ok at least it makes sense now - so i really, need to reduce from 7300 to 80rpm over 3 stages, 2 in the reduction box and 1 from the box to the chainring?
If thats the case doesn't that mean i eed like a 91-1 reduction? i wont get that surely?
if the best im going to do is 3-1 at stage 3 (gb to chainring) then matts gb needs 2 x 6-1 reductions is that right?

If thats the case doesn't that mean i eed like a 91-1 reduction? i wont get that surely?
if the best im going to do is 3-1 at stage 3 (gb to chainring) then matts gb needs 2 x 6-1 reductions is that right?