This is taking shape in my friends workshop at the moment...A special constructed from the components of various BSA machines and a good scattering of one off parts...

It's a tuned, oversize B33 engine and the bike itself is modelled (quite) loosely along the lines of the pre war Wal Handley M23....Currently the BSA 8" front brake is undergoing conversion to Twin Leading Shoe....

Once overall assembly is completed it will be stripped for finish painting etc....Ian

email (option): ian@wright52.plus.com

Wow! You work in a bank vault!

:laughing: :laughing: ...It's an industrial workshop...Ian

email (option): ian@wright52.plus.com

Looks neat C11 /C12 4spd gearbox ? might want to modify that ex pipe or avoid r/h bends:laughing: . I am suprised at how many specials are M20 based I will be fitting a tuned B31 engine to my 48 rigid /girder M21 once I have V5C from DVLA and used it a bit..

The exhaust was a 'work in progress' when the photo was taken, so not in it's final format...You can see the unwelded cuts if you look closely...It is indeed a C11G gearbox, which is actually a plunger A10 gearbox with different main case mountings and a C11G specific main shaft...

However, both the plunger splined main shaft (which will take a Norton clutch) and the s.arm BSA main shaft (which will take a Triumph clutch amongst others) are a straight fit. This particular bike has a Newby belt kit fitted on a BSA s.arm shaft...

Being a 'camplate' gearbox with few differences to the s.arm gearbox, the gear change operation of the plunger type box matches the s.arm version and is a vast improvement over the M/B Series heavyweight 'mangle' gearboxes. It also weighs substantially less....Ian

email (option): ian@wright52.plus.com

%%bbCodeItem_1%%