Photo by D2 Photographs 

Despite the fact that the more specialist mountain bike wheel sizes have actually been around since the beginning, for many years it was simply all about 26 inches. They were the only mountain bike wheel sizes on offer and nobody questioned it. Today mountain bike companies start exploring the more innovative wheel sizes and unlike the older days, now you can choose between 26″, 29″ or 27.5″ also labelled as 650b.

You also might have heard about 69er specs. It’s not really a novelty, rather an old idea which hasn’t gained much momentum in the mountain biking industry. All thes options can be a little bit overwhelming. The truth is that all of them can have their advantages and disadvantages and many times will mainly depend on your riding style, personal taste and places you are going to ride. Let’s take a look at some pros and cons.



    • Pros: 

      With a current debate in mounting biking being focused mainly between 29″ and 650b (27.5″) wheel sizes, the good old industry standard 26″ wheels are slowly becoming a past. One of the biggest advantages of 26″ wheels is that they are the smallest of the bunch which also means they are lighter. It might not seem much but for serious and competitive mountain bikers, cutting the smallest excess weight and being able to maintain an ability to control the bike is a big deal. Light means better acceleration on exceptionally steep or stepped climbs in rough terrain. 26″ will also add to improved cornering and better “feel”, letting a rider deal with the trail’s obstacles quicker and more effectively.


  • Cons:

    Despite all these great characteristics, handling steep descends at higher speed on a 26” wheel is not for the fainthearted and will require you to have some skills. An extra inch or three offered by 650b and 29ers may not seem to make a difference, but when trying to keep a light and fast moving bike in control, they can be the difference between a fall and a ride in one piece. Also riding position on 26ers has a higher centre of gravity which makes stability even harder to maintain.




    • Pros: 

      650b or 27.5 if you prefer, is the slightly larger wheel that offers a more comfortable riding experience than a 26″ and more stiffness and durability than a 29″ size (the bigger wheels bend more easily). This slightly larger wheel will also make it easier to tackle rough terrain while still being able to accelerate very well. Furthermore, the 650b is a better fit than 29er for individuals of a small body stature.


  • Cons: 

    Slightly larger wheels will mean a bit more weight and angular momentum. This means off-the-line acceleration won’t be the same as in 26er, and the steering will not be as precise and crisp. Even though their top speed will exceed 26″ bikes, it will be slower when compared to 29″.




    • Pros:

      Mr popularity 29-inch size. These wheels are on all manufacturers’ menu. Thanks to their extensive diameter apart from generating the best speed and acceleration at momentum, they make getting over obstacles nothing but easy…well, much easier than 26″ and 27.5″ inch wheels. To quickly make physics easier to understand, a smaller 16 inches tall wheel would hit 8 inches step square on – making the flat front of the wheel contact the top of the step and create a pretty tricky traverse. But if you double the size of the wheel, it will come into contact with the step at an angle, making this obstacle much easier to overcome.


      Another advantage of the larger diameter is a large contact patch with the ground. It will provide much better grip, braking, and generally will be more forgiving than smaller wheels. All these will make the rider more confident in getting through particularly technical and/or steep terrain, especially when descending. It will also make long rides more comfortable and efficient, although geometry of the whole bike will also play the role here.


  • Cons: 

    On the downside, short riders might not feel at home on a 29er. Also, despite being great for acceleration and speed at momentum, getting up to that speed in the first place is a lot harder work making smaller wheel sizes much better here. Handling on technical twisty terrain when turning at speed is required will also suffer when compared to 26 or 27 inches.




Basically, a 69er combines a larger wheel in the front for obstacles, and a smaller wheel in the rear to make up for better acceleration. It’s a good idea in theory, but somehow does not work very well in practicality and usually leaves something missing. Because of a few practical bike-building problems, not many bike manufacturers produce a 69er standalone model. Most of the riders you’ll see on a 69er tend to do so for that sense of individuality that you often find in bikers.



The 29ers become more and more popular and their advantages become a choice not only of the cross country riders but also the downhill specialists. In the style of mountain biking where speed is the main goal, the bigger mountain bike wheel size will carry you much faster. Rolling over obstacles and preserving momentum will also be easier here. But it does not necessarily mean that it is also a better choice for you.

If you are a small rider that can’t fit very well on a 29er, you will probably feel more comfortable going to the next biggest wheel, 650b. For trail riding, it will be all about choosing the size that will match your style of riding. If you want more confidence and you’ll more likely roll over obstacles than jump it, go with the added stability of 29er. If you like more play and fun, go with 650b (27.5″) or 26″. Smaller wheels will be easier to loft in the air and allow you to rapidly change direction. But remember the mountain bike wheel size is only one variable in overall bike package.


Buying Guide – 26″ VS 27.5″ / 650b VS 29er Mountain Bikes

Knowing Your 29ers From Your 69ers, and Much More



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