Gravel bikes wind tunnel tested: How does the new Specialized Crux stack up against the Argon 18 Anti Matter, Wilier Rave, Lauf Seigla, and more?

Ten years ago, gravel bikes didn’t know what they were. Some were bikepacking bikes, others mountain bikes with drop bars, others cyclo-cross bikes with new titles, and others were just a blended mix of everything.

But as races have grown in prominence and prize money has increased, competitors have become more… well, competitive. Flannel shirts and post-ride beers have been replaced by ice vests and high-carb recovery drinks. Talk of handlebar moustaches has been replaced by talk of handlebar width. And tyre width is everyone’s favourite subject, from the amateur ranks right through to the pros.

As all that has changed, bike brands have scrambled to keep up, with riders wanting bigger tyre clearance, aero frames, narrow handlebars and more. And as a result, a new category of gravel race bike has formed.

I’ve long been curious which of these new bikes is most aero, and I strongly suspect our readers are too, but there’s a big caveat that’s stopped us testing it ’til now: tyre clearance.

The term ‘faster’ doesn’t solely come down to a bike’s aero drag, and that’s especially true on the rougher surfaces of gravel. A bike could have 40mm tyre clearance, be incredibly aerodynamic, but really slow on balance once you’ve factored in the rolling resistance against a bike with 57mm clearance.

We’ve long understood that wider tyres offer lower rolling resistance, but it wasn’t until earlier this year, when we published a test that measured the combined differences of rolling and aero drag across different widths, that we could put some numbers against it.

We’ve got more tests planned in that field to refine our data and improve its accuracy. But for now, we’re in a position to confidently measure the aero drag of gravel bikes with that context in mind. So that’s what we did.

Just as with our road bike wind tunnel tests, we’ve taken a cohort of gravel race bikes to the wind tunnel at Silverstone Sports Engineering Hub to put them to the test.