Racemax Boost - the fastest gravel bike, only faster Watch the video Back to the Boost start page

Review after review and award after award raves about the light, responsive & fun ride of the Exploro Racemax. So when it came time to make an e-bike version, we didn’t want to change anything: same geometry, same aero tube shapes, same agile steering.

But thanks to the e-bike system that hides inside, you have some extra power at your fingertips. Take that detour, climb that mountain or simply have a "no-sweat commute" to work and a great workout on the way home.

We love riding our Racemax into the unknown. Every mountain peak conquered is the result of your own effort. Still, we sometimes wonder what lies beyond that last peak and the extra Boost helps us find out.

Others may love to ride with a group of friends but don’t want them to wait up at the top of the climbs. A little extra Boost lets you arrive all together.

Or maybe you love to commute to work but want to arrive fresh. The Boost lets you get to the office without a sweat and enjoy an adventurous workout on the way home (after all that’s a lot more time-efficient than driving and having to hit the gym afterwards).

To make the fastest possible gravel bike, you need to start with the tire. Tire choice determines comfort & grip. But it also determines how you can shape the frame to redirect the airflow.

To aerodynamically engineer the frame around the tires, you need to know what their REAL measurements are. Not what’s on the label, but how they really fit. That’s REALFAST aerodynamics. But it’s not easy, as the tire dimension depends on the rim you use, the pressure and of course how accurate the manufacturer’s claimed size is.

So we took hundreds of measurements to know the real tire widths (which we call WAM - Width As Measured and RAM - Radius As Measured) and use that to engineer the frame around.

Max clearance information can be found here

Starting from our favorite tires, we then engineered a perfectly fitting rear wheel cutout (with mud clearance of course) and a closely trailing downtube to catch the airflow coming off the front tire. We added a super-narrow headtube (yet with a big steerer inside it), a multi-shape fork and aero details from seatstay to seatpost and from the shielded water bottle to the direct-attachment brake mounts.

Most importantly, we engineered this for realistic riding speeds, wind speeds, tire widths, bottle positions and even for mud. We don’t care if it is theoretically fast in the windtunnel with a fantasy spec. We care if it is fast the way you ride it in real world conditions.