EXPLORO ULTRA: UNSTOPPABLE Watch the video Back to the Exploro start page

If you’re like us, you love riding in rough terrain but live in a more urban jungle. So you need a bike that is fast on-road and capable off-road.

The Ultra is our most extreme bike, starting out the design process with 55-61mm wide tires. We then designed the whole aero package around those to keep the on-road speed high. If you ride on less extreme terrain, you can also fit 700c tires up to 45mm WAM (With As Measured) on the Ultra.

If you’re looking for a bike that is even further optimized for speed with narrower tires (35-42mm WAM), then the Exploro RaceMax is your perfect match.

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.

The Ultra was our most difficult aerodynamic challenge to date. Start with massive 55-61mm tires and then make the bike aero. There’s nothing we can do about the tires, they’re big and the knobs don’t help. What we can do is take the airflow mess that comes off the front wheel and try to catch and redirect it. That’s why you will see the 60mm wide downtube placed closely behind the front wheel, going even wider as it gets closer to the BB. 

Blending this into the headtube with an off-center aero profile along with loads of other tricks gives you a bike that feels so much faster than your brain can compute. Because let’s be honest, when you see those tires, your brain gets ready for that slow, boring paved performance of a mountain bike. But thanks to your riding position, the aerodynamics, the BB stiffness and the narrow Q-factor, the Ultra actually feels 100% like a road bike when you want to go fast. Even when muddy.

The RaceMax frameset is is fastest with 35-42mm WAM tires. That’s when its top speed rivals the best road bikes out there. So whether you’re on asphalt, easy or tougher gravel, you can be sure you have the fastest setup. But depending on where you ride and how fast you ride, you may want an even bigger tire for ultimate traction and control. Good news: 90% of the aerodynamic advantage of the RaceMax frameset still works with tires up to 61mm WAM.

In a way, the Ultra is the reverse. It is aerodynamically optimized for 55-61mm WAM tires thanks to its wider downtube near the front tire. This extra width better redirects the air coming off a bigger front tire. If you prefer a smaller tire, you can run a 700c tire up to a 46mm WAM. But as you go to a smaller tire, the Racemax becomes the faster choice again. In addition, the Ultra combines its aero seattube with a round seatpost so you can fit a standard, dropper or suspension post.