A7/10 bitsa project

[trickytree]

Started collecting for this bike almost as soon as I had the A65 on the road. I already had an assortment of bits from that build lying around the place and as I wanted to keep cost as low as possible I never had any intention of it being anything other than a bitsa. The main aim of the bike is actually to be a bit of an advert for my work. I am a time served toolmaker by trade and have been slowly building up a workshop for a few years now. Originaly it was for a little extra income in my retirement but things are looking a bit grim in my line of work at the momment (we do maintanance work for local councils) so I may need to start looking fo work somewhat sooner than expected.

So, frame first, 1948 welded A7. As you can see it has been chopped.....badly. Fortunatly engine mountings are still there but little else. Rear end has been widened and I have started to put that back to standard spec. Shame the footrest mounts are gone but everything else I can live with.







Engine wise Im going to go a bit mad...cases are 52 A10 and I am going to fit a A50/65 head via some billet alloy barrels. A65 top end on A10 cases has been done before apparently, usual way is to chop the cases down and weld on a huge chunk of ally and then re machine to accept the standard unit top end. As I cant weld ally (and to be honest I dont want to get too involved in fabrication work prefering the machining side of things) I am making some new barrels instead.

Should end up like this...



I will quite probably change a few details along the way if I pick up something cheap (!!) but at the momment I have a Norton 82mm crank that is going to be rephased to 90 degrees. Clutch will be ....something...(I picked up a GS550 unit as thats what Phil Pearson uses but it wont fit in the plunger cases) and will be gear drive primary. Full flow oil filter on the presure side, alternator...was thinking of an electric foot where the dynamo usually lives , not sure yet.

Got a nice Norton 8" front wheel so will use that, will make a TLS brake plate for it and will also make a new ally rear brake drum to replace the knackered cast iron original I have in a crinkle hub rear wheel of unknown origin I have.

Ohh, and before anyone asks, I know full well its an awfull lot of pain for little gain, thats not why im doing it!!

[muskrat]

Sounds very Tricky, tree. I an often amazed at the things people come up with. Down here at the classic races you can see all sorts of incarnations. One of my favorites was a A10 Knucklehead. If it pleases you that's all that matters.
  I toyed with the idea of an A65 top end and re-phasing the crank to 76 deg. Still wonder if it would work.
   Good luck, hope your wearing a flack jacket.
Cheers

[trevinoz]

Tricky,
            Are you sure about gear driving the primary?
I am certain you will have a lot of fun riding in reverse. [Assuming that you will be using the BSA box and final drive.]
Then again you could fit an idler gear but I think space will beat you.
Interesting concept.
I look forward to seeing the final result.
Trev.

[chaterlea25]

Hi trickytree,
I have a couple of GS clutches and I have considered narrowing them a bit??? or a spacer between the cases??
Anyway I rekon you are kinda spoilt for choice with the plunger box and its splined shaft,
This will take a Norton clutch or a NEB speedway clutch straight on!!! what about using  a commando clutch?
Or belt drive unit???
Could you make me a set of A10 alloy barrels while you are at it?? *smile*LOL

Cheers
John O R

[trickytree]

Hi Trev, will be using an idler gear, looks like I will be able to mount an idler shaft where the tensioner usually lives.

John, its the diameter of the GS clutch that is the problem (although I think it would also be to deep). Ill pop that on one side for now (pencil it in for the A65) and look for a smaller clutch. Only possible problem I can see is if the bolt on gearbox system is not rigid enough...although there isnt going to be loads of power going through it so hopefully should be OK.

[bonny]

is it difficult to fit the gs550 clutch into a beeza ? i presume it can cope with lots more power than any old bsa/triumph twin can put out . is there much machining involved ?

[orabanda]

I gave a Suzuki GN250 clutch to a friend, who then fitted it to his Gold Star.
Works great, no slip, and significantly smaller than the GS550 clutch.

I think the bike was a 350, but can check if you are interested.

On this basis,It should work well in a plunger transmission.
Richard

[trickytree]

To be honest I jumped the gun somewhat and got hold of a GS550 clutch as apparently that is what Phil Pearson uses in his conversions. Its clear to me now I have it why Phil makes a complete new outer basket...the GS item has a built in cush drive that is part of the casting for the drive gear...I presume the goldies have a cush drive on the end of the crank like the twins so this is not needed. Must say it is a pretty large unit.

As I want to squeze an alternator onto the end of the crank I cant spare the room for a crank mounted cush drive so I need a smaller clutch with a cush drive. I went to Newark Autojumble yesterday and had a look around. Found a few the right size...one from a SP370 but it had a few bits missing. Heard someone say that Honda 250/360 G3 units have been fitted to Goldies and they fit straight on (must say I find that hard to believe but ya' never know) so i imagine that there are hundreds of options out there and its just a case of getting one the right size and making it fit.

Also I came up with the gear primary idea after I had got hold of the GS clutch so I now need to consider the crank mounted gear and an idler as I dont want to have to make any gears if I can help it.