As above, I've been looking around for gear knobs for my Indy but the shaft is 20mm and the max I've seen I think is 16mm. Ideally I want a Z-cars style one, any ideas??

Hi, you could try MAC#1 or alternatively see if you can find a local machine shop and get them to turn one for you.

Simon

My what a big shaft you have!

Now the entendres are out of the way, how about....

Using a nice bike handlebar grip, not shiney Z cars but I reckon something like this would look quite cool?

http://www.halfords.com/webapp/wcs/stores/servlet/ProductDisplay?catalogId=10151&storeId=10001&partNumber=232744&langId=-1&source=td