Guess how fast the world’s fastest bicycle goes?

89.59 miles per hour (144.18 km/h.)

This astonishing new record was set in September, at the 2016 World Human Powered Speed Challenge in Nevada. The record holder is a bike called Eta, which is developed by Aerovelo, a Canadian company specializing in designing human-powered vehicles. (They previously designed a human-powered helicopter.) Aerovelo says it cost about $370,000 to build Eta over the past three years. which was covered by funding from many sponsors, most notably, Google.

What makes Eta so fast is primarily its streamlined aerodynamic shape. It’s a universe apart from traditional bikes. This unique shape allows the bike to face minimum resistance from the air, which is the biggest obstacles for cyclists. Although Eta is the fastest, it’s worth noting that it’s not the only “speedbike” that utilizes this shape. There have been a few other speedbikes out there that have a similar design.

It would be cool if one day we could ride bikes like Eta to work or to compete in races like the Tour de France. But unfortunately, that’s not the focus of speedbike design, at least not for now. A bike like Eta doesn’t actually have much practical use. For example, it’s too heavy to climb hills.

The engineers at Aerovelo are mainly focusing on improving Eta’s speed, to push the limit of human-powered vehicles. But they say, “A bike meant for practical use, designed with some of the lessons learned from Eta, could be a very effective means of personal transportation.”