The big 32 Inch MTB Test

We pitted the ride-ready 32-inch hardtail against the 29er standard—using timing gates, power-meter data, and acceleration sensors. The result was clear-cut, and still caught us off guard.

We didn’t just weigh our test bikes complete—we also put the relevant individual parts on the scale. It’s important to be clear about the numbers we found: this is absolute high-end cross-country territory. Even in the 32-inch setup, the hardtail still comes in super light at under 9.5 kg. For comparison, the Orbea Oiz, which we’re running as a side reference, weighs 2 kg more despite a very premium build kit.

What surprised us: the 32-inch tire only weighed 30 g more than the 29-inch counterpart with the same width, same casing, and the same tread. On paper, the weight penalty should be bigger. Whether that low weight comes down to production variance or a deliberate maxxis design choice, we can’t say. We only weighed a single tire pair as a sample.

The main argument against bigger wheels is always rotational mass. More inertia equals slower snap out of the gate—that’s the common theory. We validated this on our own rotational test rig. A weight on a string spins up a shaft, with the wheelset being measured hanging off it.

Based on the time it takes the weight to unwind, you can use a physics formula to calculate the moment of inertia. The test setup is also described again at this link in section 2.2. The timing runs were recorded with a photogate so they were 100% comparable.

The bare numbers seem to back up the skeptics at first: a 32-inch wheel has a 33% higher moment of inertia (0.16 vs. 0.12 kgm²). To illustrate what it would take to bring a 29-inch wheel up to the same inertia as the 32-inch wheel, we had to add an extra 355 g of weight at the rim. But pure inertia is only half the story.

The key flaw in the thinking behind many of these comparisons is ignoring the rollout distance. At the same riding speed, a 32″ wheel spins slower than a 29er. If you look at the physics equation for accelerating a wheel in forward motion, the radius actually cancels out of the formula. When you factor that into the energy balance, the calculated disadvantage when accelerating shrinks significantly:

No one disputes that bigger wheels feel a bit more sluggish. But because their larger circumference means they don’t have to spin up as fast at the same trail speed—so they run a significantly lower angular velocity—the effect pretty much cancels itself out. What still makes the snap off the line feel a touch more lethargic is simply the extra weight you’re hauling around with the bigger wheelset. But that penalty is a lot smaller than you’d expect—at least in the high-end segment.

Bigger wheels have a shallower rollover angle when you’re smashing through obstacles. In theory, that translates to lower forces and less rider fatigue when you’re, for example, plowing through roots. To measure how big that effect really is, we analyzed a standardized root section using acceleration sensors (Phyphox measurement on the top tube).

We ran each bike through the test section 10 times, and for our conclusions we always used the average values from our test runs.

The analysis of our hardtail test runs shows that the 32-inch wheel does a better job of damping trail chatter. The theoretical effect is clearly measurable out on the trail. To get a solid read on the data, we looked not only at peak impact harshness, but also at the total accumulated hits over the test window and the variance of the impacts.

While the maximum impact peaks on the 32-inch bike dropped by just 2% compared to the 29er hardtail, the total sum of vibrations dropped by a more noticeable 5%. Over the course of a full ride, that should translate to less upper-body fatigue. The variance of the measured values also drops by 2% with the bigger wheels.

This number indicates how much the readings swing from one extreme to the other. A higher variance value automatically means a lot of chassis chatter in the bike and therefore a slightly more out-of-control ride. So the 32-inch bike tracks calmer, because it doesn’t “fall” as deep into holes between roots and has a smaller rollover angle than a 29er.

The comparison numbers for the two hardtails are pretty clear-cut. The 32-inch hardtail is more comfortable and offers more control. That naturally raises the follow-up question: Can the big wheel replace a full-suspension setup? That’s why we ran the same test protocol on the Orbea Oiz as well, and the data makes it crystal clear: no.

A modern 120 mm full-suspension bike (Orbea Oiz) is in a different league:

While a 32-inch hardtail can’t match the comfort of a full-suspension bike’s kinematics, the timing gate in the same test setup delivered an unexpected result: across 30 runs, the 32er hardtail was the fastest bike in the test—it beat the 29er full-suspension bike by 3% and even the classic 29er hardtail by 4%. That proves that comfort and speed on rough terrain aren’t necessarily the same thing.

That win doesn’t mean hardtails have an across-the-board advantage, though—it mainly comes down to the superior rollover of those massive wheels. Because the 32-inch wheel hits obstacles at a shallower angle and doesn’t drop as deep into holes, it carries momentum better. While the full-suspension bike’s suspension is doing the work, the 32er is simply leveraging its bigger hoops to conserve speed more efficiently through that specific section.

Gray is theory—what counts is how it rides on the trail. On a 1.5 km loop with five sectors (uphill, flow downhill, gravel, roots, tech singletrack), the two wheel concepts went head-to-head.

To keep the real-world test from turning into an apples-to-oranges comparison, we used power-meter pedals to verify that rider input stayed consistent on the climb and flat sections. On the descent, the trade-off was one rule for the test riders: coast only—no pedaling. That way, the difference between the wheelsets is comparable, not the difference in the riders’ power output.

Despite the extra 440 g of wheel weight, we couldn’t measure any time penalty on the climb with 32-inch wheels. Power numbers and lap times from two test riders over six laps were identical to the 29er setup. Apparently, the improved traction and smoother rollover on forest loam offset the higher mass. The full-suspension bike, which was over 2 kg heavier, was measurably slower on this test segment with 65 meters of elevation gain.

The results are similar on a flowy downhill without roots and on gravel. In these sections, the trend only leans so minimally toward 32-inch that you can’t really call it a clear-cut advantage. Things change once roots come into play.

In rooty, technical sections, the 32-inch bike really came into its own, and the stopwatch results backed that up loud and clear.

In the rooty sections, the 32-inch hardtail wasn’t quite—but almost—on par with the comparison full-suspension bike.

Bottom line from our real-world test: there wasn’t a single sector where the 32-inch bike had a measurable disadvantage. But in the sectors where roots came into play, it clearly had a time advantage over the 29-inch bike—just not in a game-changing magnitude.