A mountain biker is suspended in mid-air on his bike, with his phone being securely held in place with a ROKFORM mount

How to Choose a Mountain Bike Wheel Size

Mountain biking is a sport that can provide so many different experiences- whether you’re chasing the thrill of a steep downhill ride or the challenge of a technical trail, there’s so many different ways you can enjoy your bike in the great outdoors. There’s many considerations that go into a mountain bike’s design, but one of the primary factors in how your bike is going to ride is the size of the wheel. 

Your bike’s stability, handling, and riding position are all influenced by the wheel size, and smaller or bigger wheels are preferable for different needs. Most mountain bikes are only designed to accommodate one wheel size, it’s worth looking into the pros and cons of different wheel sizes if you have a bike with an adjustable wheel size, or if you’re in the market for a new ride. As the Spring biking season approaches, it’s important to evaluate your gear before you set off on your next big biking trip!

A mountain biker rides on a cliff-side trail, with mountains and scrubby vegetation in the background.

Here at ROKFORM, we know how every part of your bike needs to be top-quality if you’re going to shred some trail. Our V4 Pro Series and Sport Series Bike Phone Mounts will perfectly complement your top-tier kit by providing at-a-glance information about your ride and easy route tracking. Paired with the unbeatable protection of our Rugged iPhone Cases, you can tackle sharp turns and steep drops, fully confident that your phone is safe.

A set of bike handlebars with a ROKFORM  V4 Pro Series Phone Mount on the handlebar stem, with an off-road trail in the background.

Common Mountain Bike Wheel Sizes

Over the years since mountain biking has become a mainstream sport, the industry has settled on a few different wheel sizes as standard for hitting the trail. Below we’ve listed the pros and cons of each wheel size for you to see which one will work best for your needs.

26-Inch Wheels

The 26-inch wheel was the original choice for the development of mountain bikes, and for good reason- 26ers are zippy and easier to haul to the mountains!


  • Nimble and light ride feel 

  • Accelerates more quickly to help you get up to speed after an uphill or sudden stop

  • Smaller size accommodates tighter trails more easily


  • Smaller wheelbase gives you less stability on downhills and makes you lean forward more on uphills

  • Less momentum from a lower mass means that you have to pedal more actively to clear obstacles like roots or holes

The 26 inch wheel has fallen out of fashion in recent years, mainly due to the modification of standard mountain bike geometry to accommodate better suspension setups. Although there are still 26-inch wheel models out there, they generally don’t have much support from manufacturers, and finding replacement parts can be difficult. Still, if you’re looking to feel light on your bike and want the rewards of digging deep to clear a difficult trail, it’s worth trying out some smaller wheels.

A mountain biker, turning sharply on a narrow strip of trail by leaning his weight off of his bike.

29-Inch Wheels

The smaller diameter 26-inch wheel enjoyed a position as the “standard” mountain bike wheel size for the majority of mountain biking’s early development, but larger wheel sizes have caught on for downhill bikes and enduro bikes. 


  • The longer wheelbase of a 29-inch wheel creates a lower center of gravity as you ride, contributing to a more stable feeling as you ride

  • The larger wheels are better at clearing obstacles and retaining grip on the trail due to the tire's larger contact patch with the ground 

  • The larger mass of the tires means that they can use their increased momentum to roll through rough terrain that smaller wheels struggle with, and maintain higher speeds more easily. 


  • 29-inch wheels are more difficult to accelerate, and have a tougher time getting back up to speed after a stop. 

  • It’s harder to maneuver through tight sections of trail as easily as a smaller wheel would, as the increased surface area of the tire on the ground makes it harder to pivot quickly on your wheel.

It’s an incredible feeling to race downhill on a 29er at top speeds, but what’s going to happen when your phone falls off your bike or out of your pocket? You need a case and mount setup that will give you the confidence to shred the trail while following your route and keeping your phone safe. 

Our bike phone mounts are over-engineered to make sure your phone stays on and safe, no matter how badly you take a spill as you’re biking. Our V4 Pro Series Bike Phone Mount is threaded directly into your handlebar stem and features a dual retention locking system, meaning your phone isn’t going anywhere.

27.5-Inch Wheels

A newer addition to the mountain biking world, 27.5-inch wheels promise the compromise that bikers have been looking for since the debate over mountain bike wheel size began. 


  • More stable than a 26-inch wheel and more agile than a 29-inch wheel

  • Allows for a wide wheelbase and clearance for increased suspension compared to a 26er

  • Still tackles quick turns and accelerates without too much effort


  • The 27.5 inch tire is a compromise pick- you won’t get quite as much handling and efficiency as a 26-inch wheel, or quite as much stability and momentum as a 29-inch wheel. 

Especially for new riders, the 27.5-inch wheel is a perfectly acceptable balance of the two wheel sizes. If you don’t have a strong preference after riding multiple models, you’re probably best off going for the all-round pick.

A mountain biker hits a downhill section of trail, leaning forward while standing on his pedals.

Mullet Bikes

Mullet bikes, mountain bikes with a 29-inch front wheel and a 27.5-inch rear wheel, are definitely one of the latest trends in mountain biking, and all signs point to their emergence as a defined niche in the mountain biking community.


  • Offers riders better turning due to the front tire’s increased surface area contacting the ground

  • Rides more gently because of the increased absorption of a larger wheel. 

  • Increased distance from the back wheel helps take the edge off of drops and bumps


  • Mullet bikes are still a new technology, and may lose support over time

  • Running different wheel size changes the weight distribution on your bike, and may feel less stable than an equally sized set of wheels

Mullet bikes are an exciting new development in mountain biking, and you should definitely try one out. It speaks to the sophistication that manufacturers have achieved in bike design that the mullet bike can retain all of the pros of a 29-inch wheel, while minimizing the weaknesses of the large tire with a 27.5-inch rear wheel. But when you set out for a ride, how sophisticated is your phone case?

ROKFORM’s Rugged iPhone Cases offers the durable protection against drops and impacts that you need when you’re riding at your hardest. With seamless integration between our Rugged Cases and our Sport Series Bike Phone Mount, you can attach your phone to your bike in seconds and ride out with confidence that your phone is secured.

Infographic showing the 5 important bike geometry measurements that impact your mountain bike

Which Mountain Bike Wheel Size is Best for Me?

In the end, the best wheel size for you is going to be the one that works the best for the type of riding you do! The easiest way to find your personal preference is to get on some bikes and experience the differences for yourself. If you have friends who ride, try out their bikes and see if you can notice anything you’ve read. If you don’t, your local bike shop will be happy to let you test ride multiple models, and may even offer daily rentals to take it to the trail. 

Ultimately, different options will be the best choice for different mountain bikers, but everyone needs a phone mount they can trust. Easily stick to your route and control your playlist without stopping the fun using our Mountable Phone Cases. Using the tested and proven MagSafe® technology, our iPhone and Galaxy bike mounts lock your phone in place and keep you in the know. If you’re pushing yourself out on the trail, you’ll love the rock-solid protection of the dual-retention mount on the V4 Pro Series Bike Phone Mount.

Table comparing mountain bike wheel sizes

Frequently Asked Questions

How Can I Tell What Wheel Size My Bike/Frame is Compatible With?

Generally speaking, bikes are only compatible with one wheel size. Unless you have a newer mountain bike frame that has a flip-chip, your only way to change your wheel size is to get a new bike. 

If you have a complete bike, you can look at your tire to see what diameter your wheel is. There will be two numbers denoting the size that usually look like “29 X 2.5”. The “29” refers to the diameter of the tire, which is almost always the same as the diameter of the wheel, while the “2.5” refers to the tire width. If you need some help, you can take it to your local bike shop.

If you have a frame, You can generally look at the frame manufacturer’s website to see what wheel type you can use, and whether it has the capability to switch wheel sizes. As you’re building up your bike, make sure you know all the ins and outs of assembling a bike!

How Can I Try Different Sized Mountain Bike Wheels?

While it’s difficult to try a different mountain bike wheel size wheel on your bike without a flip-chip, you can easily find some other bikes to try and get a feel for what wheel size works best for your riding style. Talk to your riding buddies and see if they have a setup that you’re interested in trying. Next time you hit the trail, trade bikes and see how different it feels to run a smaller or larger wheel. That may be all the encouragement you need to get a new bike!

If your friends can’t help you, you can try a private bike rental through sites like Spinlister, who provide daily rentals on some of the best bikes out there. If there’s no one in your area offering the bike you’re looking to try, you can always contact your local bike shop and go for a test ride. Many shops offer daily rentals as well, which gives you the chance to try it out on the trail! No matter what bike you end up going with, our Bike Phone Mounts are compatible with most handlebar sizes, so you’ll still have the ultimate protection!

How Are Technical Skills Like Manuals and Cornering Affected by My Wheel size?

A smaller wheel size will help you manage your balance on your bike for skills like Manuals, since you won’t have to put so much force into getting up and over your back wheel. 26 inch wheels do need finer handling to corner effectively though, as they don’t have as much surface area contacting the trail as they slip into the turn.

Big wheels like a 29er will be harder to get off the ground due to its longer wheelbase, and you may have to use more force to get the bike where you want it for the best balance. On the other hand, your tire will be contacting the ground with a much larger surface area, making tight turns a breeze.

ROKFORM mounts make sure that your phone stays put, even while you’re balancing on your rear end. If you’re looking to practice your tricks, you need to keep your phone from falling out of your pocket. With our Bike Mounts, you’ll always know your phone is staying with you.

A mountain Biker suspends  himself on only his rear wheel with his phone mounted on his ROKFORM bike mount

It’s Time to Hit the Trail!

Whatever bike you end up hitting the trail on, you’ll need a quick and easy way to stick to your route and keep your phone close during every twist and turn on your ride. ROKFORM’S V4 Pro Series Phone Bike Mount will give you the confidence to go all-out on the trail without worrying about your phone’s safety. 

With adjustable straps to accommodate any handlebar and cases for every phone type, the V4 Pro Series mount will keep your phone secure using its powerful twist-lock and magnetic mounts. Whether you’re a seasoned mountain biker or a daily bike commuter, the V4 Pro Series mount will be the last phone mount you’ll ever need for your bike.

A Specialized S-Works mountain bike with a ROKFORM bike phone mount that holds an iPhone.

“Although it's very easy to take it off the stem to swap to another bike, I bought a second. I should have bought these things years ago.” - Ray S

Interested in seeing the V4 Pro Series mount in action? Check out our real-world test run with world-class mountain biker Dave Cullinan!

Dave Cullinan gives his candid thoughts on the V4 Pro Series Bike Phone Mount after putting it to the test on the trail.

ROKFORM: Proven Phone Protection for Mountain Biking

Over 15,000 5-star reviews make it clear that ROKFORM’s phone cases and mounts are built to protect and built to last. Take the perfect picture in seconds and never lose your route again, without having to stop to pull out your phone. Trust a ROKFORM case and mounting system, and you can ensure complete security for your phone while keeping it at a moment’s reach.

Have questions about our products or which case is right for your smartphone? We are available for online chat or in-person at our Irvine, California showroom. Call us toll-free at 855-765-3676, or email us at info@rokform.com, or visit us at www.rokform.com

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