Germany’s famous Nordschleife (“North Loop”) track at the Nürburgring racing complex is hosting a 24-hour endurance race in July, and this time around, its participants won’t be sitting on four wheels.

This year’s Rad Am Ring (“Bike at the ‘Ring”) race, sponsored by German engineering giant Bosch, offers teams of bicycle racers the opportunity to test the limits of their bodies and their bikes while also chasing the glory of victory at what is sure to be the world’s most challenging ebike race.

Teams have multiple riders that take turns racing around the track a few hours at a time in order to keep up the pace for the full 24 hours, and also have support crews on-site in order to make adjustments to the bikes (brakes and brake pads, primarily) during a few quick pit-stops. The winner of each class is the team whose bike notches the most laps.

At 2014’s Rad am Ring, the first year to allow ebike entrants, Bosch eBike Racing Team 1 won the ebike class after 34 laps of the Ring in just over 24 hours, averaging 22.7 MPH during the entire race, with Team Riese + Müller and another Bosch team following closely behind. The fastest non-electric bike team was able to complete 32 laps in 24 hours, meaning that the ebike teams were only 16 to 32 miles ahead of their non-electric counterparts after 24 hours. The fastest lap time for an ebike at last year’s race was 39:16 (24.5 MPH average lap speed), approximately 5 times slower than the race cars that lap the ‘Ring in 6 to 9 minutes, and the highest speed recorded by an ebike at the race was 59 mph, surely on a downhill section.

The ebikes likely would have lapped the ring much faster if their assist hadn’t been limited to 25 KPH. As a result of the limits on electric assist, the ebikes’ advantage over their non-electric counterparts was mostly limited to climbing steep hills, and in fact, the ebike course was slightly different than the non-electric race course and included one section with a 27% incline meant to serve as a special challenge to the ebike riders.

This year’s Rad am Ring will take place from July 24th-26th. More information is available on their website.