Single-speed mountain bikes are not for the faint-hearted. The elegance, simplicity, durability, light weight and low cost of single-speeds has earned them a loyal following among urban tricksters and daily commuters, but mountain bikers ride on mountains, and climbing hills on a bike with one gear can be a real challenge. For some hardy riders, though, that challenge is irresistable, and a small community of riders has embraced the single-speed bike as their mountain bike of choice. If you’re up to the challenge or if the trails in your area don’t feature leg-busting climbs, a single-speed might be right for you.
Single-Speed or Fixed Gear: What’s the Difference?
Many people use the terms single-speed, fixed-gear, and “fixie” interchangeably. There’s still a difference, technically. A single-speed bike has one front chainring and one rear drive gear, so you only have one riding gear. It will still have a freewheel, so you can hold the pedals stationary and coast.
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A true fixed-gear bike has no freewheel, so if the rear wheel is turning, the pedals are turning. Fixed-gear bikes may not have brakes at all: the rider uses the pedals to stop the rear wheel. True fixed-gear bikes can be challenging to ride, especially downhill, as your legs have to keep up with the pedals. Injuries from pedal strikes can happen if you slip at the wrong time.
If you’re shopping for a single-speed bike and someone offers you a “fixie” there’s a good chance that they’re using the term to describe a freewheel single-speed. It’s still a good idea to make sure there’s a freewheel, unless you’re ready to keep up with those spinning pedals!
About Gears and Wheels
A single-speed bike has only one gear combination, so you need to have the right one. single-speed gears are described in two ways. Many single-speeders simply use the number of teeth on the front and rear gears: a 32 x 18 single-speed has a front chainring with 32 teeth and a rear cog with 18 teeth. Some also use the ratio of front to rear rotation: 2:1 ratio means that for every turn of the pedal the rear wheel makes two full rotations. 2:1 is a common starting point. Lower ratios mean that pedaling is easier, and are more appropriate for climbing hills. Higher ratios feel “heavier”, making it harder to climb or to get the wheels moving, but help you carry speed better on flat surfaces.
Back in the days of 26” wheels either of these measurements gave riders a good idea of how much power they would have to put on the pedals to move the bike. The introduction of multiple wheel size standards changed that. With the same gear ratio a 27.5” wheel will take more effort to turn than a 26” wheel and a 29” wheel will take more effort to turn than a 27.5” wheel.
Unless you’re very familiar with how a given gear ratio feels with a specific wheel size, your best bet is probably to try it out and see. You’ll be in that gear a lot – any time you’re on the bike – so it has to be comfortable on the terrain you ride. You don’t have to try out the specific bike you’re considering, but you should try to take a spin on a bike with a similar gear ratio and the same wheel size.
The Rest of the Bike: What to Expect
There are not many fully built single-speed mountain bikes on the market. Single-speed riders tend to be experienced cyclists and many prefer to assemble their rides to their own specifications. There are still some fully built options from major manufacturers, and if you’re looking at built single-speed bikes, there are a few things you can expect to see.
- Hardtails – Single-speed riders prioritize simplicity, and that means hardtail frames.
- Short travel or rigid forks – Most single-speed bikes that have front suspension use forks with 100 to 130mm of travel, and many use rigid forks.
- Traditional geometry – The trend in modern mountain bikes is toward “slacker” designs that rake the fork forward and place the front wheel farther in front of the rider for more stability on steep downhills. Head tube angles of 65° to 66° are common on modern trail bikes. Single-speed bikes tend to use more traditional designs with head tube angles closer to 70°.
- Minimalist builds – In keeping with the simplicity-first ethic that drives many single-speed riders, many built bikes will use high quality parts but with as few frills as possible.
- Low weight – Stripping off chainrings, cogs, derailleurs, and shifters doesn’t just keep a bike looking sleek. All those parts weigh something, and single-speed bikes are generally a lot lighter than their geared counterparts.
All of these features are compatible with riding on smooth trails without extremely steep climbs or descents, which is consistent with the way single-speed mountain bikes are usually used.
The Best single-speed Mountain Bikes
If you’re looking for a single-speed mountain bike you’ll be reviewing a fairly short list of built-up options. You’ll want to consider these options, and you may consider assembling your own build as well!
Best All Around Single-Speed Mountain Bike: Niner SIR 9
- Frame Material: Steel
- Fork: Fox 34 Float, 120mm travel
- Wheel Size: 29”
- Brakes: Shimano XT M8100 Hydraulic Disc
- Gear Ratio: 32 x 20
- Seatpost: KS Lev Dropper
- Head Tube Angle: 68°
- Weight: 28.8 lbs.
- Price: $3500
If you want to buy a fully assembled off-the-rack single-speed mountain bike designed for serious trail riding, you won’t find an option better than this. SIR stands for “Steel is Real”, and the frame at the heart of the SIR 9 is hand-welded from Reynolds 853 steel tubing, taking full advantage of the renowned durability and shock absorption capacity of high grade steel frames and providing a sleek slim-tubed build. The Fox 34 float fork brings high-end tunability that maximizes its 120mm of travel. The 68° head tube angle is still on the steep side for trail riding by the most modern standards, but it won’t send you over the bars on the steeps: only a few years ago 68° was considered quite slack and was used on hardcore trail bikes.
The components on the SIR 9 are set up for serious mountain biking: this is not an urban cruiser with fatter tires, it’s a true mountain bike. Shimano XT hydraulic disc brakes with 180mm front and 160mm rear rotors provide high end braking power and control. A stock tubeless setup with Schwalbe’s highly regarded Nobby Nic trail tires provides maximum traction with minimum drag. If you’re looking for a bikepacking ride, the SIR 9 comes with a full range of mounts for almost any frame-mounted luggage carrying system. The SIR 9 is compatible with either single-speed or geared setups, so if you decide that single-speed riding isn’t for you, you can convert your bike to a high-end geared hardtail.
The only serious disadvantage of the SIR 9 is the price tag, which is right up there with what you’d pay for a premium geared hardtail. If you want a true top-of-the-line single-speed mountain bike, though, the quality of this bike and its components fully justifies the cost.
Best Single-Speed Mountain/Urban Crossover: Surly Lowside
- Frame Material: Steel
- Fork: Surly Lowside Rigid
- Wheel Size: 26”
- Brakes: Tektro Hydraulic Disc
- Gear Ratio: 32 x 17
- Seatpost: Fixed
- Head Tube Angle: 70°
- Weight: 29 lbs. 15 oz.
- Price: $1250
Minnesota-based Surly has always embraced niche markets, and they’ve always had some single-speed bikes in their lineup. The Lowside, Surly’s current entry in the single-speed mountain bike market, embraces the traditional style, with a rigid fork, 26” wheels, BMX-style bars, a slim-tubed steel frame, and relatively steep geometry. The primary “mountain” feature of this mountain bike is the tires. Surly is a leading maker of fat bikes, and while the 3.0” Surly Dirt Wizard tires on this bike are not quite in fat bike territory they are certainly plus-sized, providing plenty of contact surface and aggressive knobs for traction. They are also big enough to absorb some shock, though they won’t provide the fully cushioned ride of a full-on fat bike.
The simplicity of the Lowside doesn’t leave it with a lot of components to talk about. The SRAM NX crank is straight from the mountain bike parts box and will stand up to real abuse. The Tektro hydraulic disc brakes may not have the bling factor of their upmarket equivalents from Shimano and SRAM, but they keep the price down and they will stop you effectively. The Lowside also gives you upgrade options if you decide that simplicity has its limits. The frame is dropper post-ready, the head tube will accept a short-travel suspension fork, and there’s a derailleur hanger to support geared riding.
The Lowside is marketed as the big-kid version of your first bike. It’s perfectly suitable for urban riding, whether you’re ripping up alleyways and throwing stunts or just riding to work or cruising down to your favorite craft brewery. It’s also quite at home on singletrack, making it a perfect all-around ride for both around town and trail riding. The rigid fork and steep geometry mean you probably wouldn’t want to take it down the technical steep stuff, but even there, if your kung-fu is up to the task the bike will deliver. It’s also a relatively affordable entry to the world of single-speed mountain biking that gives you the option of converting to a geared setup with suspension, an attractive feature for riders who want to try single-speed riding but aren’t sure if they want to commit to it!
Best Frame for a Custom Single-Speed Build: Santa Cruz Chameleon
- Frame Material: Aluminum or Carbon
- Wheel Size: Fits 27.5 or 29”
- Recommended Fork: 120-140mm
- Head Tube Angle: 67.3°
- Weight: Aluminum 4.6 lbs, Carbon 3.75 lbs
- Price: Aluminum $749, Carbon $1299
Single-speed riding is demanding, and many of the riders who turn to single-speeds are experienced cyclists who have very specific expectations. For these riders a custom build has enormous appeal. Selecting the components that suit your riding style and the terrain you ride produces a bike specifically designed for you, to your specifications.The Santa Cruz Chameleon is the ultimate in hardtail flexibility. It will accommodate single-speed or geared builds with 27.5” or 29” wheels. The frame is available in carbon or aluminum models. The chainstays are wide enough to fit plus-sized tires, if you roll that way. Whatever you want your single-speed hardtail to be, the Chameleon will live up to its name and provide it!
The Chameleon is an extraordinarily versatile frame, but it’s definitely oriented toward mountain bikers. The frame can accommodate forks with up to 5.5” (140mm) of travel, and the 67.3° head tube angle provides a distinctly modern geometry oriented toward steep, technical riding. If you want to ride your single-speed on seriously gnarly trails you can build your Chameleon into a fully capable trail bike. If you want to ride long distances on groomed trails the Chameleon will change its color and fit right in!
The Bottom Line
Single-speed bikes are a niche market and single-speed mountain bikes are a smaller niche within that niche. These smaller markets are often served by boutique bike makers, and single-speed mountain bikes are no exception. I haven’t included these bikes here because most of them have limited production capacity and small dealer networks, and their bikes are often hard to order or to find in shops. If you have a regional bike maker that’s popular in your area or if you see a small-brand bike available, they are certainly worth considering.
Single-speed mountain bikes aren’t right for everyone, but they might be right for you. You’ll have to consider your own fitness, the type of riding you do, and what your approach to cycling is. If you want simplicity and getting back to the roots of the sport appeals to you, a single-speed might be your perfect ride, especially if you’re a strong rider or if your riding doesn’t include steep climbs. It will be a challenge, but facing and overcoming challenges is what cycling is all about!