Should You get a 29er or a 27.5 Mountain Bike?


Nowadays 29″ mountain bikes are the standard, but in the last couple of years, 27.5″ MTB’s are on the rise. There’s a big difference when it comes to the wheel size of mountain bikes. Which one is right for you depends on a couple of things.

Should you get a 29″ or 27.5″ mountain bike? If you’re a short person a 27.5 will fit you better. If you’re a taller person go for a 29″ mountain bike. Smaller wheels are more maneuverable and accelerate faster, bigger wheels provide more traction and stability.  

There’s way more to it than that, so let’s have a look at what you can expect from these mountain bikes. Tall people can ride 27.5 and short people can ride 29ers.

27.5 vs 29 mtb illustrated

Comparing Wheel Sizes, 29″ vs 27.5″

In general, 27.5-inch mountain bikes accelerate faster, are more maneuverable weigh less and are more suitable for shorter riders. 29ers accelerate a bit slower but are better at maintaining speed, have more traction, weight a bit more and are better for taller riders.

It still comes down to personal preference, if you’re not short and not tall it’s a tough choice. If you’re in-between sizes, pick a smaller size, it’s easier to adjust a bike with a smaller frame than a larger one. The best course of action is to take them for a test ride and find out what feels right.

In a nutshell, this table shows a few of the differences, I’ll go into more detail to explain the pros and cons of each wheel size.

27.5 Inches wheel MTB VS 29 inches
27.5″ Wheel 29″ wheel
Acceleration Faster Slower
Speed Slower Faster (once up to speed)
Traction Good Better
Attack angle Good Better
Weight Lighter Heavier
Maneuverability Better Good
Bike fit Shorter riders Taller riders
Strength Stronger Weaker

There’s more to it than a static comparison table, it depends on the type of rider you are and the terrain you ride. I remember going from a 26″ to a 29er and I really had a tough time adapting. Once I got used to it I loved it but I still wonder if I should have gone with a 27.5″.

Compared to my old bike, the 29er feels less playful but I’m able to ride longer and more comfortable. It’s a trade-off, and not everybody has the budget to ride both of them. I still grab my 26″ from time to time, it’s an oldtimer by not but I can’t say goodbye.

Maneuverability and Responsiveness

A 27.5-inch mountain bike feels more playful, they handle better on narrow and twisty trails compared to a 29er.  They can be compared to the old 26″ but the larger wheelbase handles obstacles more efficiently. If you still ride a 26″ and are on the fence about 29ers, a 27.5  is a good compromise. You still get to enjoy the snappy feel and fast reaction you’re used to.

27.5″ have a tighter radius on turns and are great for riders on aggressive terrain and want agility to better handle, for instance, switchback turns. A 29er feels a bit sluggish when you have to make sharp turns but are great at keeping momentum in shallow turns, feels much more stable.

29ers are better handling objects like rocks and tree roots, the difference is significant (if you’re used to a 26″) and you’ll be surprised the first few times on how they handle on rough terrain. They also have a bit more clearance which makes it less likely to grind rocks or get stuck behind roots. Making a turn while your pedal is down still can cause you to get stuck and launched though.

If your trail is mellow and you don’t have a lot of twisty terrains, a 29er is probably a better choice.

Attack Angle

attack angle 29er vs 27.5 inch mountain bike illustrated
The attack angle has to do with how wheels deal with objects like rocks, bumps, and roots. The angle forms when hitting an object which can be steep or shallow depending on the wheel size. Bigger wheels deal better with objects compared to smaller wheels.

Obviously, a 29er handles better when rolling over objects, but this doesn’t mean 27.5″ can’t keep up.  Smaller wheels benefit more on smoother trails so if you don’t have too many logs, rocks and tree roots blocking your trail you’re fine. They still can deal with objects perfectly fine but you just have to pay a little more attention to your technique.

When riding a 29er you have to worry less about hitting obstacles in a wrong attack angle, depending on the size of the object. They handle objects better than their ‘little’ brother but suspension and technique also play a part.

Weight Difference

There is a difference in weight when looking at stock mountain bikes. Typically 27.5 MTB’s are lighter because the wheels are smaller and require less material. This also makes them stronger compared to their 29″ counterparts.

While many riders are obsessed with making their MTB’s as light as possible, a casual rider won’t really care. Competitive riders are always trying to reduce the weight, even it’s just a few grams. Long distance XC riders also benefit from lighter bikes and you’d think they’d be better of going for smaller wheels.

This doesn’t have to be true. Tubeless tires are a good way to take off some weight. You need ‘tubeless ready’ wheels though, which adds up budget-wise.

You can reduce a lot of weight by getting a carbon from, handlebars and even seat posts and rims are available in carbon. This comes at a price, carbon is an expensive material and takes a lot of energy to manufacture. Setting up your bike with carbon parts is mainly for the hardcore mountain biker and pros who want to get the most out of their bikes, not for casual riders.

Acceleration and Speed

Bigger wheels mean more speed but slower acceleration. A 29er requires you to pedal harder to get up to speed compared to a 27.5, but once up to speed, it takes less effort to maintain velocity. This is useful on longer, mellow trails and allows you to ride further and harder.

27.5 MTB’s takes less effort to accelerate but you need to pedal harder to keep up with a 29er. Once you get too twitchy parts of a trail you have the advantage and you’re able to make up for the lost time.

When it comes to downhill, a 29er will beat a 27.5. Uphill is easier on smaller wheels because of the faster acceleration and maybe the reduced weight. Don’t rule out tire pressure when it comes to speed, less tire pressure means less speed!

Bike Fit

mountain bike fit -clearance and standover height

This is probably the most important part. A mountain bike needs to fit your body type. No matter how good of a deal you can get, if it doesn’t fit properly you’re gonna have a bad time.

In general, 29ers fit taller riders over 6ft better than 27.5″ MTB’s. Like I said, in general. It doesn’t mean that taller people can exclusively ride 29ers, or short people can only ride 27.5 in. mountain bikes. You might have long legs but a shorter reach for example.

Make sure to try before you buy, go to your local bike shop and they will measure your body and (sometimes) weight to see what exactly fits best.

Rider height Suggested Frame Size
Feet/Inches Inches Inches Size
4`10”-5`1” 24-29” < 14″ XS
5`1″-5`5″ 25-30” 15” / 16″ S
5`5″-5`9″ 26-31” 16” / 17″ M
5`9″-6`0″ 27`-32` 17″ / 18″ L
6`0″-6`3″ 28`-33` 18″ / 19″ XL
6`1″-6`6″ 29`-34` 19″ + XXL

Traction (grip)

The surface area of a wheel helps you to maintain your grip on wet and slippery objects, the larger the area the more grip you have. There are other factors that increase or decrease traction. Your weight, technique and the bikes fit and ability to accelerate has a huge impact.

Because 29-inch wheels have a larger contact patch, their surface has a better grip (traction) compared to 27.5″ wheels. 29ers deal better with slippery objects such as roots, especially in wet conditions. They already have a better attack angle and the extra grip helps you to deal even better on rough terrain.

Don’t underestimate 27.5 though, it’s not like they have an inferior grip, you’ll be fine. If you really want that extra traction you can always consider getting a 27.5 Plus.

Strength

27.5 wheels are generally stronger than 29ers, the larger the wheel the weaker it gets. Of course, the quality of the material also has a huge impact on durability and strength. Cheap 27.5 wheels can be trashed just as 29ers. A rider on 27.5 wheels can trash a trail a bit harder compared to a 29er of the same quality and materials.

What About 27.5 Plus?

27.5 27.5 Plus and 29 inch mountain bike wheels differences illustrated

A couple of years ago the 27.5 plus was introduced. It was an answer from the industry to the demand for more traction on the 27.5. The wheel diameter is the same but the difference it the tire which is deeper, wider and has more volume. Because there’s more room for air inside the tire tread, its closer to the size of a 29er.

Problem and debate solved right? Wrong! Any changes often are heavily debated on forums and mountain bike communities and they never seem to agree.

Anyway, the benefits are clear. More traction compared to the normal 27.5″ and great for soft sand, slippery surfaces and muddy conditions. By releasing some of the air and lowering the air pressure the 27.5 Plus deals even better with obstacles and rough terrain. It still has all the properties a normal 27.5 has but with added traction.

So Which is Better, the 29er or the 27.5?

There isn’t a clear winner here, it depends on what you like and what fits best. You can only make a decision once you tried them out yourself, no video or blog post can help you with that. Just make sure you are well informed before you make a purchase. If you come from a BMX background you probably want something more responsive though.

To sum things up here’s where both excel and lack:

A 29er is better at:

  • Great at maintaining momentum and speed, if you want to ride long distances, you should consider a 29er.
  • Better overall stability, better angle of attack to deal with objects and handles turns more precise.
  • The better traction is great in slippery or wet conditions, plows better through soft sand (lower your tire pressure if sand bugging you).
  • Tall people 6ft+, if you’re having a hard time finding the right fit a 29er is the way to go if you’re shorter than 5’ 4” consider a 27.5.

A 29er isn’t great at:

  • Sharp turns, they react slower but feel more stable.
  • Climbing is a bit harder, but you’ll notice it more on short steep hills. It takes more time to get back up to speed.
  • Jumps and last-minute corrections.
  • Take a longer time to come to a full stop, less responsive.

A 27.5 is better at:

  • Last-minute corrections and overall agility. They feel responsive compared to the 29ers.
  • Accelerating and climbing, they require less effort in these types of situations.
  • Jumps and gaps, it just feels more natural.
  • Great for shorter riders who have a hard time finding the right fit.
  • Aggressive gnarly trails, the bike allows for more trashing. Great handling through technical terrain.

A 27.5 isn’t great at:

  • Maintaining speed and long-distance rides. It requires more effort to keep up with your buddies.
  • Harder to go over obstacles, the smaller wheel radius decreases the attack angle.
  • Less traction and grip, the wheels have less surface contact compared to 29ers.

Conclusion

No matter which size you choose, 29 and 27.5 are going to be dominant for a long time.  Still to this day the sizes are heavily debated on forums and sites like Reddit. It even creates division between who is right about which wheel size is better, it’s personal preference and nobody is doing it wrong.

Everyone discussing or claiming facts about the wheel sizes whether it’s a 29ers, a 27.5 or a 27.5+, and all their minor differences seem to forget about one thing. You the rider, that’s the true difference. You practice and get better and deal with the advantages and disadvantages using your skills.

You work around the limitations of your bike by using your skills and brain. Feeling insecure about your wheel size should be the last thing on your mind, to each their own.

Another important fact you should base your decision on is the terrain you ride. Which is the most fun and where do you ride most often should factor in your decision which bike you are going for. If you only ride occasionally you probably want something that doesn’t make your ride frustrating.

Climbing can be a pain, as a casual rider you probably want to make this as easy as possible, so pick a bike that can get you through. You need something that helps you deal with the most challenging parts and feels comfortable.

In the end, many bikes can be adjusted to your liking by replacing and upgrading parts. Good luck in finding the right bike for you and be safe!

Related Questions

can you fit 27.5 wheels on a 29er? Not always, it depends on your bikes’ geometry.  you need a 27.5+ tire and a fitting rim that fits. Go to your local bike shop to see if they can help you out.

Can I use both 29/27.5+ wheels in the Same 29er Fork? Most 29er forks won’t fit a 27.5+ tire because they aren’t wide enough. It’s possible when you use a 27.5 Plus fork and then swap between 29 and 27+ wheels. Again, speak to a mechanic at your local bike shop and see what options you have.

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Ruben

I always had a thing for bike sports and love almost anything that involves bikes and boards. I work part-time as a designer in the tech industry and work on my blogs whenever I can.

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