Cart wheel

A spoked wooden wheel: a turned central hub, spokes driven into it, and a rim made of curved sections called felloes. Rims were often protected with iron strips or nails; the continuous shrunk-on iron tyre is a later development. Later wheelwrights preferred elm for hubs, oak for spokes and ash for felloes; medieval preferences are less well documented. Making wheels was a skilled trade.

Sources: en.wikipedia.org