chain and variable quality adaptor for a tapered gearbox main shaft. Plenty on the Forum about both.

 They are completely different and do not interchange. The excuse type is the S/A version, superseded (when someone saw sense) by the 4 Spring clutch which is actually a Triumph design.
 
  Swarfy.

[Flash Chris]

So the second clutch with the caged roller bearings is from the swing arm version?

I do know about the Triumph clutch version/conversion, just checking that my plunger doesn’t need the bearings in the second picture as both pics depict 6 spring clutches.

Thanks.

Edit - I also notice now the difference in primary chains, thanks for pointing that out!

[Swarfcut]

  The plunger clutch uses uncaged 1/4" X 1/4" rollers. You need a keen eye to spot a single example in the above diagram...there are actually 18. Some examples offered are actually metric and marginally too long..... just enough to lock up between the clutch centre and Ithe supporting thrust washer. So care needed to get what you actually want.

 For those folks missing the balls from the races of the infamous 6 Spring.... They are 3 /16",  widely used by the bicyclists so available easily from any number of online cycle parts sellers. Same goes for the skinflints among us just replacing head race balls.... Just order 1/4" from the same sources.

 Swarfy.

[trevinoz]

Nails, that information about the "carrots" is incorrect.
They were on the early covers without the internal shroud and I am sure that all 1950 -52  at least had them.
They are not rare at all, I have several.

[BagONails]

Looks like I've been sold some duff info there then thanks for the update Trev. Not sure I've got the energy to take Mr Pollitt to task over this however! Just goes to show you can't believe anything you read on the interwebs 

To be honest I'd be happy as long as it keeps the oil on the inside. So the shrouding around the breather was due to the addition of the rev counter drive as a later change was it?

[Rex]

  The plunger clutch uses uncaged 1/4" X 1/4" rollers. Some examples offered are actually metric and marginally too long.....
 Swarfy.

Indeed. This was an issue some years back with Triumphs, where someone suggested going to the nearest industrial bearing stockist and buying the rollers there rather than from a Triumph parts stockist, and then posting said suggestion on t'Interwebby.
From memory, there's only 2-3 thou in it but enough to cause problems.
Cue "why has my clutch locked up on assembly?" posts.

[JulianS]

The "Carrots". A bit more information.

My A10 had a "Carrots" outer timing cover plus the oil baffle or shroud.

Look at the ebay item

https://www.ebay.co.uk/itm/166378424469

Note the "carrots" and note the oil baffle and provision of r/c drive if the extra machining was done.

Roy Bacon in his book BSA Twin Restoration page 58 says the shroud was added  from 1952.

[Rex]

Just checked, and my '51 ST has carrots. Yay!

[Flash Chris]

That’s it. I’m buying some metal stamps and putting neeps on mine