In further PowerFrame RPG vehicle work, I've pretty much written up the details for skates, skis, surf/snowboards, a variety of pushbikes, and also horse-drawn vehicles such as carts and wagons.
Skates/boards and pushbikes give the user a new Movement Rate based on one of their Abilities - Acrobatics or Bike. Although movement is potentially much faster than walking, you can't just change direction on the spot or necessarily come to a dead stop safely if you're travelling at speed. Another major factor for all these vehicles is the gradient. They are slower going uphill, and faster downhill. I haven't bothered creating a detailed range of grades - up, down, or flat is enough.
Carts and wagons are drawn by animals (or, in the case of hand carts, people). I know most people ignore encumbrance rules, but PowerFrame has a fairly simplified system. Wheeled vehicles reduce the effective weight of carried items, and pulling too much stuff reduces your speed of travel. While you can just quick-reckon it, when it's important you can figure out exactly how fast a pair of horses can pull your fully-laden wagon.
Still to come: motorised ground vehicles, sailing and motor boats, and aeroplanes!