[dale]

Originally Posted by Chequered Flag Racing

hopefully this correct

Bearing in mm is 8x12x3.5

http://www.tamiya-store.com/shop/tamiya/1280/sealed/bearing/3piece-p-4305.html

Are the kawada / Ansmann spurs metric hole centres or do they use 12th pan car bearing size?

That's the correct bearing. My spurs were all 70t; that gave a really good range of gearings.

Most other spurs (apart from tamiya ones) have the imperial centre hole so won't take a bearing.