Hi, does anyone knows what make these are? I think there a set but not sure. The mainshaft has left and right thread close together.



Thanks for looking, Michiel

email (option): m.wijbenga@hotmail.com

Hi Michiel..BSA C11G fourspeed box...very similar internally to the swinging arm and plunger A10 gearbox but with the selector mechanism of the plunger A10....Ian

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

Thanks Ian, not my first thought as these are very heavy for a 250. I had an earlier C11 with the heavy fourspeed gearbox for years: never any problems with the box.

I don't need them, so if someone has a useful purpose for it, contact me direct. They are both unused.

Regards, Michiel

email (option): m.wijbenga@hotmail.com

Hi Michiel, The C11 and C12 were unusual for a British 250 in that they didn't seem to be built down to a price (or light weight) quite as much as many others..the C12 is a particularly good bike but frequently ignored because of its small capacity...The gearboxes are a good source of spares for the plunger A10 or swinging arm boxes used on the larger models as the 250s didn't tend to do as many miles and didn't make as much power. Apart from the mainshaft many of the internal components are the same. Interestingly there are two sets of gear ratios for these boxes..one the same as the bigger models, one different. Unfortunately there is no way of telling externally what is in there!...Ian

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