Bantam rear wheel

[Tomlinson]

I have. B26...1937.No back wheel.
I have seen I can fit a Bantam half width hub.
Anyone got a 18” for sale?

[spaceman]

I believe all the swinging arm Bantam's used a half-width rear hub and the switch from 19" to a 18" rear wheel was from model D5 onwards. I haven't looked in detail but I believe the rear hub design changed over the period from model D5 to D175.

Just curious whether you were simply after a rear hub for a particular later model or whether you were planning to use an 18" Bantam rear wheel as is? If the latter, I would have thought the wheel offset is unlikely to be the same for the B26 and the Bantams and, for old wheels, it can be difficult to adjust the offset because of corrosion on the nipples and spokes?

[Tomlinson]

I am trying to fit it to B26 rigidrear end.
Maybe I will be better off with the earlier ones without the speedo drive?
Dave

[spaceman]

As far as I can see, all models of the Bantam, including the rigid and spring framed models, had the speedo drive on the back wheel.

I don't really know much about the B26 but, if I was trying to fit a back wheel from another bike, the sort of things I would have to compare for both bikes might be:

1. Distance between wheel spindle mounting brackets on frame

2. Sprocket offset from LH spindle mounting bracket

3. Wheel offset from sprocket

I would be happy to try to measure these parameters for a D14 Bantam if that helped but it would not surprise me if some of them varied over the Bantam model range D1-D175?

[Tomlinson]

Thanks for offering to measure.They might be really handy dimensions.I can add/remove spacers.I can also cut off the speedo drive if needed.
I also need to think about chain size.From what I can see my drive sprocket is 1/4 x/5/8 teeth .I have a feeling bantam might be smaller ?
Thanks Dave

[spaceman]

The BSA Bantam used a rear chain size of 1/2 x 3/16 on all models but, in principle, it might be possible to replace ther rear wheel sprocket with one to match 5/8 x 1/4?

I'll have a quick measure of my D14 rear wheel later to provide a reference for you. The speedo drive should not be a problem because it is simple clamped on to the wheel axle and driven via dogs in the drive that engage with cut outs in the hub as per normal BSA practice.

[spaceman]

For my D14 Bantam, the ball park measurements are as follows:

Distance between rear axle frame brackets:  160 mm

Offset of chain from LH frame bracket:  25 mm

Offset of wheel from frame bracket mid point:  10 mm (towards the right)

Hope these numbers help.