Originally Posted by joejack951

Both Islabikes and Woom make nice kids' bikes with 14" (~250mm) aluminum rims and real bicycle hubs. Both sell replacement wheels, too. I can't vouch for the width of the Woom rims but the rims on my son's CNOC 14 are roughly 25mm from memory (much skinnier than the 37mm tires mounted on them). If my newborn wasn't sleeping on my chest right now I'd go take a caliper measurement for you. And I can always do it later if you are interested.