Bikes also have wheels, which consist of tyres on rims.

Ditto for cars.

Far be it from me to start a pedantry flamewar, on the Empeg BBS of all places, but I think Chuck's point was that bicycle wheels usually consist of (theoretically) separately-replaceable rims, spokes, and hubs, whereas car wheels are usually one-piece. However, exceptions do exist on both sides. And personally, I'd not count tyres as being part of the wheel -- but then Zen And The Art Of Bicycle Maintenance reminds us that the bicycle is One and any division of it is a human construction anyway...

Peter