The speedometer drive lock ring is important as it is the adaptor from the rear hub that drives the speedometer gearbox. Fitment is appropriate for
- BSA A65, A70 A75,B25, B50 1971-1972
- Triumph TR6, T120 1971-1972
- Triumph TR7, T140 1973-1974
- Triumph T150 1971-1974
The speedometer drive ring is a threaded adaptor that is fitted to the rear hub on the right-side. There are two notches that locate the speedometer drive gearbox, and it rotates with the rear wheel, driving the speedometer gearbox. Made in the UK by LF Harris.