Although the skates are definitely the cooler choice with their tricks and not changing the BGM, and also because I skate irl, the bike is the way to go for me. Mainly because of the bike's consistent movement.
The bike's speed is constant no matter the pressure applied to the analog stick, and the terrain (aside from the windy conditions on Rt. 13, but that affects both devices anyways). The bike also offers the choice of using the analog stick or the control pad, which I like to switch it up every now and then.