BSA ZB32 Gearbox

[john64]

Hello
could anyone point me in the direction of a uk supplier of new or used gearbox parts.
The parts I require are kickstart pawl and kickstart ratchet. Looking at pics and parts books on line I cannot see any to match mine. Both are geared with 17 teeth rather than the plain ungeared ratchet listed everywhere.
I have attached a few pics to show what I mean.

[JulianS]

Does you gearbox look like this one?

What year is your bike?

[john64]

Yes this is the gearbox I have. Do you have part numbers list as well.
Thanks
John

[john64]

My bike was registered in 1984 but was manufactured in 1948 it is a ZB32 Competition rigid.

[Pete C]

I recently rebuilt one of these boxes, a right pain! the kickstart being inside the main box rather than in the outer cover as in the prewar and post '48 Versions makes lfe interesting.

Draganfly have a list of the part numbers on their site at

https://www.draganfly.co.uk/index.php/bsa/bsa/a710--b3133--c101112--m202133/category/902-b-m-group-1938-62-plunger-rigid

they are not in the Illustration but you can work out most from the table below it. Then go hunting on ebay...I had to get parts from Australia!

Cheers
Pete

[JulianS]

The parts books up to 1952 had a different format to the later ones and they covered the whole model range.

The first ZB32 engined bikes left the factory in November/December 1948 for the 1949 season.

The box in question was, as far as I know, only used 1946-48 when it was replaced by the M type.

If you visit the BSA A7 A10 forum you will be able to download the complete 1948 parts book which you may find useful. Or contact me by PM.

In the meantime here are some of the gearbox pages from the 1948 book.

[john64]

If I can't source these gears is there another gearbox that would fit ?

[JulianS]

I thought the ZB bikes had the M type box fitted.

You might get one in your bike.

[Pete C]

The M and later B boxes would not fit between the mounting plates unless you machine the gearbox case.

Here is a reply to my problems with this box, made by Ian Wright on the WM20 Website Forum.

"These boxes are a further development of the gearbox fitted to the WB30...Another problem apart from the scarcity of parts is the fact the box has a fairly short main shaft and as they were only fitted for two years the correct clutch sleeve isn't that easy to find either...Further, only the poor quality (IMO) 6 spring clutch will fit...

Additionally, being of a far lighter construction than the box that ultimately replaced them I have found they haven't stood the test of time as well either...Unless you are determined to use the type I would consider machining the mounting lugs on the later box to suit the early gearbox plates and fitting one of those, thus solving all the problems in one go!..Replacing the kickstart return spring is a lot less hassle on the later box as well..."


I have a spare later box that I will be modifying to fit as I still am not happy with how the 46-48 box is behaving on my bike.

good Luck!

Pete