As soon as a trending number is identified, it gets pushed to the limit. Whether it makes sense or not often doesn’t matter. Only when reality strikes – with confused customers, missing spare parts and incompatible “standards” – does reason slowly return. But by that point, the damage is usually already done.
And now? Are we seeing another market bubble forming with the new 32-inch wheels?Or are we witnessing a real revolution that will fundamentally change our bikes? Will we all soon be riding 32”?
A brief history of wheel evolution
Until the mid-2000s, the MTB world was still fairly straightforward: 26” wheels were once the gold standard. But with the rise of 29-inch wheels in the XC-race segment, things began to shift – initially, mostly on hardtails. By the end of the decade, the first full-suspension bikes with big wheels followed. However, their geometries were often unrefined, tire clearance was limited, components weren’t convincing – and the MTB scene wasn’t quite ready to embrace the new look.
This led to a countertrend: 27.5” wheels entered the picture – closer to 26 than 29 inches. For a short time, it looked like this middle ground would win out. But with the disappearance of the front derailleur, the adoption of sensible thru-axle standards, the refinement of modern geometries and the clear advantages of bigger wheels, 29” ultimately took over – especially on bikes with up to 160 mm of travel.
Today, 27.5-inch wheels are practically only found at the rear, particularly on bikes with more than 160 mm of travel. The reason: smaller wheels provide more clearance between the tire, seat tube and saddle. This allows for more freedom of movement and prevents the rear end from buzzing the tire under full compression with lots of travel. For a long time, oversized wheels were the domain of custom builders serving very tall riders – like US brand DirtySixer, which builds bikes for NBA players.
A curious milestone in MTB history: on April 1, 2016, FOCUS Bikes presented the “BIG BIRD 36” – an April Fools’ joke that got plenty of attention. The concept likely drew on wheels from the unicycle world, where 36” rims have been in use since the early 2000s, and 32” formats have existed since the 2010s.In the past two years, the topic has gained momentum in the industry. The first 32-inch prototypes have been in use since 2025. Among the brands experimenting with the format: BMC, Bike Ahead, KTM, STOLL Bikes and engineering firm Faction Bike Studio. So far, these have been almost exclusively cross-country bikes.
What are the actual dimensions we’re talking about?
With the larger wheel diameter, the outer circumference grows by around ten percent from 29 to 32 inches. t’s worth noting that the inch measurement in this context is only an approximate value, as it refers to the outer diameter of the tire – which varies depending on the internal rim width and, of course, air pressure. That’s why it’s more meaningful to compare dimensions based on the tire’s inner diameter. This is standardised according to ETRTO and refers to the diameter at the point where the tire sits on the rim.
Here’s an overview showing the increase in tire inner diameter from one wheel size to the next:
Interestingly, the jump from 26 to 27.5 inches is smaller than the step from 27.5 to 29 inches. The next leap – from 29 to 32 inches – would be significantly larger again and roughly equals the total increase from 26 to 29 inches. The same applies to weight: the new MAXXIS Aspen 32 × 2.4″ reportedly weighs 830 grams – around 70 grams more than the 29″ version. The weight difference in the wheels themselves is likely similar: rims and spokes weigh about ten percent more.
The theory: Acceleration, rollover behaviour, contact patch and more
Acceleration and deceleration
A 32″ wheel is heavier than a 29″ wheel, and its mass sits further from the axle. This means that it takes more force to speed it up or slow it down. Since the radius contributes quadratically to the moment of inertia, resistance increases sharply with size. To achieve the same braking performance, larger brake rotors are required, too. On the trail, this translates as follows: the larger wheel accelerates more slowly, but retains momentum better when going downhill – even when pumping through rollers. Depending on your riding style and terrain, that can be either a pro or a con.
Additionally, the greater rotating mass generates stronger gyroscopic forces. These forces stabilise the bike’s direction of travel and make it track straighter and more calmly at high speeds – a definite plus on fast descents and rough terrain. On the flip side, the increased gyroscopic effect makes quick changes of direction harder and steering more sluggish, requiring a more active riding style.
Rollover behaviour
Bigger wheels roll over obstacles more easily. The attack angle becomes shallower, which reduces hang-ups on sharp edges. The result: more comfort and the ability to carry speed better – whether on rough trails or steep climbs.
There’s also the effect of a lower body position relative to the wheel axle, which further improves composure. However, it also makes it harder to lift the front wheel, as the leverage ratio worsens and it becomes more difficult to get past the rear axle’s tipping point.
Contact patch
A longer contact patch improves grip and cornering stability, especially on loose ground or during climbs. The bigger footprint also allows you to run lower tire pressures, as the load is distributed over a wider area. According to the SRAM AXS app, the manufacturer recommends around 10% less air pressure when switching from 27.5″ to 29″ tires, for example. This increases grip even further. Lower pressure also brings another benefit: the tire can conform better to the terrain and effectively “wrap” around obstacles. That improves traction and comfort, but also slightly increases rolling resistance.
Overview: Pros & Cons
| Pros | Cons |
|---|---|
| Rolls over obstacles more easily | Less agile |
| Maintains speed better | Requires more effort to accelerate |
| More traction | Higher overall weight |
| Smoother and more composed ride | Clearance to rider can become an issue |
| Increased comfort |
When things get tight: Why big wheels create a geometry challenge
Riders with shorter legs are all too familiar with the problem: on steep descents, bigger wheels force you to shift your upper body further forward – otherwise, the rear wheel quickly makes contact. The limited clearance can negatively affect balance. Too much weight over the front wheel is far from ideal in steep downhill terrain. Another critical point: frame clearance. Seat tubes shorter than 40 cm are rare, even on 100 mm full-suspension bikes. The reason is clear: when the saddle is at its lowest, there’s hardly any room left between it and the fully compressed rear tire.That’s why we’re seeing more and more specialised solutions – saddles with raised rear sections, cut-outs for the tire, or seat post clamps facing forward. All of these are merely workarounds to gain extra clearance.
In theory, the issue could be mitigated with a steeper seat tube angle. But beyond around 79°, the reach values become extremely long while the effective top tube shortens considerably. The result: a compact seating position with a lot of pressure on the hands – which quickly becomes tiring on long rides.
Front-end height on XC bikes: Why ultra-short head tubes are rare
Head tubes under 90 mm are simply unpopular among frame manufacturers – and for good reason. A short head tube must withstand the same leverage forces as a longer one – but over a much shorter length. As a result, the stresses in the head tube area increase significantly, raising the risk of material failure. That’s something manufacturers want to avoid, making short head tubes an unattractive option.
There’s a practical issue too: a low front end requires steeply angled, specialised stems to maintain sufficient pressure on the front wheel. And these stems ideally only work with a steering limiter. Without it, the stem or shifter is almost guaranteed to slam into the top tube in the event of a crash – a type of damage that’s already fairly common on 29” XC bikes.
Do we need 32″-specific components?
Beyond the obvious new wheels and tires, one key question remains: will other components also need to be adapted for 32″ bikes? In short,partly yes.
Suspension forks
Suspension forks will definitely need to be adapted. The amount of work involved depends on the design – right-side-up or upside-down. Right-side-up forks require a completely new casting for 32″, typically made from magnesium. The tooling for this is extremely expensive. That’s why current prototypes all use upside-down fork designs, which can be modified from existing 29″ forks relatively easily. For early development stages, they are the pragmatic choice.
Chainrings
Adjustments in this area will also be inevitable. The increased moment of inertia of larger wheels calls for smaller chainring sizes. Ironically, 27.5″ and 29″ bikes still often use the same chainrings today – even though bigger rings were common at the start of the 27.5″ era. That kind of standardisation won’t work for 32″ – the step up in wheel size is simply too big. Technically, though, it’s not a problem: small chainrings already exist. The important part is ensuring that rear suspension kinematics are optimised for those smaller rings.
Chainring offset, rear end width & Q factor
In this area, few changes are likely to be needed. A 55 mm chainring offset and 148 mm rear end still provide sufficient space for viable frame geometries. The trend toward ultra-short chainstays is over anyway.
In recent years, the main concern has been wheels becoming overly stiff. At the same time, many bikes still struggle with excessively wide rear ends – evident in the heel rub marks often seen on chainstays. Another factor: XC racers aren’t big fans of wide Q factors, since they rack up a lot of road bike miles where the Q factor is noticeably narrower. While they’re less sensitive to this today than in the past, there’s no reason to make things any wider.
Racing as an innovation driver
What influence does racing have? A huge one! If top riders are faster with new equipment, they’ll demand it. While the pressure in MTB isn’t quite as intense as on the road, the logic remains the same: if a team costs several million euros, €100,000 in development costs can feel like peanuts. And if racers truly go faster with a new setup, there’s a good chance it will make it into production.
Especially in MTB, XC and DH, racers have the greatest leverage. In downhill, there are already rumours about 32/29″ mullet setups. And in cross-country? Things have already progressed further: the first training sessions with 32” wheels took place this year in the Cross-Country World Cup – and it’s quite possible we’ll see them in regular use by 2026. What gets tested in races today could reshape the market tomorrow.
The OEM perspective: Opportunities and risks
The concept makes most sense in the high-end cross-country segment. But even there, it adds about 400 g of extra weight – which may not sound like much, but in this category, it’s a big deal. Especially since we’re talking about rotating mass, which, as mentioned earlier, significantly affects acceleration. If a mid-range 120 mm full-suspension bike priced over €5,000 ends up weighing 13 kg instead of 12 kg, there will be backlash. Even now, many customers are complaining about increasing weights and rising prices. For manufacturers, this presents a dilemma: introducing a new wheel size means low production volumes for tire, fork and wheel manufacturers. That leads to more variants, higher tooling costs, added operational complexity and increased warehousing – in short: it won’t be cheaper or lighter.
Another issue: small to medium frame sizes. Many riders are already struggling with clearance issues. And smaller bikes are underrepresented, even though they serve a much larger target group – like women and younger riders. XXL bikes sell far worse than XS and S frames. On the other hand, the share of riders over 1.90 m tall is also quite small.So, is the effort even worth it?
This development is hitting a market where sales of traditional pedal bikes are steadily declining. Brands with strong racing backgrounds – such as Cannondale and BMC – are under pressure to deliver real innovations. A new wheel size could potentially offer greater benefits than trying to shave off a few more percent in weight.
Our conclusions about 32” wheels
Revolution or just the next market bubble? Have we moved past the mistakes made during the rise of 29” wheels, and have we learned from them? Back then, the 29ers’ breakthrough was held back by a host of technical issues. With 32”, we’re much better prepared. Weight weenies no longer have the final say, and the visual habits of riders have evolved – not least thanks to the plus-size era and the first wave of e-bikes. But are the advantages of 32” enough to spark a new wheel revolution? Probably not.
For shorter riders, 29” is already pushing the limits, and traditional pedal bike sales continue to decline. In the e-bike segment, 32” will likely play no role: the trend here is toward mullet setups (29/27”) due to even more severe clearance issues caused by motors. Add to that the high costs and logistical complexity of small production volumes.
As such, 32” bikes are likely to remain a niche – dominated by brands with a strong racing focus and optimised for tall riders. But only if racers are truly faster on the new format. Until then, one question remains unanswered: innovation or exaggeration?
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Words: Reynaldo Ilagan Photos: Peter Walker, Julian Schwede, Factionbike Studio