Hi Andy,

Thanks for your detailed reply regarding the gearchange mechanism on the Speedy Tiger. I had another look at this box of tricks last night and the operation is still baffling me. The two main gear wheels both turn together and as the gears on the clutch bell are definately fixed I can't see how the drive is changed between gears. I have looked through the slot in the small gear and found what looks like a threaded hole that should house a grub screw but looking through my magnifying glass the grub screw has gone AWOL.
I like to fully understand how things work and it looks as though I will have to strip the gearbox down to fully appreciate how it interacts. If this grub screw is missing it would explain why my Tiger changes up so quickly wouldn't it?
Thanks once again for your advice, it's very helpful to exchange info with other enthusiasts.

Ta,

Chadz [8D]