Mountain Bike Wheel Sizes

Wheel sizes on mountain bike

The wheel size on your mountain bike impacts more than you know.

You have three main sizes, each of which have different implications on the total bicycle frame weight, as well as the rider’s height and the overall user experience.

The problem is, no two people experience mountain biking the same. My experience is going to be different from yours, but that makes it hard to definitively tell someone which tire size is better, doesn’t it?

We’re just going to explain the differences to you, and let you make your own decision. Let’s take a look.

Why Do Mountain Bikes Have Different Wheel Sizes?

Different wheel sizes work for different riders because of height and weight differences.

You can be short and build like a Mack truck, or tall and rather slender with room for muscle growth, and you will pedal differently than the person sitting next to you.

This mountain bike wheel size chart goes over the three most common mountain bike wheel sizes, what these sizes have to offer, and the key differences between them.

Standard Mountain Bike Wheel Sizes

wheel sizes

There are three basic mountain wheel bike sizes that you need to look out for.

The whole point of sticking to these sizes is so that you can get tons of traction on the surface you’re riding on, whereas smaller street bicycle tires have a less rough ride ahead. Bigger tires and thicker treads help you quite literally get over whatever is in your path.

29” Wheels

They’re the biggest tires for mountain bikes, and they take a lot of power and force to get ready. The thing is, once you get that momentum going, you can just keep gliding with minimal input from that point on. Once you get it going, it keeps going.

But bigger tires do have issues. While they’re the best for mountain biking because of the insane traction and ability you have to go over large obstacles, that doesn’t change the fact that they include their difficulties.

If you go from a street bike or BMX to 29” tires, you’re going to have quite the time. It’s all trial and error and getting used to it, and your leg muscles will be sore for the first few weeks, but you’ll come along in no time. Even an upgrade from a 26” mountain bike to a 29” is a big step, though admittedly you will know what you’re getting into with it from experience a bit better.

27.5” Wheels

27.5” bikes are usually associated with trail bikes. They’re not downhill bikes, they’re designed for better overall rides by letting you kick off with a good deal of momentum and power right from the get go.

However, these wheel sizes aren’t exclusive to trail bikes. As we’ll mention later, it’s about matching the size of the person that the bikes are designed for, so you could see these on custom or specific downhill bikes, for example.

26” Wheels

These bikes are generally the smallest you see with adult sizes, although some companies go as low as 24” depending on what you want to get. 26” wheels give you an excellent power output to distance ratio, so you aren’t exhausting yourself entirely just by using one of these.

With a 26” bicycle, the frame is obviously going to be smaller as well, which can save you a few dollars here and there. A smaller frame usually means less materials, which saves you money, but 26” wheels also usually have slightly more narrow tires. Let’s talk about that.

Tire Width Matters As Well

tire width

While we’re on the subject of tire sizes, let’s talk about width.

The average width of 26” tires is around 2.1”, but when you get into 27.5” and 29”, that can raise to 2.5” up to 3.1” depending on the manufacturer and the features that they’re trying to push on the consumer.

Is this a good thing? It could mean more air in the tire, more tire pressure, and of course it means a wider contact surface for your bike. Yes, width matters, because a wider tider will allow for better balancing and traction with the rugged terrain you’re about to face.

But it also attributes to less maneuverability. Your dexterity on a bike will feel entirely different with even one full inch of tire width difference. If you’re swapping tires, be very cautious of the width and how it compares to your current tires.

You may be trading handling and movement capabilities for sturdy traction, but that depends on what you need in a mountain bike, and how you like to ride.

While some of us don’t really care about tire weight, it does impact performance. Wider tires will use thicker rubber, or at least more of it, so you will increase your overall bicycle weight.

On top of that, wider tires that use more material will also be more expensive. The cost difference varies, but since mountain bike tires can be on the more expensive side anyway, this shouldn’t really be too much of a shocker.

It’s About Pedal Power

pedal power vs wheels sizes

Bigger tires need more pedal power to get going, and without providing that power, they’re basically useless.

Bigger tires are only as good as the power source that makes them go.

Pedal power can be achieved with smaller tires, you’re just going to have to apply more power immediately upon passing over an obstacle, or rather to be able to pass over an obstacle in the first place.

If you’re unable to mount an obstacle that a 29” tire user can, it’s not just because of the tires. It helps, but it’s not the entire deal. Once you begin your ascent over an obstacle, your momentum immediately declines, and it exponentially declines until you reach the apex of that obstacle.

Having enough pedal power can push you through, and even if it expunges more energy than a 29” mountain bike user, you also have to remember that you may have better handling at the same time, which is what makes those jumps and clearing obstacles possible.

Don’t Forget About Total Energy Output

downhill ride

Bigger tires, more pedal power. We get that.

But that translates to having the right level of energy, and if you don’t have the power to actually truck along, you’re going to run into some problems.

You have to start small. If you were averaging three miles per day on your 26” mountain bike, just know that holding that same stride is going to be a bit tough. Maybe you can do it, but it’s also likely that you will run into some physical walls around the two-mile mark.

Adjusting to larger tires takes more physical energy and tests your endurance. That’s okay. Don’t push your body for the sake of pride, because you just upped your difficulty; give yourself the necessary (short) time that it takes to get used to it, and call it quits a little bit early if you have to.

Fatigue isn’t worth it, because it’s going to mess up tomorrow’s ride even if you go back to those 26ers. Pace yourself and let your body get used to it. Of course, you read this like a cautionary tale, and when you hit the 29ers you might not even struggle at all.

Maybe you’re putting out too much power on 26ers and this is the change you need. You won’t know until you swap out your tires, but just be aware of the energy output before doing it.

Your Bicycle Should Fit Your Body Size and Height

size fit

A super short person shouldn’t be rocking 29ers on a mountain bike.

Yes, they have undeniable perks, but bikes are supposed to fit body sizes. So if you can find a bike frame that fits your body size, short or super tall, that can still accommodate those larger tires, then go for it.

Larger tires are good, but they’re not everything. You want to make sure you’re outputting as much power as you possibly can, not how much some guide says that you should be.

If that means having a smaller bike frame with 26ers instead, then that’s what it means. You may make up in speed what you lack in power, and shred the dirt trails anyway.

Designed With You in Mind

The weight of your bike frame is at stake here, but depending on your height and the power you want for your mountain bike, you may have to go on the higher side of the spectrum.

It’s insane to think about how much the wheel diameter size impacts your overall performance on the bike, but it’s definitely something to think about.

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