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Singles / BSA Gearbox ratios - BSA M33/B33 etc
« on: 18 March, 2022, 13:54:43 »
Hi,
I have a 1955 BSA M33 Plunger. I am trying to workout how to get the most extra MPH out of the old girl. Its got a standard 4 speed gearbox that I rebuilt but didnt think about the internal ratios. Things can improve the speed include.
1. Larger engine sprocket
2. Smaller Gearbox Sprocket
3. Gearbox ratios.
Attached to this message is the 1955 BSA Sales Brochure with the gearbox ratios for both BSA B and BSA M, with and without side cars. Can someone explain how the gearbox ratios relate to the internal gears, number of teeth, and layshaft number of teeth etc. People advertise the 4 speed gearboxes as Goldstar's but may not have the right ratio's
Ideally someone out there will have a standard 4 speed gearbox with higher ratios that the one I have at the moment and might sell me them?
Thanks
I have a 1955 BSA M33 Plunger. I am trying to workout how to get the most extra MPH out of the old girl. Its got a standard 4 speed gearbox that I rebuilt but didnt think about the internal ratios. Things can improve the speed include.
1. Larger engine sprocket
2. Smaller Gearbox Sprocket
3. Gearbox ratios.
Attached to this message is the 1955 BSA Sales Brochure with the gearbox ratios for both BSA B and BSA M, with and without side cars. Can someone explain how the gearbox ratios relate to the internal gears, number of teeth, and layshaft number of teeth etc. People advertise the 4 speed gearboxes as Goldstar's but may not have the right ratio's
Ideally someone out there will have a standard 4 speed gearbox with higher ratios that the one I have at the moment and might sell me them?
Thanks