[Doug]

Ok, here is the deal on the Cartrix W196 Mercedes.

Front wheel:

16.7 mm overall wheel diameter
5.7 mm width
3 mm ridge width
14.2 mm rim diameter (visible)

21.5 mm overall tyre diameter
7 mm width
3.7 mm wall height

Rear wheel:

16.7 mm overall wheel diameter
5.7 mm width
3 mm ridge width
14.2 mm rim diameter (visible)

22.5 mm overall tyre diameter
8.4 mm width
4.2 mm wall height

Hope it helps