Colnago G4-X SRAM Red eTap AXS first ride review

Colnago has made some small, but significant, changes to its gravel race bike. 

The G4-X features 45mm of tyre clearance and an integrated front end. This, along with plenty of frame stiffness, makes it a fast gravel race bike that takes flowing corners with poise.

Head to my news story for a full rundown of the new bike, as well as details on pricing and an overview of the range.

My initial impressions are of a dedicated gravel race bike that is best ridden fast. However, Colnago’s drive to make this a super-stiff machine might have compromised it for anything other than gravel racing.

Colnago G4-X SRAM Red eTap AXS first impressions

Line up the G4-X next to the G3-X it replaces and the differences are hard to spot. There’s the integration of the cable routing, creating a clean front end, but this still looks very much like a road bike.

In fact, aside from a couple of single-millimetre changes, the geometry is identical to the previous bike.

However, Colnago says it has reworked the chainstays to boost tyre clearance from 42mm to 45mm. 

This, and a brand new Wide version of Colnago’s CC.01 bar, represent the main changes you’ll find on the G4-X.

Colnago G4-X SRAM Red eTap AXS build

Colnago provided me with a top-spec SRAM Red eTap AXS XPLR build. 

That feels like a slightly cruel move from Colnago because complete SRAM bikes won’t be available in the UK. Dealers will, however, be able to offer custom builds should you prefer SRAM.

This first ride featured some serious climbs and faster road sections. As it often does, the Red eTap AXS XPLR gearing impressed with plenty of range and accurate shifts.

Also supplied from the SRAM family are the Zipp 303S wheels. Their wide 23mm hookless inner rim width supported the 40mm Pirelli Cinturato tyres well.

The G4-X provides clearance for 45mm tyres, though race bikes such as the Santa Cruz Stigmata and Specialized Crux offer more. On those, you can fit 50mm and 47mm tyres respectively.

Given the rain, I ran tyre pressures of 26psi in the front and 31psi in the rear. 

At the front of my bike sat Colnago’s new CC.01 Wide bar. Sizes are limited to only five stem lengths (80, 90, 100, 110 and 120mm), while the width is set at 400mm at the shifter clamp area and 460mm at the drops.

I like the shorter 72.5mm reach, but the limited bar widths will mean this suits only a small selection of riders.

Behind the stem, you’ll find bolts for a top tube bag. These are recessed into the top tube and covered with a plastic cover. It was rattle-free when riding, if a little plastick-y.

I was also slightly disappointed by the seatpost clamp cover and seatstay protector, which both shifted very easily when manipulated. These remained in place during riding, but both felt a little incongruous on what is – by any measure – a premium bike.

At $9,750 / €8,870, it isn’t what I’d call ‘affordable’, but it does compare well to Specialized’s similarly equipped S-Works Crux at $12,250 / €11,500.

Along with three SRAM builds, the G4-X is available with Shimano’s GRX RX820 in both 1x and 2x forms (£4,500 / $4,750 / €4,330). Surprisingly for an Italian brand, Campagnolo’s 13-speed Ekar gravel groupset isn’t available.

Colango G4-X first ride impressions

This first ride review is based on a 23km ride in the hills around Girona in Spain, almost all of which was off-road. That's a very short ride, but it was punctuated with many stops for position adjustments and photo opportunities. 

Girona treated me to biblical rain, which wasn’t what I had in mind. However, the British winter has prepared me well for this and, after six months of rainy rides, I was quickly happy to focus on the bike, rather than my squelching shoes and soggy bottom.

The G4-X behaves very much like a road race bike. 

Descending felt as good as wet Spanish lanes would ever allow. The low front end and relatively long reach mean sweeping corners can be taken at a good pace and I found myself stringing together several apexes. 

Gnarlier descents are less suited to the G4-X’s capabilities and here my weight balance felt a little too far forward.

The stiffness in the frame was also very evident when guiding the bike over the numerous drainage ditches that run across the gravel roads. Hitting these sent significant shocks through my hands and feet. 

But this is a pure gravel race bike and the rougher surfaces on this ride were, I believe, a little too much for the bike.

This stiffness is more useful on smoother gravel, steep climbs and fast road sections where the power can be laid down. 

Out of the steep gravel hairpin corners that littered the incredible local climbs, the G4-X felt punchy. These climbs ascend in steps and I was happy to press on to keep my speed up through these steep ramps.

Sprinting from the drops felt very nippy, with the flare of the CC.01 Wide bar offering plenty of leverage. 

I was also very happy with the low-slung riding position when tucking down on the hoods for faster road riding. This is where the G4-X felt most like a road bike and its smooth, efficient speed made these sections fly by.

Tight singletrack sections saw the bike flowing nicely, though I nearly slid out several times as the surface changed from sodden sand to polished stone and back to loose gravel. 

Despite some sketchy moments, the Pirelli Cinturato tyres performed admirably, with the low-profile shoulder tread fighting to find grip.

On smooth, fast sections, the almost-slick central tread contributed to the speedy ride feel. However, these are dry-weather tyres and I would have preferred something with more bite for the conditions at hand.

Colnago G4-X initial verdict

On the right gravel – smooth and fast – the G4-X seems great fun to ride for those who want a racing machine.

It's a pretty bike to look at, with a lovely mix of smooth lines and small edges. Importantly, it’ll also go like a rocket if you want it to. 

My only concern, for now, is the super-stiff frame, which leaves the bike a little one-dimensional, and arguably over-focused on racing to be a suitable option for the wide-ranging terrain gravel riding can present.

A full review, in time, will reveal all.