Built to Find Out: Astral, Sour, Manitou and the Mega Mullet Experiment
32 inches up front. 29 out back. 120 mm of travel. And plenty of unanswered questions. Exactly how we like it.
Words: Joshua Riddle / Photos: Kenny Buchanan
Some bikes are built to answer a market need. Others are built to answer a question.
At MADE 2026, Sour Bicycles brought one of the latter. An eye-searing pink, steel, full-suspension prototype based on the Sour Double Choc, running a 32-inch front wheel, 29-inch rear wheel and 120 mm of travel at both ends.
Sour calls it the Mega Mullet. At the front is something equally experimental: Manitou’s camouflaged prototype 32-inch suspension fork. At the rear, a Manitou Mara Pro Inline completes a suspension package built for a bicycle whose geometry, handling and ultimate purpose are still being discovered. Sour’s description might be the best development brief imaginable:
“32” up front. 29” out back. 120 mm of travel. The rest, we’re still figuring out.”
Curiosity Is a Pretty Good Place to Start
Manitou’s exploration of 32-inch wheels has never been based on the assumption that bigger must automatically be better.
Quite the opposite.
Changing something as fundamental as wheel diameter creates an enormous number of questions. Geometry changes. Loads change. Steering changes. Chassis requirements change. Packaging changes. The relationship between suspension, wheels, frame and rider changes with them.
You can’t properly answer those questions by developing a fork in isolation. You need bikes. You need different interpretations. You need riders. Most importantly, you need partners willing to build something without already knowing what the answer is going to be.
That’s why our ongoing relationship with Sour Bicycles has been so valuable. We’ve already explored the 32-inch concept together through the Pasta Party 32 hardtail. The Mega Mullet takes that experiment somewhere completely different. This time there is rear suspension. And this time only one wheel is enormous.
Quite the opposite.
Changing something as fundamental as wheel diameter creates an enormous number of questions. Geometry changes. Loads change. Steering changes. Chassis requirements change. Packaging changes. The relationship between suspension, wheels, frame and rider changes with them.
You can’t properly answer those questions by developing a fork in isolation. You need bikes. You need different interpretations. You need riders. Most importantly, you need partners willing to build something without already knowing what the answer is going to be.
That’s why our ongoing relationship with Sour Bicycles has been so valuable. We’ve already explored the 32-inch concept together through the Pasta Party 32 hardtail. The Mega Mullet takes that experiment somewhere completely different. This time there is rear suspension. And this time only one wheel is enormous.
32 + 29: Changing the Question
The logic behind the Mega Mullet is fascinating.
A 32-inch front wheel offers potential advantages in rollover and maintaining momentum through rough terrain. But larger wheels also create packaging and handling considerations, particularly when the objective moves away from outright XC efficiency toward something more playful.
So Sour and Astral tried something different. Keep the 32-inch wheel up front. Put a 29-inch wheel behind it. Add 120 mm of carefully controlled suspension at either end and see what happens.
Tester Loren described the result as considerably more playful and easier to get airborne than the five 32-inch hardtails he had previously ridden. After adapting to the bike, he found it stable at speed, capable on steep terrain and surprisingly natural despite the different wheel diameters.
In most situations, he said, he simply forgot they were different sizes. There are still questions. Tight uphill switchbacks exposed some of the differences between the two turning radii, and Loren estimates the concept is perhaps “75% there.” That’s precisely the point. A prototype that tells you everything you already know isn’t much of a prototype.
A 32-inch front wheel offers potential advantages in rollover and maintaining momentum through rough terrain. But larger wheels also create packaging and handling considerations, particularly when the objective moves away from outright XC efficiency toward something more playful.
So Sour and Astral tried something different. Keep the 32-inch wheel up front. Put a 29-inch wheel behind it. Add 120 mm of carefully controlled suspension at either end and see what happens.
Tester Loren described the result as considerably more playful and easier to get airborne than the five 32-inch hardtails he had previously ridden. After adapting to the bike, he found it stable at speed, capable on steep terrain and surprisingly natural despite the different wheel diameters.
In most situations, he said, he simply forgot they were different sizes. There are still questions. Tight uphill switchbacks exposed some of the differences between the two turning radii, and Loren estimates the concept is perhaps “75% there.” That’s precisely the point. A prototype that tells you everything you already know isn’t much of a prototype.
Curiosity Is a Pretty Good Place to Start
Manitou’s exploration of 32-inch wheels has never been based on the assumption that bigger must automatically be better.
Quite the opposite.
Changing something as fundamental as wheel diameter creates an enormous number of questions. Geometry changes. Loads change. Steering changes. Chassis requirements change. Packaging changes. The relationship between suspension, wheels, frame and rider changes with them.
You can’t properly answer those questions by developing a fork in isolation. You need bikes. You need different interpretations. You need riders. Most importantly, you need partners willing to build something without already knowing what the answer is going to be.
That’s why our ongoing relationship with Sour Bicycles has been so valuable. We’ve already explored the 32-inch concept together through the Pasta Party 32 hardtail. The Mega Mullet takes that experiment somewhere completely different. This time there is rear suspension. And this time only one wheel is enormous.
Quite the opposite.
Changing something as fundamental as wheel diameter creates an enormous number of questions. Geometry changes. Loads change. Steering changes. Chassis requirements change. Packaging changes. The relationship between suspension, wheels, frame and rider changes with them.
You can’t properly answer those questions by developing a fork in isolation. You need bikes. You need different interpretations. You need riders. Most importantly, you need partners willing to build something without already knowing what the answer is going to be.
That’s why our ongoing relationship with Sour Bicycles has been so valuable. We’ve already explored the 32-inch concept together through the Pasta Party 32 hardtail. The Mega Mullet takes that experiment somewhere completely different. This time there is rear suspension. And this time only one wheel is enormous.
32 + 29: Changing the Question
The logic behind the Mega Mullet is fascinating.
A 32-inch front wheel offers potential advantages in rollover and maintaining momentum through rough terrain. But larger wheels also create packaging and handling considerations, particularly when the objective moves away from outright XC efficiency toward something more playful.
So Sour and Astral tried something different. Keep the 32-inch wheel up front. Put a 29-inch wheel behind it. Add 120 mm of carefully controlled suspension at either end and see what happens.
Tester Loren described the result as considerably more playful and easier to get airborne than the five 32-inch hardtails he had previously ridden. After adapting to the bike, he found it stable at speed, capable on steep terrain and surprisingly natural despite the different wheel diameters.
In most situations, he said, he simply forgot they were different sizes. There are still questions. Tight uphill switchbacks exposed some of the differences between the two turning radii, and Loren estimates the concept is perhaps “75% there.” That’s precisely the point. A prototype that tells you everything you already know isn’t much of a prototype.
A 32-inch front wheel offers potential advantages in rollover and maintaining momentum through rough terrain. But larger wheels also create packaging and handling considerations, particularly when the objective moves away from outright XC efficiency toward something more playful.
So Sour and Astral tried something different. Keep the 32-inch wheel up front. Put a 29-inch wheel behind it. Add 120 mm of carefully controlled suspension at either end and see what happens.
Tester Loren described the result as considerably more playful and easier to get airborne than the five 32-inch hardtails he had previously ridden. After adapting to the bike, he found it stable at speed, capable on steep terrain and surprisingly natural despite the different wheel diameters.
In most situations, he said, he simply forgot they were different sizes. There are still questions. Tight uphill switchbacks exposed some of the differences between the two turning radii, and Loren estimates the concept is perhaps “75% there.” That’s precisely the point. A prototype that tells you everything you already know isn’t much of a prototype.
120 mm That Feels Like More
There was another piece of Loren’s feedback that caught our attention. On rough, late-season trails, he found that the large front wheel combined with the Manitou suspension seemed to “feel like more than the 120mm of travel that it is over bumps and debris.” That’s an interesting observation because it gets directly to what we’re trying to understand through the 32-inch development program. Travel is only one number. Wheel diameter, spring behavior, damping, chassis stiffness, geometry and tire behavior all contribute to what the rider actually experiences on the trail. Changing the wheel presents an opportunity to reconsider how those ingredients interact rather than simply scaling an existing solution upward. Our prototype 32-inch fork draws on the development knowledge behind platforms including Mattoc and R8, but its purpose is to help us learn what this new wheel size actually requires. The dazzle camouflage may hide the details. The Reverse Arch makes its lineage considerably harder to disguise.
Manitou at Both Ends
Of course, a full-suspension experiment gives us another opportunity that a hardtail cannot. At the rear, a Manitou Mara Pro Inline works with the understroked Double Choc platform to deliver 120 mm of travel and gives the bike a complete Manitou suspension system. Loren’s feedback after riding it was particularly gratifying:
“I also want to say how impressed I am with your suspension. The small bump compliance feels so good.”He ran the suspension relatively soft, finding that it ramped progressively through its travel without problematic bottom-outs. Even after pedaling the bike up a 1,000-meter climb on his first ride, he never felt the need to reach for a switch. That’s the kind of feedback development is ultimately about. Not specifications in isolation. What does the complete bike actually do underneath a rider?
Innovation Isn't New Around Here
The Mega Mullet may look radical, but exploring strange new corners of mountain biking feels surprisingly familiar at Manitou.
We’ve been asking questions about suspension since mountain bike suspension itself was an unconventional idea. As disciplines emerged and evolved, suspension had to evolve with them. XC, downhill, freeride, dirt jump, trail and enduro each created different demands. Wheel diameters changed. Bikes became faster. Riders pushed further. And Manitou repeatedly explored solutions that didn’t necessarily follow the accepted blueprint. Sometimes the result has been immediately visible, like an inverted Dorado or our unmistakable Reverse Arch. Other times, the important differences are hidden inside.
The philosophy remains the same: Physics, not fashion. Thirty-two-inch wheels are simply the latest opportunity to apply it. We’re not interested in deciding that 32 inches is the future and then engineering backward from that conclusion.
We’re interested in finding out what it can do.
We’ve been asking questions about suspension since mountain bike suspension itself was an unconventional idea. As disciplines emerged and evolved, suspension had to evolve with them. XC, downhill, freeride, dirt jump, trail and enduro each created different demands. Wheel diameters changed. Bikes became faster. Riders pushed further. And Manitou repeatedly explored solutions that didn’t necessarily follow the accepted blueprint. Sometimes the result has been immediately visible, like an inverted Dorado or our unmistakable Reverse Arch. Other times, the important differences are hidden inside.
The philosophy remains the same: Physics, not fashion. Thirty-two-inch wheels are simply the latest opportunity to apply it. We’re not interested in deciding that 32 inches is the future and then engineering backward from that conclusion.
We’re interested in finding out what it can do.
Maybe Brilliant. Maybe Nonsense. Build It Anyway.
Sour puts the entire project into perspective rather beautifully:
“Maybe it’s brilliant. Maybe it’s nonsense. Most likely, it’s somewhere in between.”We couldn’t agree more. Because innovation doesn’t begin with certainty. It begins when somebody is curious enough to build the thing, brave enough to ride it and open-minded enough to discover that some of their assumptions might have been wrong. The Mega Mullet already appears to be answering some questions. Loren found the smaller rear wheel helped address some of the packaging compromises he’d experienced aboard full 32-inch bikes on steep terrain and in the air. It wasn’t as outright fast as some of the 32-inch platforms he’d ridden, but he was equally clear that speed wasn’t its only objective. His description was considerably more entertaining: It’s “way better at partying.” For a pink 32/29 steel prototype built by Sour, that sounds about right.
Hard to Hide
Apparently the experiment is attracting attention too. Throughout MADE, Loren says the Mega Mullet continually drew people into the booth. Riders already following the emergence of 32-inch bikes particularly wanted to see the prototype Manitou fork and ask the obvious question: When can I get one? Even on the way to the trailhead after the show, two riders who had seen the bike in MADE coverage reportedly followed Loren’s van into the parking lot just to see it in person. The pink certainly isn’t subtle. Neither is a 32-inch front wheel. And despite our best efforts with the prototype camouflage, neither is that Reverse Arch. For now, though, the fork remains exactly that: a prototype. There are more bikes to build, more configurations to explore, more data to gather and many more miles to ride before we decide where all of this leads. Fortunately, Manitou has never been afraid of the unknown. Neither has Sour. 32 inches up front. 29 out back. 120 mm of Manitou suspension. The rest? We’re still figuring it out.
