Jeff Tiedeken understands that the thrill of going downhill on a bicycle is probably the best part of riding a bike. With that in mind, he's built what he's calling the "Gravity Bike" with no pedals or chain, bringing the total weight of the bike down considerably and allowing for the seat to be positioned more like a motorcycle. While these adjustments make it impossible to actually ride the thing in the classic sense, they also allow the bike to reach speeds of up to 50mph, making this less a bicycle and more a downhill throttling device. So, while it may not technically be a bicycle we still think it's pretty awesome. Check it out in the thumbs above.