29 vs. 27.5 Mountain Bike Wheels: How to Choose
Navigating your way through the world of Mountain bikes is more challenging than ever, thanks to so many options. The first one you are going to come across is whether to go with 27.5 or 29-inch wheels. There are a few factors to consider when deciding what will suit you. Riding style, riding goals, terrain and comfort all come into play when determining what is for you. Let's dive in deeper to find what is suitable for your riding.
29 inch
Fast and Smooth
Pros Cons
Grip
29-inch wheels have been around for many years now. Thanks to their increased rollover, enhanced efficiency and stability at speed, they have been a staple in XC racing for over a decade. In the last few years, they have been sneaking onto Trail, Enduro and Downhill bikes thanks to a giant leap forward in bike geometry.
Racing is where the 29-inch wheel shines. Thanks to a shallower attack angle, 29-inch wheels roll over obstacles with ease. The greater rollover allows riders to hold their line easier, not worry about getting bucked around and hit obstacles faster, thanks to the 29-inch capabilities. The bigger wheel diameter also provides a greater contact patch on the ground, leading to more traction over all terrains.
Confidence can be found when rolling on 29ers. 29ers have more weight further away from the hub that keeps them rolling for longer. Extra weight partnered with the greater rollover allows riders to cruise along without worrying about getting thrown over the bars on a rough trail. As you go faster, the wheels become more stable, giving a rider more confidence at speed.
Conventionally, the downsides to the extra weight and rollover are apparent in two riding avenues, agility and playfulness. Unfortunately, the extra stability and weight lead to a bike that requires more effort to change direction. A bigger diameter wheel also has a bigger turning circle, making it more difficult to navigate a tight single track without excess body language. However, thanks to modern Geometry, these cons are less apparent on modern trail bikes.
Shorter riders with shorter legs may have issues with 29er wheels as the wheel may hit them while riding over the back wheel. While uncommon, it is worth considering smaller wheels as a 27.5 may suit shorter riders better.
27.5 inch
Fun and Play full
Pros Cons
Grip
27.5 have been around for many years as a slight step up from the traditional 26-inch wheels of the past. 26 inch wheels were too small, 29ers were too big, so 27.5 was the goldilocks in between sizes. They provide a greater rollover and stability while retaining the agility of a smaller 26-inch wheel. It is the most versatile wheel size and suits most riding styles except XC, where you want the efficiency of a 29er.
The smaller wheels are lighter, have a smaller turning circle, and because of these characteristics, they are more agile. Mountain bikes rolling on 27.5-inch wheels turn with ease and love to dart through tight technical singletrack. Along with changing direction quickly, 27.5 wheels accelerate quickly and get up to speed in no time.
While the decreased rollover leads to some negatives like getting thrown offline easily and slower through the rough trails, they love to jump and be active over the travel. Smaller wheels are easier to pick up when you need to lift a wheel; keeping the bike light and jumping over obstacles is where 27.5-inch wheels shine.
There are some downsides to the smaller wheels, though; they tend to get hung up in rougher terrain and are less stable at speed. While the playful nature is great at slower speeds, the bikes can become unstable once things get fast and require more courage from riders to go as fast as possible. If you want a more stable wheel at speeds and irons out the rough stuff, then 29ers are for you.
The Basketball (29er) Vs The Golf Ball (27.5)
As a bonus, we have a small analogy to give readers a better visual of how each wheel behaves. Imagine you are standing at the top of a hill on a cobbled road. You have a Basketball and a Golf Ball. You get both of them in your hands and roll them down the road. The Basketball will pick up speed slowly, travelling straight without any deflection by the bumps in the road. The golf ball will start fast, but it will change direction spontaneously and deflect all over the place. The Basketball will stay grounded and maintain contact while the golf ball is getting thrown up in the air and bouncing around down the hill. This scenario is a good visual representation of how a 29er (Basketball) handles trails compared to a 27.5 (golf ball).
Each wheel has different pros and cons that suit different riding styles. We will have articles on different mountain bike styles in the future but, for now, enjoy the ride.