Colnago Bets Against the 57mm Tire Trend With the Stretched G5-X

Today, the Colnago G5-X launches with a unique twist on a modern gravel race bike, marking a massive departure from the previous generation. The G4-X still had a foot on the cyclocross course and carried a road-esque feel. Ride it in 2026, and it feels like the perfect all-road bike with its 45mm max tire clearance. This time around, Colnago is looking at the challenge of off-road riding through a brand-new lens.

True gravel geometry

At this point in the history of gravel bikes, a new split has formed. While once there were gravel adventure bikes and gravel race bikes, now we’ve coalesced into a space where everything is both, and the choice comes down to short and steep geometry vs. long, low, and stable geometry.

The previous version of the bike fell into the road-like short and steep geometry, but this time around Colnago is firmly planting its flag in the long, low, and stable camp.

To understand the shift, you have to look at the bottom bracket. The G4-X utilized a 70mm drop, which kept the handling tight but perched the rider relatively high, much like a cyclocross frame. On the G5-X, Colnago increased that drop to 80mm on the smaller sizes and 77.5mm on the larger frames. In some ways this is about tire clearance, but that’s not the whole story. By dropping the bottom bracket nearly a full centimeter, the frame pulls your center of mass down, giving you an “in-the-bike” feel that should help with high-speed stability on loose surfaces.

The brand didn’t stop at the bottom bracket to achieve this composure. Colnago stretched the chainstays from 430mm to 435mm and slackened the head tube angle by half a degree down to 71.0° on the mid-sizes. This pushes the front wheel further out and lengthens the overall wheelbase. The geometry no longer demands constant, twitchy steering corrections. Instead, it is designed to self-center and track straight through washboard gravel and rutted descents without deflecting. The idea is to trade some of the snappy, tight-corner acceleration (which can be nervous depending on the use case) for predictability during ultra-endurance races like Badlands, which Colnago specifically mentioned.

What’s perhaps even more interesting is that these changes don’t come at the expense of fit. The upper part of the geometry, including stack, reach, and seat tube angles, remains almost the same. Clearly, the idea is to create the feel of a race bike while adding stability for rough and fast descents during a race.

Tire clearance, or not?

The one place where we are not seeing much deviation from the norm is when it comes to tire clearance. The standard that seems to be emerging is 57mm, with 50mm being the bare minimum for a modern gravel bike.

The G4-X was a bike that stayed conservative with a max 45mm tire clearance. The update does bring a huge 8mm more clearance, but do the math there. Colnago is launching the latest G5-X with a max clearance of 53mm in a world where many of the fastest gravel race bikes are going quite a bit bigger.

While 53mm is conservative compared to the broader market, it is also a risk. Colnago is essentially drawing a line in the sand, betting that pushing clearance out to 57mm isn’t worth the compromises that come with it. Bigger tires tend to dominate the feel of a bike, and not always for the best. It would seem that Colnago considers 53mm big enough. On the upside, there are no stated limitations for 2x compatibility within that 53mm of clearance, and the max chainring size is 50t.

Race targets dictate the design

The musings about tire clearance are not actually supported by Colnago’s marketing, so it’s not exactly clear why this bike tops out at 53mm of clearance. Another possible reason is that Colnago chose to focus this bike around a series of American-style gravel races all around the world. It would seem that doing the calculations with The Traka, Unbound Gravel, Badlands, and GranGuanche Audax in mind, Colnago thinks 53mm is enough.

Part of those calculations, though, is that you need to carry things. Unlike the G4-X, the G5-X has integrated downtube storage. On top of that, there are the external mounting points to support the ultra-endurance races on that list. The bike features standard top tube mounts for a bento box (with a cover just like the G4-X), plus new mounts positioned under the downtube and on the fork legs. Colnago specifically added these to address the realities of events like Badlands and GranGuanche Audax, where sleeping out is unavoidable and riders need the ability to haul extra cargo, sleeping gear, and heavy water loads over multi-day stretches.

Another interesting choice is that every G5-X ships with three Fidlock Twist mounts. While it is still possible to use standard bottle cages, anyone who’s ever dealt with frame bags will understand the necessity of managing bottles packed into what space is left. The Fidlock design makes getting bottles in and out easier from the side while also eliminating bottle ejections on rough surfaces. The other advantage to Fidlock is more choice for carrying things. The third mount under the downtube might be a good choice for mounting tool cases or storage pods that can also take advantage of the magnetic mounts.

The last detail Colnago added with these races in mind is a switch from the previous D-shaped post to a new round 27.2mm seatpost. One aspect of this is the desire to add compliance through flex in the post, but Colnago also states that it is to allow more choice. Keep it rigid and choose whatever brand you want to fine-tune the flex, or swap to a dropper post for the roughest races.

Pricing and availability

The Colnago G5-X is available today worldwide. Find more info at the Colnago website.