If any one has not seen them yet there is a german company making Alloy rims for the Microsizers. These rims should work in your ZipZap after taking apart your front and rear axels. There is another forum talking about the rims at a place called Bitpimps. If you are new to that hood remember your bulletproof vest.
http://bitpimps.lixlink.com/pages/ph...er=asc&start=0
Some Examples
WT03
BBS Zentral Ø 10.8 mm
WT04
BBS Zentral Ø 10.6 mm
WT46
BBS Racing 18 Zoll Ø 11.5 mm
WT56
BBS Zentral Ø 10.8 mm
More pictures of these rims can be found at
http://www.scala43.com/scala43/rad.htm
The size is the rim size not tire and rim and the size of the blue zipzap gear is .403" or 10.24mm so choose rims that will work.
See you over at Bitpimps.