80 mph on a Hand-made Bicycle.

London-based framebuilder Tom Donhou has managed 80 mph on a hand-made bicycle on the open road — though indoor tests ultimately revealed his bike was capable of reaching 102 mph.

Donhou's bike is a custom-engineered contraption that he assembled with the help of a few friends, all for the purpose of showcasing the value of backyard engineering. And, of course, for making a bike go really fast. By comparison, the average person on a normal bike would probably have to push it to reach speeds around 25 mph.

In order to get his bike up to super speed, Donhou added an oversized chainring, adding significant power to the pedaler. It features 104 teeth, compared to the 20 to 50 you'd find on a normal bike. Donhou also sought more stability by positioning the chainring lower to the ground, and lowering the handlebars.