How to Choose a Mountain Bike

Often described as “skiing in the summer”, mountain biking is a sport that is exponentially growing in popularity – and for good reason. It’s a way to scratch that adrenaline itch during the warm weather months, an excuse to be outside all day, and a great way to make new friends!

But as the bike industry grows, so does the number and types of bikes to choose from. How do you know which bike is best for you?

Read on to learn how to navigate the various types of bikes, what makes them different, and other features you’ll want to know about.

Now let’s kick it into high gear, shall we? (Pun very much intended).

BIKE GEOMETRY

There are various types of mountain bikes to choose from, which we will get into soon. But first, it’s important to know what bike geometry is and the associated terms.

  • Head Tube Angle: The angle between your fork and the ground. Steep head tube angles will make your bike feel more responsive and ‘twitchy’, which is great for cornering on flat terrain. Slack head tube angles will make the bike feel more stable on descents, though not as snappy in corners.
  • Seat Tube Angle: The angle between your seat tube and the ground. Seat tube angles have been getting steeper throughout the years to put the saddle directly over the bottom bracket. The steeper the angle, the more efficient and easier pedaling will be.
  • Chainstay Length: Distance between the center of the rear wheel (rear axle) and the center of the bottom bracket (center of the cranks). Shorter chainstays will make it easier for you to lift the front wheel (think wheelies and manuals). Longer chainstays allow for more stability.
  • Reach: The horizontal distance between the top of an imaginary line drawn from the bottom bracket to the saddle and the center of the head tube. This is crucial for bike fit. If the reach is too long, you’ll likely have some back pain from leaning over. If it’s too short, you’ll feel scrunched which won’t be great for pedaling efficiency.
  • Stack: The vertical distance between the center of the bottom bracket and the head tube. This will give you an idea of how high the handlebars will feel.
  • Bottom bracket height: The distance between the center of the bottom bracket and the ground.
  • Wheelbase: The distance between the front axle and the rear axle. A short wheelbase will make the bike feel more maneuverable. A long wheelbase will make it feel more stable.

Now that you have some vocabulary under your belt, let’s roll into bike types (pun intended again).

CROSS COUNTRY / XC BIKES:

Cross-country bikes can be associated with two words: fast and light. These are for riders looking to pedal uphill as efficiently as possible and for folks who love the leg-burning climbs as much (or maybe more) than descending. These bikes are responsive, keep riders in a more upright position compared to other bikes (steeper geometry), and excel on the ascent.

Quick specs:

  • Head tube angle geometry: 69° – 71° (on the steeper side)
  • Rear suspension travel range: 85-100mm or hardtail (no rear shock)
  • Front suspension travel range: 100-120mm
  • Longer chainstays, steep head tube angles, as well as longer stems to put riders into efficient climbing positions.
  • Short wheelbases for maneuverability
  • The most lightweight of the bike types

Yeti’s cross-country steed, the SB100.

Why you may want a cross-country bike:

If you love crushing the uphills but don’t mind sacrificing some suspension and mobility for the downs, an XC bike might be for you. Maybe you love getting out for a few hours at the not-so-steep trail network after work to get that cardio in, or maybe you love road cycling with some added adrenaline. If so, an XC bike may be a match made in heaven.

Why you may want to consider other bike options:

Cross-country bikes are not ideal for steep and rough terrain. If you want to spend days descending technical singletrack or head to the bike park, consider a bike with more suspension, a slacker head tube angle, and a longer wheelbase.

TRAIL BIKES:

When considering the spectrum of mountain bikes, trail bikes are still on the lighter-weight side and more playful on the descent. They offer a medium amount of suspension travel in the fork and the shock for more shock-absorbency on the trails in comparison to XC bikes. They have a longer wheelbase and slacker geometry for more stability at speed and confidence on the descent (and this will make it less likely to go over the handlebars). It won’t climb quite as well as XC bikes due to the increased travel in the rear, but you’ll have a less jarring ride down!

Quick specs:

  • Head tube angle geometry: 66° – 68° (a tad slacker than XC bikes)
  • Rear suspension travel range: 100-140mm
  • Front suspension travel range:: 120-140mm
  • Good for uphill and chunkier downhill – great climbers, capable descenders

Transition’s fan-favorite trail bike, the Scout.

Why this might be for you:

If you love pedaling uphill, enjoying the downhills, and doing a little bit of everything, a trail bike is a fantastic option. It’s the perfect meet-in-the-middle bike for ascending and descending.

Why you may want to consider other bike options:

Trail bikes are better for descending compared to XC bikes, but they still have their drawbacks if you’re seeking more advanced terrain or want to go to the bike park. Steep trails, rock gardens, drops, and other more technical trails will require increased travel both in the front and the rear as well as a longer wheelbase to handle the harsher riding.

ENDURO/ALL-MOUNTAIN BIKES:

Enduro bikes are what some would argue to be the most well-rounded in regards to what they’re capable of. These bikes are typically built with heavier components – and for good reason. They are meant to rip down steep and chunky trails and have the suspension you’ll want to hit drops and maintain speed through rock gardens. Whether you’re at the bike park or your more advanced local trails, an enduro bike will do it all with ease. They won’t climb as efficiently as XC or trail bikes, but if you’re willing to compromise on the uphill, you’ll have a blast riding downhill. In short, these bikes get you up so you can enjoy going down.

Quick specs:

  • Head tube angle geometry: 65° – 67° (slack)
  • Rear suspension travel range: 140-170mm
  • Front suspension travel range: 150-180mm
  • Long wheelbase and reach, low bottom bracket, and slack head tube angle for stability at speed and on the steeps

Pivot’s fun enduro bike, the Firebird.

Why this might be for you:

If you prefer going downhill and don’t care too much about beating your friends on the uphill, an enduro bike could be for you. Their increased weight and long wheelbases will add speed and stability on the downhills for a ripping good time. Don’t be afraid to bring these to the bike park – they’ll be a blast on chunky trails and features you’ll find there.

Why you may want to consider other bike options:

If you want to obliterate climbing times or you prefer mellower trails, enduro bikes might be too much bike. The compression of the suspension will lead to pedal bob and won’t be ideal for climbing fast.

DOWNHILL BIKES:

Downhill bikes are best for, well, going downhill! These bikes have the longest wheelbases, the most travel, the slackest head tube angles, and are built to crush the downhill – essentially armchairs with wheels. You’ll plow through rock gardens, jump off everything in your path, feel more stable at speed, and, hopefully, have fun!

Quick specs:

  • Head tube angle geometry: <65° (the slackest yet)
  • Rear suspension travel range: 200-250mm
  • Front suspension travel range: 180-200mm
  • Dual-crown forks offer tons of suspension for the chunk and large features

Rocky Mountain’s downhill bike, the Maiden.

Why this might be for you:

If you want to spend a lot of time at lift-serviced bike parks, look no further. Parks like Killington in Vermont and Highland in New Hampshire are where these bikes will be at home. With all that suspension, you’ll have a blast riding down everything from jumps and drops to chunky, rocky trails.

Why you may want to consider other bike options:

If you’re looking for a bike that you can pedal uphill, then a downhill bike is not the best option. They are not efficient for pedaling because of all the suspension and slack geometry. Your downhill bike will be happiest and perform the best strictly at bike parks or anywhere else you won’t find yourself pedaling.

We made it through bike types! Let’s dive into some other important features to consider when looking to purchase a mountain bike.

WHEEL SIZE

Back in the day, mountain bikers didn’t have a ton of options when it came to wheel sizes. 26-inch diameter wheels were all there was. As mountain bike technology progressed and trail designs became more advanced, the industry saw a need for bigger wheels. Today, there are two main sizes: 27.5 inches and 29 inches (known as 29’ers).

Riding bikes is sure to put a smile on your face!

27.5 inch

27.5 wheels will have faster acceleration. This means the bike will feel quicker, more controllable, and responsive on the trail. It will turn more quickly in corners and feel snappier than those with 29-inch wheels. A 27.5 bike is more maneuverable. If you ride trails with a ton of pedaling uphill, tight switchbacks, and winding terrain, a 27.5 tire size may be preferable.

29 inch

29-inch wheels take a tad longer to get to speed, but when they do they feel more efficient for longer rides since you don’t have to pedal as much and can coast a bit more. With their larger wheels, 29’ers will also feel a little smoother over chunkier terrain and rollers. But be prepared for the learning curve that comes with cornering. The larger wheels will feel more delayed in corners compared to a 27.5 (don’t work though, you’ll get used to it!). 29ers also weigh more than 27.5s. If weight is your top priority, it’s worth considering a 27.5 to save the ounces.

CARBON VS ALUMINIUM:

Carbon:

Choosing a carbon frame can shave an entire pound off the weight of your bike. You will be able to accelerate more quickly, change lines more efficiently, and won’t have to pedal as much weight up the hills! Modern carbon used for bike frames is durable and has a long life, but it comes with the need for attention to impacts. A force in a concentrated area can crack the frame, which is grounds for replacement as the integrity of the entire frame is then compromised. Don’t worry though, this is a rare occurrence.

A carbon frame will be stiffer than an alloy frame. For cross-country or enduro racing, a carbon frame can feel sharper and more precise compared to an alloy bike – it will respond more quickly in turns and on chunkier trails. However, if you want more forgiveness off of jumps and drops, then alloy is going to provide more flexibility on a structural level.

Alloy:

Alloy frames are a bit heavier than carbon, but they are more easily repaired if they get scratched or cracked. The additional weight is favorable to some folks, as the bikes can feel more stable. Alloy is also more cost-effective. Carbon frames require more engineering, more labor to manufacture, and each frame size requires its own mold. These and other factors are why alloy bikes are almost always going to be cheaper than carbon.

Before you decide on a carbon versus alloy frame, try taking various bikes out for a test ride. Ride an alloy bike, ride a carbon bike, and decide which frame material you prefer for your particular style of riding.

Mountain bikes can take you to some beautiful places!

BIKE BUILDS AND COMPONENTS

When you go shopping for a mountain bike, you will notice that models of the same bike are more expensive than others. This is due to the various build kits that bikes are available in.

Nicer bike builds are made with nicer components – brakes, wheels, dropper posts, etc. – that compose the rest of the bike aside from the frame. Higher-end components often are lighter in weight, offer better performance, and are more expensive.

For more information on common components and all the different models, visit the following:
The Sram hierarchy can be found here.
The Shimano hierarchy can be found here.

TO SUM IT ALL UP

If you take one thing away from this article let it be this: TRY BEFORE YOU BUY. Demoing a bike out on your favorite trail will help you get a feel for each bike you’re interested in. Take a demo bike to a trail that offers a little bit of everything: fast corners, rooty sections, maybe a drop or two if that’s your thing. The more terrain you can test the bike on, the better! Our rentals are great for folks who want to take a bike to the local trails and see if they like it.

Come on in, get on a bike, or meet us at the local trails. If you have any more questions, slide into our DM’s on social, give us a call, or come into the shop.

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