| Diagram | Fig. 16 — REAR WHEEL · ref 52 |
| Subsystem | wheels |
| Listed in parts books | 1969–1970 |
BSA Speedometer gearbox—2 to 1 ratio (BG.5330/31)
A 2 to 1 ratio speedometer drive gearbox for the rear wheel, cataloged as BG.5330/31.
This is the speedometer gearbox that carries a 2 to 1 ratio, cataloged under BG.5330/31. It shows up in the rear wheel figures, which is where the drive for the speedo cable is taken off the wheel on these machines.
Read more
The gearbox translates wheel rotation into the right speed for the cable running up to the speedometer head. Getting the ratio wrong means a speedo that reads high or low, so if you're chasing a speedometer that's off, this is one of the parts worth checking.
Our catalog record ties this to appearances across 1969 and 1970 rear wheel listings. We don't have more detail beyond that, so confirm fitment against your own rear wheel setup before ordering.
We've never carried this one. Tell us what you're after and we'll go looking — you'll get a price and photos before you commit to anything.
Sorry if we got something wrong here. If you think this information isn't correct, .