[JMay]

Kevan,

Front tyre is 8mm wide and radiused plus by careful setting of the guide height with braid the wheel is just touching if you push the front down against the braid so no problems on jamming in the slot. The prototype is now in bits awaiting modified parts, so no pics yet but running the mark 1 around Carrera track the only issue is the obvious one of a very high C of G causing toppling on sharp radii corners so will add weight to stabilise on the next iteration. 

Cheers
           JMay