Originally Posted by
RWD_cossie_wil
But you lose the entire reason for doing the conversion then, the lovelly sequential gearbox!

No, you get the best of both worlds
You can leave the sequential box in a suitable gear and use the car box for day to day stuff / reverse.
Also you can stick the car box in a suitable gear and then use the sequential box if you fancy a thrash or a track day.
You would have 30 forward gears and 6 reverse

You would need to sort out a solenoid paddle shift or extra lever for the bike box and there would be extra frictional losses running two boxes.