[via Toolmonger]

For fun and practicality, we’ll start with this weed whacker bike. It uses an Echo SRM-210 trimmer motor. The pedals of the bike were replaced with a second sprocket driven by a chain attached to the motor. The bike reportedly does up to 25mph and 100mpg. The nice thing about the these motors is they work no matter what the orientation.

We found another bike assisted by a weed whacker motor, but instead of removing the pedals and powering the gears, this bike simply attaches a 31cc weed whacker with a model plane propeller. The propeller provides thrust, but don’t expect this design to work near as efficiently as the previous one.

If you think we’re cheating by talking about bikes where we should be discussing skates, slow down. Trust us, you’ll really wish you could slow down when you strap on these skates: they pack 25cc motors mounted on the back of the right skate, which achieves speeds of 20mph like the kid in the picture. These are made to order by a Chinese manufacturer, just don’t bother trying to buy a pair in the UK.