Pinkbike spotted it first: Martin Maes wheeling a one-off aluminum Orbea Rallon DH through the pits at Val di Sole with a 32-inch wheel jammed into the front end and a 27.5-inch wheel out back. Not a typo, not a photoshoot bike. Maes is set to race it at the 2026 UCI Mountain Bike World Championships, running August 26-30 in Val di Sole, Italy — and if he lines up on it for qualifying, he’s the first rider to take a mega-mullet setup into a UCI-sanctioned downhill event.

We’ve spent the back half of this month tracking 32-inch wheels move from XC curiosity to marathon race prototype to production carbon rim. This is the format’s first trip into gravity racing at the highest level it gets, and it’s arriving on a bike that’s been raced approximately ten times, ever, by the person about to send it down the Black Snake.

Quick Take

Rider	Martin Maes, Orbea
Wheels	32in front, 27.5in rear — a “mega mullet”
Frame	One-off aluminum Orbea Rallon DH prototype, not the team’s production carbon bike
Notable features	Bolt-on BB housing for adjustable BB height, slotted downtube built for a bolt-on “Customizable Stiffness Plate”
Fork	Fox 40, modified to clear the 32in front wheel
Tires	Schwalbe Magic Mary, 32in downhill-specific casing
Event	2026 UCI MTB World Championships, Val di Sole, Italy — DH qualifying Aug 28, finals Aug 29
First of its kind	First mega-mullet bike at a UCI-sanctioned downhill race
Best for	Watching, not buying — this is a single prototype with no production plan
Skip if	You want anything resembling a spec sheet you can order from

Wait, What Makes This a “Mega” Mullet?

A regular mullet mountain bike runs 29-inch up front and 27.5-inch out back — Frameworks’ 2026 DH frame does exactly that, and it’s common enough in gravity racing that nobody blinks anymore. The UCI has allowed 29-inch fronts in DH for a while now, and plenty of World Cup bikes run it.

Maes’s bike skips a size class entirely. Instead of 29 front / 27.5 rear, it’s 32 front / 27.5 rear — a three-inch spread between the wheels instead of the usual one and a half. That’s the “mega” part, and it’s not a new idea in gravity racing this year. Neko Mulally won the Sea Otter Classic DH back on April 19 on a 32-inch front / 29-inch rear Frameworks prototype — the first mega-mullet win anywhere. Maes’s spread is bigger still, and Sea Otter isn’t a UCI race. Val di Sole is. That distinction is the entire story here.

The Prototype: What’s Actually Bolted to Maes’s Bike

Per Pinkbike’s pit-lane reporting, this isn’t the production Rallon DH the rest of Orbea’s roster is racing this week. It’s a separate, one-off aluminum frame built specifically for Maes’s experiment, running Orbea’s own in-house OQUO wheels rather than an off-the-shelf set.

Three details stand out:

1. A bolt-on bottom bracket housing. Instead of a fixed BB shell, the housing bolts to the frame, which lets Orbea’s engineers try different BB heights on the same front triangle without cutting a new one for every test.
2. A slotted downtube built for a stiffness plate. The underside of the downtube has a long slit surrounded by mounting bosses, designed to accept a bolt-on brace Orbea calls a Customizable Stiffness Plate. Maes has been riding without it.
3. A mid-race frame revision. During Worlds week, the bike went through a front-triangle swap that removed the downtube slit entirely, paired with a switch to a stiffer carbon seatstay out back. That’s not a small tweak — that’s Orbea deciding, days before racing, that the frame needed to be stiffer than the modular version allowed.

Add it up and you get a picture of a team actively chasing stiffness, not celebrating a finished product. Maes has logged roughly ten laps on the frame total. Orbea kept his regular production Rallon DH in the pits as a backup — which tells you plenty about how settled this decision actually is.

What’s the Downside of a 32-Inch Front Wheel on a DH Bike?

A larger front wheel changes more than rollover. Bigger diameter means more material spinning further from the axle, and on a downhill bike that’s landing drops and slamming into square-edge hits at speed, that tradeoff shows up fast:

1. More flex. A 32-inch wheel and the fork holding it are inherently more flexible than their 29-inch equivalents, which limits how hard a rider can push the front tire into a corner before it washes.
2. More weight to fix it. You can build in stiffness with more material in the rim, spokes, or fork legs, but that adds rotating mass right where you least want it on a bike that needs to change direction fast.
3. No mature tire option. Maxxis’s 32-inch Aspen is an XC race tire, not a downhill casing. Mulally’s Sea Otter win reportedly required borrowing a lightweight tire from another brand that wasn’t built for DH use at all. Schwalbe appears to have solved that specific problem for Maes with a proper 32-inch Magic Mary in downhill casing — a real step forward for the format, even if it’s a one-off tire nobody else can buy yet.
4. No shakedown time. Ten laps is nothing. World Cup DH riders typically spend a season or more dialing suspension and geometry on a new frame before trusting it at race pace on a track like the Black Snake.

Orbea’s answer to the first two problems is the whole reason the Customizable Stiffness Plate and the mid-week carbon seatstay swap exist. They’re not decoration — they’re the frame trying to buy back the stiffness a bigger front wheel costs it.

Val di Sole’s Black Snake Is the Right Track to Ask This Question

Val di Sole’s downhill course, nicknamed the Black Snake, is steep — steep enough that riders typically compensate with a taller front end and more stack just to keep weight off the front wheel on the rollers and steps. Canadian Cycling Magazine’s reporting frames Maes’s bigger front wheel as effectively doing that job mechanically instead of through bike fit — raising the front axle height for control on steep terrain rather than raising the cockpit.

That’s a genuinely interesting way to solve the problem. It’s also exactly the kind of track where a stiffness deficit in the front end gets punished hardest, at the exact moment a rider needs to trust the front tire the most.

This Isn’t Orbea’s First Wheel-Size Swing

Orbea’s broader lineup has already leaned into mixed wheel sizes — the Rallon RS eMTB we reviewed in February runs a 29-inch front and 27.5-inch rear as its default mullet build, and the brand’s engineers told us that setup keeps the back end agile in tight corners without giving up front-wheel rollover. Maes’s DH prototype pushes that same logic three inches further and into a discipline with a lot less room for error. It’s the same company, applying a familiar idea to a much less forgiving test.

What We’re Watching For

Whether he actually races it in finals. Qualifying happens August 28. If the mega-mullet doesn’t feel right, Maes has a conventional Rallon DH sitting in the pits and nobody would blame him for reaching for it.

A result that isolates the variable. Same problem we flagged with Ventum’s Leadville prototype: ten laps on a five-day-old frame makes it nearly impossible to separate “the wheel size” from “the rider hasn’t had time to trust the bike yet.” A strong qualifying run would be a good sign. It wouldn’t be proof.

Whether the tire situation improves. A purpose-built 32-inch downhill casing from Schwalbe, even a one-off, is a bigger deal long-term than anything that happens on race day. Tires are what turned the XC side of this format from a rumor into a shelf item — the Maxxis Aspen 32 did that work for XC racing back in March.

Who Should Care Right Now

32-inch format trackers. This is the format’s first appearance in a UCI-sanctioned gravity discipline, and it’s happening on the sport’s biggest non-World-Cup stage. That’s a real milestone, independent of how Saturday goes.

Anyone curious whether gravity racing follows XC’s wheel-size arc. XC got a rulebook change, a committed tire brand, and four bike manufacturers before anyone raced one competitively. DH is skipping straight to a World Championships start line on a bike with ten laps on it. Different sport, different risk tolerance.

Who Should Wait

Anyone hoping this is buyable soon. It’s a one-off aluminum frame built for one rider’s experiment. Orbea hasn’t said a word about a production 32-inch DH platform, and nothing here suggests that conversation has even started.

Anyone who wants a clean verdict on the wheel size. One rider, one frame, ten laps, one race weekend. That’s a data point, not a trend — the same caveat that applied to Ventum’s 14th-place Leadville debut applies here, and this field is smaller and the track is a lot less forgiving.

The Bottom Line

Martin Maes racing a 32-inch front wheel at a UCI Downhill World Championships is a genuine first, and the frame underneath him — bolt-on BB housing, a stiffness plate built into the downtube, a carbon seatstay swapped in mid-week — tells you exactly what Orbea is worried about. Front-end flex is the format’s known weakness, and this bike is a running argument with that weakness rather than a finished answer to it. Ten laps and a backup bike in the pits isn’t the posture of a team that’s settled anything yet. Whether Maes even starts finals on it Saturday is still the first question. Whether it’s fast is the one after that.

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Reporting sourced from Pinkbike, Canadian Cycling Magazine, BikeRadar, Bikerumor, and the UCI. No test bike has been ridden by our team at time of publication.