C15/B40 rear brake drum

[Greenfield]

Does anybody know if the rear brake drums for the C15 and B40 are interchangeable? Part nos 40-6018 and 41-6010. They use the same shoes, bolts and locking plates, and chain, and without having them side by side on the bench it would appear that the only difference is 45 or 46 teeth on the sprocket.

[JulianS]

The chain line is different between the 2 drums?

[AWJDThumper]

Just comparing the two setups, as Julian says, the C15 chain is about 3 cm from the edge of the hub, whereas, the B40 is between 4-5 cm.

[JulianS]

The 46t drum for the C15 was listed as part 40 6014.

[Greenfield]

Thanks for that. It looks like the drums have the same diameter but must have different depths to keep the sprockets in line with the different size rear wheels fitted.

[AWJDThumper]

That's the case. When I restored my C15 I didn't realise that the replacement rear brake drum was off a B40 until I tried to re-fit the back wheel!

[SIE7RA]

I had difficulty replacing the rear wheel in my C15, I had to lever the forks apart, I had a look on the draganfly site and they list the same part number for the C15/B40 and with 45 teeth,the BSA C15 parts book list a 46 tooth as for a sidecar. Mine has 45 teeth how do I know if i have the correct one

[AWJDThumper]

The rear drums were:

C15:  40-6014 - 45T
         40-6018 - 46T

B40:  41-6010 - 46T

As said, the C15 drums are at least 1 cm narrower than the drum on the B40.

Dragonfly list them correctly except for the B40 sprocket which they list as 45T while everyone lists 41-6010 as 46T.