1966-1974 BSA A65 Wide Ratio 5 Speed Gearbox

At last here it is…what all A65 owners were hoping for! A 5 speed with smooth modern bike shifting and installation with minimal modification required.

We have designed a 5 speed gearbox which utilizes a completely new selector mechanism to give more positive shift performance, undercut engagement dogs, and is manufactured from high grade motorsport steel for strength and durability. Super finished as standard.

The cases vary in one area depending on year model and as such on some cases next to no modification will be needed. On some earlier models a little more material may need removing from this area, but in either case this can be carried out with a Dremmel. We can supply a dummy fitment tool on request which will indicate how much material will need removing before purchasing the gearbox.

There is a subtle difference in the design of the lever return mechanism on the 62-65 model A65’s. Our current design works with the 1966 onwards models. We will be aiming to manufacture another version to suit the 1962-1965 year models, please enquire if this is of interest.

1st 14 – 26 2.513:1
} 36.4%
} 28.4%
} 12.7%
2nd 22 – 26 1.599:1
3rd 26 – 22 1.145:1
4th 23 – 17 1.000:1
Overall reduction 1st – 4th 60.2%
1st 15 – 25 2.778:1
} 33.7%
} 22.5%
} 18.8%
} 13.8%
2nd 19 – 21 1.842:1
3rd 21 – 18 1.429:1
4th 23 – 16 1.159:1
5th 25 – 15 1.000:1
Drive Ratio 15 – 25 1.667:1
Overall reduction 1st – 5th 64.0%

66-74 BSA A65 Wide Ratio 5 Speed Gearbox

Price £2600.00

+VAT (if applicable) & Carriage.

Nova assembly: 06861-001