I have a 16 tooth engine sprocket and 15 tooth gearbox supplied by D & C Classics
48 teeth on cub rear. using 520 Standard chain. heavy chain catches on the gearbox casing. gear ratios STD.
I have a 3ta trials bike and fit a 16 tooth engine sprocket from D&C Classics 01535 630137
14tooth gearbox and 54 rear and use standard 520 size rear chain. TALON will supply a rear
sprocket machined to your dimensions. I fit two rim locks.
Hope this helps.