Is it the fastest gravel bike in the world?

There was a lot to see at Unbound gravel racing at Emporia, Kansas, this year.

With a record 4,000 registered riders in attendance along with their support crew, family, friends and cycling fans, the small town in the middle of the United States has earned its nickname “Gravel City”.

With such a concentration of potential consumers in one place, hundreds of brands took the opportunity to showcase their gravel offerings during a two-day exhibition.

Schwalbe launched its new tires G-One RS tiresthree-time world champion Peter Sagan was there to show Specialized Superlight Crux which debuted last fall, but Ridley, Hunt, Apidura and Fat Pigeon were there to present something entirely different.

The quartet of brands have teamed up to produce what they claim is the fastest gravel bike in the world or rather, a complete gravel race ready setup in which the bags make the bike go faster.

Ridley, Hunt, Apidura and Fat Pigeon Collaborate to Create the World's Fastest Gravel Bike

The bike cuts a slim silhouette, the bags are barely visible.

(Image credit: Anne-Marije Rook // Future)

The “world’s fastest gravel race bike”, even faster

Gravel races tend to be long runs that take place in remote locations. Riders must be autonomous to refuel and repair punctures and mechanics. As such, riders rely on paired hiking or biking bags to carry their food, tools, spares, and other essentials.

But like in all other racing disciplines, the objective is to complete the course as quickly as possible to beat the others to the line.

To that end, we’ve seen the emergence of increasingly lighter race-specific bikes and deeper wheels, the use of aerobars, thin hydration vests and other gear aimed at providing any benefit racing possible, whether in terms of weight or aerodynamics.

While brands like Specialized and Cannondale initially focused on comfort and suspension, Ridley was keen to venture down the road of higher performance through aerodynamics. The Kanzo Fast was released in 2020, which is a gravel adaptation of its Noah aero road bike.

Ridley engineers have spent hours in the wind tunnel and on gravel roads to produce a purebred gravel racer that is highly responsive and faster than any other gravel bike on the market. Yet all that thinness and aerodynamically optimized shapes lose their effectiveness when loaded with bags.

Enter bike Apidura bag specialist. A leader in bikepacking luggage, the British company also wondered if its bikepacking bags could be designed to avoid drag and help cyclists reach their destination faster.

And so into the Bike Valley wind tunnel they went. Early testing by both brands revealed that a poorly optimized bikepacking setup could cost riders up to 17.5 watts at 40 km/h, negating any benefits gained from an aero bike, larger wheels deep or a combination. Even a small pocket of food on the bars could add four watts of drag at 40 km/h.

While not something multi-day bikepackers would worry about, it can make a difference when racing a career like Unbound, Belgian Waffle Race or SBT GRVL.

Could bags be designed to have less drag? Better yet, could they make a bike faster?

Thinking of bike bags in the same way as fairings or airfoils, bags could actually help create a faster overall system.

After six months of development, the “Aero Pack System” was put through its paces with Fat Pigeon’s Nol van Loon in the Bike Valley wind tunnel in Belgium. Uniquely integrated with a full-size Ridley Kanzo Fast bike frame, the bag system consists of a seat, frame bag and top tube bento box.

The top tube bag is the smallest Apidura has ever made and hides in the silhouette of the steerer and stem while providing plenty of space for gels or other small items.

The frame pack is attached using a custom 3D printed bracket to ease the transition from frame to pack, and attaches directly to the frame. Similarly, the seatstay pack also features a custom, frame-specific 3D printed bracket that bolts to the bike’s frame fender mount.

The bags feature a new TPU fabric opening and magnets that not only provide easy access, but are also flush and keep dust and water out.

Even the fabric design of the bag has been aerodynamically optimized. The dotted pattern is not for aesthetics. Instead, this new design was found to be 5.7 watts faster than Apidura’s standard Hexalon fabric at 40 km/h.

The overall result? A saving of 16.66 watts at 40 km/h – this is equivalent to going from shallow wheels to deep aero wheels, or going from street clothes to a suit.

Even at a more realistic endurance speed of 32 km/h, the packs saved 2.4 watts. Adding an Apidura Racing hydration vest to Van Loon’s setup further improved that 7.67 watt saving.

More importantly, these bags had to remain practical so that Van Loon could carry the food, tools and equipment needed to complete the 200-mile (322,000) event, which he did in 11:20:57. s at an average speed of 28.38 km/h. despite the rather epic weather conditions.

Chris Herbert from Apidura said weekly cycling that this was a pure concept project and that the current Aero Pack system will not be for sale as is. However, lessons learned and technology gained will certainly find their way into future products.

Frame: A great Ridley Kanzo Fast

Interior: Integrated stem and handlebars from Ridley (no wires in sight!) and clip-on adapters for PRO aerobars

Band : Shimano GRX

Wheels: Hunt 42 Limitless Gravel wheelset wrapped in Vittoria Terreno Zero tires

Wiley C. Thompson