Guide to Mountain Bike Wheel Sizes

A Brief History of Mountain Bike Wheel Sizes

For much of the mountain bike’s history, the only available wheel size, or at least the most popular one by a long shot, was 26 inches. However, this all changed in the late ‘90s and during the 2000s when other wheel sizes hit the market and started to gain popularity.

Today, you can choose from a few different wheel sizes, but we will focus on the three most common and popular ones – 26’’, 27.5’’, and 29’’. We’ll also briefly cover plus sizes, which are wider versions of the main wheel sizes for mountain bikes.

26-Inch Wheels – The Long-Lasting Standard

As we mentioned already, 26 inches was the only size of wheels for mountain bikes for a long time. They are still one of the most popular options today, for many reasons.

Advantages of 26-Inch Wheels

First of all, 26-inch wheels are very nimble, which makes them good for twisty tracks and generally easier to control on trails, including having better cornering mechanics. Another advantage is the rate of acceleration that this size has on smooth surfaces, which is much faster compared to other wheel sizes.

Since 26’’ wheels have been around for a long time, there is an abundance of components and spare parts to be found. This may not be the case with other wheel sizes, so getting your wheel repaired is usually much easier and faster if you have a 26-inch wheel. Also, both repairing and upgrading 26-inch wheels is cheaper due to the number of available components.

Of course, 26-inch wheels are also lighter and more responsive than other sizes. This is the smallest and lightest mountain bike wheel size, which also makes it the strongest since bike wheels are only as strong as the tension of their spokes. So, longer spokes mean less tension and strength.

Disadvantages of 26-Inch Wheels

The main disadvantages of smaller wheel sizes are grip and rolling resistance.

26-inch wheels have a smaller contact patch than larger wheels, which can be noticed when you try to brake. To put it simply, 26’’ wheels don’t have as good traction as bigger wheels.

The rollover ability is the other problem of smaller wheels since they have a higher rolling resistance. Their size means that you’ll hit things at a steeper angle, plus they drop into holes easier. You may also notice that they lose speed faster than bigger wheels.

27.5-Inch Wheels – Best of Both Worlds

27.5’’ wheels, or 650B as they are also called, are the medium size of mountain bike wheels, so they offer a balanced solution that combines features from 26-inch and 29-inch wheels.

These wheels are the newest option on the market since they’ve only appeared in 2012, but they’ve been gaining popularity in recent years.

Advantages of 27.5-Inch Wheels

As expected, 650B wheels present the middle ground between 26ers and 29ers. To put it in perspective, they are between the other two sizes in terms of acceleration rate, traction, rollover ability, weight, strength, maneuverability, etc.

They are a good choice for people who find 29-inch wheels too heavy and don’t like how they fit. Compared to them, 27.5’’ wheels offer a more natural wheel placement and better handling, while still retaining some of the advantages of the bigger wheels.

Likewise, they provide better traction for those who find 26-inch wheels unreliable on slippery rocks and similar trails. They simply offer a smoother roll without sacrificing as much as 29-inch wheels in terms of maneuverability and control.

Disadvantages of 27.5-Inch Wheels

Since 650B wheels are the most balanced option, they don’t have any big disadvantages when compared to the other two options. That being said, whether this balance suits you or not is completely up to you. Some people like it, while others like the benefits of smaller or larger wheel sizes despite the disadvantages.

Additionally, 27.5in wheels are still relatively new, so they can be difficult to fit with existing bike frames and other components. Of course, that is changing rapidly and the options are more abundant with each passing day, but they are still behind 29in wheels, and especially 26in wheels. That also means that they are the more expensive option than the other two, all things considered.

29-Inch Wheels – Size Matters

The biggest wheel size for mountain bikes is 29 inches, which comes with a unique set of benefits and a few drawbacks. So, they’ve been causing a bit of a stir since they first appeared on the market in the 2000s.

These wheels were mostly used on cross-country bikes in the beginning, particularly hard-tail models. They are still the most popular option for XC bikes, but many riders use them on downhill bikes today as well, even by professional racers.

Advantages of 29-Inch Wheels

The main benefit of 29in wheels is their ability to easily roll over obstacles on the trail. Their size gives them a shallower attack angle compared to smaller wheels, which means that they hit the objects at a lower point and roll over them with less resistance. This, in turn, provides a smoother ride on bumpy trails and even allows you to ride terrains that may be inaccessible otherwise.

Another advantage of 29-inch wheels is the ability to maintain speeds more efficiently than smaller sizes. While they have a lower acceleration rate, once you reach a certain cruising speed they will be better at keeping the momentum.

Disadvantages of 29-Inch Wheels

Bigger wheels aren’t for you if you are primarily concerned with control and responsive handling, since smaller wheel sizes provide better control and maneuverability. We’ve already mentioned acceleration rate, which is another drawback of 29in wheels.

Of course, these wheels are also the heaviest option and not the strongest since they have longer spokes. Some people may also be put off by their appearance since they often make the bike look awkward and out of proportion.

Plus Wheel Sizes for Mountain Bikes – What Are They?

All wheel sizes for mountain bikes are available in the plus-size version, although the most common type is the 27.5+ wheel size. In any case, the main difference between standard and plus wheel sizes is the width. That means that the standard and plus sizes have the same internal diameter, but plus sizes are wider than standard sizes.

The main advantage of plus sizes is the increased grip they provide since they have a larger contact patch than standard sizes. They offer better traction without losing much in terms of rolling resistance. These wheels are also good if you are looking for added stability for confidence.

On the downside, plus-size wheels are heavier, which also means that they are less nimble. So, you won’t have the same handling and control as you have on standard sizes. Additionally, they are more expensive than standard wheel sizes.

All in all, plus wheel sizes are useful and worth considering if you are riding on loose terrain. However, if you mostly ride on smooth terrain and don’t need any added stability, plus wheel sizes may not be worth the trouble.

Factors to Consider when Choosing the Mountain Bike Wheel Size

When you think of the best mountain bike wheel size, the truth is that all of them have certain advantages and disadvantages. So, the right wheel size for you depends on a few different factors and your unique needs.

Your Experience Level

If you are new to mountain bikes in general, the first thing to do is find the best mountain bike for beginners. This will directly impact your choice of wheels because not all bikes can support all wheel sizes without serious modifications.

And while beginners can do just fine with any wheel size, perhaps the best option for new riders are 27.5-inch wheels. These wheels are balanced and won’t have serious drawbacks like smaller or bigger wheels. Once you get used to mountain bikes and you develop a feel for riding and different types of terrains, you might make a change to 26in or 29in wheels to suit your riding style and needs.

Your Height

Perhaps the most important factor to consider is your height. First of all, it is important to note that bike frames are engineered around the wheels, so bikes with bigger wheels also have to be bigger, with longer wheelbases, chainstays, etc. So, if you are not height enough, choosing the 29-inch wheel size will most likely feel too big.

In general, 29’’ wheels are suitable for people who are 5’7’’ or taller, while riders who are smaller than that usually find that 650B or 26-inch wheels suit them better and feel more natural on rides.

Type of Terrain and Ride

As we mentioned before, bigger mountain bike wheels are better if you are mostly riding uphill, as well as for riding over rough terrain in a straight line. If you are looking for a smooth ride on rough terrain, 29in wheels are the best option due to their good rollover ability.

Meanwhile, smaller size wheels are better for riding downhill since they are more nimble and offer more suspension travel. If you are looking for a better handle and more control, 26in wheels should be your choice.

Conclusion

Wheel sizes for mountain bikes come in a few different options, and each of them has certain benefits and drawbacks. Choosing the right wheel size is ultimately down to your personal preferences and needs.

Hopefully, our article provided you with some insight into mountain bike wheel sizes that will make your decision a bit easier.