What is a mullet bike? Your complete guide to mixed wheel setups
Tempted by a mullet mountain bike? No haircut needed.
Mountain bikers love jargon. Whether you are shifting your mech, pressing your BB or measuring your stack, it is a sport with its own language. Mullet bikes are another example of this, a bad joke based on the famous 1980s haircut. It refers simply to bikes where the front wheel is larger than the rear wheel. Choosing this combination of wheelsizes changes how the bike handles compared a bike with both wheels the same size, and it comes with some advantages and disadvantages. This short guide will help you understand what they are and whether a mullet setup might be right for you.
Contents
What is a mullet bike?
A mullet is any bike where the front wheel is larger than the rear wheel. Generally, it refers to a mountain bike with a 29-inch front wheel and a 27.5-inch rear wheel, but it can apply to any type of bike with this kind of setup. In the past, there were mountain bikes with 26-inch front wheels and 24-inch rear wheels, and maybe one day people will sell bikes with 32-inch front wheels and 29-inch rear wheels.
Why ride mullet mountain bikes
The term ‘mullet’ comes from World Cup downhill racing. In the past, downhill was a 26-inch-wheel-only sport and the idea of a downhill bike with larger wheels was derided for a long time. As the wider mountain bike industry moved to bigger wheels, downhill was slow to follow suit. 27.5-inch wheels were begrudgingly accepted, and the first 29-inch downhill bike appearing at a World Cup race was a noteworthy day in the sport. More than anything, the sport of downhill is based on testing, and in testing, riders began to see that these new, larger-wheeled bikes were faster - and the 29-inch-wheeled bike was the fastest of all. Before long, the whole paddock was running bigger wheels.
They found that 29-inch wheels rolled over obstacles more easily and carried more speed. The problem with larger wheels in downhill was that they made the bike harder to handle for smaller riders and were not quite as quick to change direction. Looking for a way to get the handling of a smaller wheel but keeping the monster truck feeling of a bigger front wheel, they tried 29-inch front wheels and 27.5-inch rear wheels and coined the phrase “mullet” setups.
This combination became the default setup for all of the world’s top downhillers, regardless of height. Racers found that the 29-inch setup was still the ultimate for all-out speed, but the margin for error was too small. Being even slightly off line could mean a significant loss of time. The mullet setups were not much slower, but more importantly, they left room to make mistakes in their race runs without paying a huge penalty, which translated to more consistent race results.
How do mullet wheels work
Mullet setups make your mountain bike easier to handle in technical sections. On the front, 29-inch wheels are great for rolling over obstacles and carrying speed. One downside is that for riders with shorter legs, larger wheels on the rear can make the bike harder to handle. The size of the wheel means it can get in your way when you are off the back of the saddle on descents. If you are over 6 feet (182cm) tall, then this is likely not going to be an issue for you.
There is also a difference in how the bike handles. Comparing tyres and rims with identical construction, a 27.5-inch wheel would be lighter than a 29-inch wheel because the rim and tyre are smaller. This reduced weight makes the wheel slightly easier to turn. Going from a larger to a smaller rear wheel will also change how much traction you get. 29-inch wheels have a larger contact patch, which means more grip. For riders who prioritise climbing, this may be an advantage, but for playful riders, this makes the rear end of the bike harder to move around on the trail.
This combination of lighter weight, less grip and more space for the rider to move around makes mullet setups a favourite for riders who prioritise bike handling over outright rolling speed. The fact that the world’s top downhill racers choose this kind of setup, regardless of how tall they are, shows that these benefits can make a difference for any rider.
What does mullet MTB mean for different riding styles
Whether a mullet is the right setup for you will likely depend on the kind of riding you prefer doing:
Downhill riding
Mullet setups are the preferred wheelsize combination of the world’s top downhill racers. After extensive testing, our factory downhill team agreed, and this is why our Sender downhill bike is mullet-only.
Enduro riding
While enduro is not so different from downhill, by adding in long climbs and stages that may include longer, flatter sections, the priorities change. We made our Strive enduro race bike 29-inch only because our elite racers told us it was faster for them. While a mullet may be faster in the gnarliest downhill sections, over a whole day of racing and riding with varied terrain, they found larger wheels to be faster than a mullet setup.
Trail and all-mountain riding
When you get into trail and all-mountain riding, there is no right or wrong answer, just what you find fun. If you are the kind of rider who prefers to explore and cover distance, you may find a mullet setup a little harder work on the climbs and rolling along. But if you live to search for the biggest grin possible on the way down, then a mullet setup might be just what you are looking for. To allow riders to choose what kind of fun suits them, we made our award-winning Spectral trail bike compatible with both setups, so you don’t need to decide.
Cross-country considerations
When it comes to cross-country riding, the verdict is unanimous: full 29-inch setups are the winners. Head to any cross-country race and you will struggle to find a rider with a mixed wheel setup, because in a sport of small margins, nobody wants to give up rolling speed. When we designed our World Cup-winning race cross-country bike, the Lux, it had to be 29-inch-only.
Converting my bike to a mullet
It is not difficult to convert your current bike to a mullet - all you need is a smaller rear wheel. Because it is smaller than the existing wheel, as long as you have the correct axle spacing, it will fit in your frame. However, it will affect your geometry and suspension:
Geometry changes
A smaller rear wheel will change the geometry of your bike quite a lot, and this is not always a good thing. The first, and most obvious change, is that a smaller rear wheel will lower it your bottom bracket. This will make the bike more stable, but it stops being a good thing if it is so low that you are hitting your pedals as you ride.
Because a smaller rear wheel effectively tilts your frame backwards, it will change the head angle, the seattube angle and the reach. A slacker headangle is considered a benefit by many riders, as it means the steering will be calmer and less likely to be deflected on technical descents. Where the changes are less positive are in the reach and seattube. The seattube angle will become slacker, which will put your pedalling position further behind the bottom bracket, making it less efficient. Shortening the reach means that your riding position will become shorter too, which will change how the bike fits you. If you would like to understand more about mountain bike geometry and how it defines your riding experience, we have produced a short guide to help you understand the basics.
Suspension changes
Suspension setup is all about balance. By shifting the geometry of the bike, you will need to set your suspension fork a little diffetently to get the best performance out of it. With a slacker headangle, you put less weight through the fork, so it will need to be a bit softer to have the same feel. This rearward shift also means you will need to increase pressure in your rear shock as your weight will be further back on the bike. If the new rear wheel is heavier or lighter than your old rear wheel, you may need to either speed up or slow down your rebound to achieve the same feeling you had before.
Is a reverse mullet bike worth trying?
We have yet to meet a rider who thinks this is a good idea. It is certainly possible; any bike could be set up like this, as there is no compatibility issue putting a smaller wheel in your fork. If you did choose to do this, you would find that your front end would be lower, which would lean the bike forward, putting you in a less confidence-inspiring riding position for descending. You could find a longer fork to correct the bar height, but there is no performance benefit that we know of in having a smaller front wheel.
Who should consider a mullet bike: Pros and cons
Sometimes, if you’re stuck trying to make a decision, the only way through is a good, old-fashioned pros and cons list:
Mullet setup
| Pros | Cons |
|---|---|
| Lighter rear wheel is more agile | Reduced traction thanks to smaller footprint |
| Smaller rear wheel is less likely to get in your way | Does not roll as fast |
| Less grip for a more playful ride | More likely to be deflected by obstacles |
| Lighter wheel for better acceleration |
29er setup:
| Pros | Cons |
|---|---|
| Carries speed well | Heavier so harder to get up to speed |
| More traction | Increased weight makes it less agile |
| Rolls over larger obstacles | Larger rear wheel is more likely to get in your way |
| More stable for a calmer ride |
The question comes down to which parts of the ride are most important for you - do you love climbing and covering distance? Or do you want to eke every last drop out of fun from your descents? If you are still not sure which would suit you better, we wrote a more in-depth guide comparing mullet and 29er bikes.
Mullet vs 29er: Sender CFR Underdog vs Spectral CF 7
- Sender CFR Underdog - Canyon Sender CFR Underdog – World Cup speed and control, built tough for privateers.
- Spectral CF 7 - Trail balling on a budget. CF performance, accessible pricing and a solid spec. A lot to love, nothing to hate.
Summary: Is a mullet bike right for you?
We like to say that there is no right or wrong answer for what mountain bike you choose, but that is not quite true in this case. If you are racing, we think there are clear answers for a mullet setup - yes for downhill; no for enduro and cross-country. But when it is just you and your bike out on the trail, there are never right or wrong answers, just what you find fun. Do you prefer outright speed or playfulness?
If you are unsure about what type of mountain bike would suit you, we have created a series of buyers’ guides to walk you through the different styles of riding and the bikes that go with them. If you feel completely at sea, our bike finder tool will take you through a series of simple questions to help you find your perfect partner. And if you get through all that, but cannot make the call between models, our bike comparison tool lets you compare bikes head-to-head.
Just remember that wheelsize is never as important as the smile on your face when you are riding. See you out on the trails!
FAQs about mullet bikes
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About the authorMatt Wragg
Get to know Matt Wragg, the freelance photographer, writer, and self-proclaimed bicycle-breaker based in Nice, France. Despite unsuccessful attempts at XC, trials, 4X, and DH racing, Matt's passion for mountain biking never waned. After a stint in communications consulting, he decided to pursue his love for cycling and moved to New Zealand. Since then, he has traveled the world, chasing trails and building a successful career as a cycling photographer and writer. In 2021, he was diagnosed as autistic and has been coming to terms with it. His bike cellar is a true testament to his love for cycling, housing bikes that range from freeride to cargo.
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