Because who likes changing gears to make climbing hills easier anyways, this is a video of Sergii Gordieiev of Youtube channel The Q replacing a bicycle chain with a series of 3D printed gears, effectively making it a single speed. So is that an upgrade or a downgrade? I suppose that depends on who you ask, but if you ask me life is a lot like learning to ride a bike: you fall and get hurt a lot while your neighbors laugh and throw empty beer cans.