3T Exploro Ultra Review: A Fast Gravel Bike Built for Big Tyres

Introduction

Some gravel bikes are built to be quick on smooth surfaces, and others are built to survive rough terrain. The 3T Exploro Ultra is an attempt to do both at once, by taking the aerodynamic carbon platform that 3T has refined over several generations and tuning it around much wider tyres than most gravel bikes use.

That sounds like a small change. It is not. The Ultra can accept proper mountain bike tyres, which opens up rocky, loose and genuinely rough ground that would normally be out of reach for a gravel bike. Yet the ride character stays close to a road bike. That combination is difficult to find elsewhere, and it is the entire point of this bike.

To put the concept under real pressure, the bike was taken up a 1,085 m summit in Snowdonia, climbing a mix of tarmac, steep gravel and loose rocky trail before a long descent back down. That outing makes the Ultra’s strengths and its limits fairly clear.

Who This Bike Is For

The Exploro Ultra makes the most sense for riders whose local terrain mixes smooth tarmac with rough tracks. 3T’s own reasoning is straightforward: most riders live in urban areas and end up riding a mixture of surfaces, so a bike that is fast on easy ground and capable on hard ground removes the need to choose between two machines.

If your riding is almost entirely smooth road, a dedicated road bike will still be lighter and quicker. If your riding is almost entirely very rough and rocky, a mountain bike remains the more sensible tool. The Ultra sits in the space between those two extremes, and for a great many riders that space is where most real riding happens.

It also suits riders who want to reshape one bike rather than own several. Because the platform accepts both 650b and 700c wheels, and both single and double chainring setups, the bike can be pointed at very different kinds of riding without changing frames.

Main Strengths

The Ultra is an evolution of the Exploro Race Max, and the changes are concentrated on how the bike behaves when it is running big tyres. Aerodynamics, geometry and clearance have all been adjusted around that use case, while the carbon construction and the drivetrain flexibility carry over from the Exploros that came before.

A Road Bike Feel With Off-Road Capability

The most striking thing about the Ultra is how little it feels like a compromise when the terrain turns rough. Despite the volume of tyre it can carry, it keeps the sharp, direct handling that has defined the Exploro line, and it still feels quick on tarmac. That road-like quality is not an accident. 3T deliberately honed the geometry to hit a handling sweet spot with wide tyres, so the bike is designed to spend more of its time in that configuration rather than being built primarily around narrow 700c wheels.

Lightweight Carbon Frame and Wide Tyre Clearance

Weight is where the Ultra separates itself most clearly from a mountain bike. The frame is quoted at 980 g in a medium, and a complete build came in under 9 kg even with large, burly tyres fitted. On a long climb that difference is obvious: the bike is light enough to be lifted over obstacles and carried through sections that are too steep or loose to ride, and it still accelerates hard the moment the ground allows.

Clearance for wide rubber is what makes those tyres usable in the first place. The Exploro Race Max had already increased clearance to 61 mm on 650b wheels, and the Ultra develops the idea further with aerodynamics and geometry tuned around wider tyres, while remaining perfectly capable of running 700c wheels. The result is a frame that can take rubber most gravel bikes simply cannot fit.

One Bike, Multiple Setups

Because the bike accepts both wheel sizes and either a single or a double chainring, it can be reshaped around the ride you have planned. Fit narrower wheels and faster rubber and it behaves like a quick road bike. Keep the wide tyres on and it becomes a race-ready gravel machine. That flexibility is central to the case for owning one bike instead of two.

Things to Consider Before Buying

Capability has limits, and it is worth being honest about them. On the roughest part of the climb, with steep, loose and rocky ground, the bike had to be carried. That is less a failure of the design than the nature of the terrain. The ride made it clear that ground of that severity would be uncomfortable and unwise on tyres narrower than around 50 mm, and a mountain bike with suspension would handle it more easily.

The trade-off is deliberate. The Ultra is not trying to be a mountain bike, and 3T is direct about that: if your riding is exclusively extreme terrain, a mountain bike is the better answer. The Ultra earns its place by also being genuinely good on paved surfaces, which is what makes it usable as an everyday bike rather than a specialist toy.

Where a Mountain Bike Still Wins

Steep, loose, rocky descents and sustained technical ground remain the domain of suspension and high-volume, low-pressure tyres. Expect to walk sections that a mountain bike would ride, particularly when gradient and surface combine badly. The reward is that everything else on the ride feels fast by comparison.

Tyre Choice Matters

The character of the bike changes with the rubber you fit. Wide tyres unlock the rough ground but add weight and drag, while narrower gravel tyres sharpen the response on smoother surfaces. Because the frame takes both 650b and 700c wheels, it is worth thinking carefully about the surfaces you actually ride most before settling on a setup.

Buying Advice

If you want a single bike that handles tarmac quickly and can still take on rough gravel and rocky tracks, the Exploro Ultra is a strong candidate. Its mix of a light carbon frame, mountain bike tyre clearance and road-like handling is genuinely uncommon, and it holds up in real conditions rather than only on paper.

Before buying, match the bike to your terrain. Riders whose routes are mostly smooth gravel, lanes and road will get the most from it, because that is where the aerodynamic platform and low weight pay off most clearly. Riders who spend most of their time on very technical, steep and rocky ground will find a mountain bike easier to live with day to day.

It is also worth treating the tyre and wheel setup as part of the decision rather than an afterthought. The Ultra is at its best with wide tyres fitted, and the wheels you choose will shape how the bike feels far more than on a conventional gravel frame.

Conclusion

The Exploro Ultra does one specific thing very well: it lets a gravel bike go places gravel bikes normally do not, without giving up the speed and feel that make them enjoyable on easier ground. The 980 g frame and sub-9 kg build keep it light enough to carry when the terrain demands it, and the wide tyre clearance means the rough sections are genuinely rideable most of the time. It is not a mountain bike replacement, and it does not pretend to be. For riders who regularly mix surfaces, that balance is exactly the point.