Mountain bikes have been evolving since their origins in the early 1970s. In the last twenty years they have improved drastically, with new technology fuelling the growth of the industry. Over the years, mountain bikes have diversified with unique geometry that suits the different styles of riding and different types of terrain. Modern all mountain (AM) bikes have benefited the most by best utilizing all the recent technology breakthroughs. Carbon frames, new wheel sizes, and adjustable geometry have truly made most modern all mountain bikes applicable to multiple styles of riding and riders.
Shopping for a mountain bike is easier if you know what kind of rider you are and what trails you love. But, you may find the discipline-specific bikes and options confusing, and if you are new to riding or just starting to explore the trails, potentially limiting to how you'll eventually want to use them. The boon for the consumer is, with an AM bike, you can now pretty much buy one bike to do it all.
Here are the three types of riding that all mountain bikes turn into one:
All mountain crossover
All Mountain / Trail AM bikes have blossomed into the most dynamic and useful styles of bikes out there. With the evolution of the wheel (yet again), trail bikes have welcomed the 27.5" wheel, finding a benefit to efficiency as well as handling and control. They are most commonly found with 120mm to 150mm of travel in a full suspension setting. The so-called Swiss army knife of the bike family will keep up with you on full-day backcountry rides as well as cruising around your local trails. An AM is a great climbing bike that can handle some of the bumps and jumps you may want to find on the way down. A more neutral head angle gives you the best of both worlds for handling and efficiency. With the all mountain / trail bikes category exploding in growth, there has been a development of sub categories that brands have been playing with to increase the trail experience for riders all over the globe.
Cross Country (XC) Cross country bikes often use the largest of the three wheel diameters with a standard of 29". The bike's geometry places the rider towards the front of the cockpit and will give the most efficient and fastest climbing ride available. XC bikes are lightweight and usually range from 80mm to 120mm of travel. If getting your heart rate maxed and riding for fitness is your style, a cross country bike will be the only option.
Downhill (DH) Gravity fed machines that will endure the most abuse out of the bunch. Typically 200mm of travel, these bikes are most commonly chosen for downhill racing, cruising laps in your local bike park and shuttling the mountains with your buds. Although it sounds easy, riding downhill for long periods of time can test the body as much as a crossfit class. The forecast is calling for a 27.5" takeover in this category as well. Some brands are dragging their feet but it is inevitable.
Adjustable geometry of AM bikes
Subtle changes in geometry can have profound effects on the characteristics of a bike. Making the head tube more slack, for example, can greatly improve a bike's ability to descend. All it takes is a couple of degrees of adjustability and your all mountain bike will both climb and descend astonishingly well. Over the past few years most bike brands have introduced their own version of adjustable geometry with great success.
Rocky Mountain may have one of the best adjustable geometry systems in their patented Ride-9 geometry chips. Ride-9 allows each rider to tune its geometry, be it based on the nature of the terrain, rider weight, ride preference from aggressive to efficient, as well as manage the curve rate of the shock throughout its stroke. This will help take the stress off of the shock as geometry changes and let it perform the way it was designed. Check out the breakdown of Rocky Mountain's Ride-9 and how it works.
This adjustability is absolutely key to why an all mountain bike will be your next bike. It allows your one bike to be ridden in all three of the genres we mentioned. A few years ago, even if the bikes had adjustable geometry, they were still limited in what they could do, whereas now, new all mountain bikes are strong enough to take a decent amount of DH riding, yet light enough to pedal an XC trail. This means more fun for the rider as they are not as limited to specific trail choice or riding style.
Wheel options for AM bikes
All mountain bikes make the best use of all the available MTB wheel sizes and options: 27.5" (a.k.a. 650b), 29", and Plus. Most bike brand lineups have the 130-160mm travel bikes available in all wheel sizes, and for very good reason; an AM bike's adjustable geometry, combined with ability to accommodate variable wheel sizes, further allows it to be used for almost every type of riding.
To practically put it, if you are a climber most days, but maybe do the odd bit of aggressive descending, buy a bike with 29" wheels, 130mm of travel, and adjustable geometry. On the other hand, if you favor the descents more, but still have to pedal in, you can get a 150mm 27.5" bike. The main point is wheel options compliment the adjustable geometry found in all mountain bikes, whereas in XC bikes you are being limited to mainly 29" wheel options with limited adjustment and steep geometry.
Advertisements and reviews often pitch one bike for one purpose, and sponsored pro riders can afford to do just that. In an ideal world, we would have enough money to buy a bike specific to every type of riding, but sadly this isn't possible for most of us. For the average consumer, geometry adjustability and wheel size choice make all the difference - and that's why your next bike should definitely be an all mountain one.
Here are some suggestions for affordable do-it-all all mountain bikes:
Kona offers the price point option for trail riders on a smaller budget. This bike will come in with a little heavier overall build, but gives you the stability and strength to handle some of the more aggressive turns and hits along the way. Adding a dropper post will increase the price off the floor, but consider it a must do before you buy.
Giant crushes the competition with more price sensitive options that offer a great bang for your hard earned buck. Giant has designed this bike to be able to attack any terrain in any condition and claims this will be ready for tough climbs and rowdy descents.
27.5" trail bike of choice from Rocky Mountain is the Thunderbolt. Utilizing Ride-9 geometry chips - two interlocking chip inserts that move on two separate axes - the Thunderbolt gives the rider almost any desired head angle within 2 full degrees, as well as adjustments to the bottom bracket height and suspension stroke. Completely tuneable to the trails you are riding and the terrain you're approaching, the Thunderbolt is a fantastic choice for a do-it-all bike.
Transition is a smaller company based out of the U.S. Pacific North West. The guys at Transition are focused on making sure riders are having fun on their bikes no matter what the wheel size or intended use. Transition promotes simple bike designs that work well, as well as partying in the woods. The Smuggler sports a short chainstay and aggressively slack angles, giving you a very lively feel in and out of corners and the ability to descend a lot harder than most 29ers. Jumping a 29er has never felt easier or given me a bigger boost in confidence than when I first rode a Smuggler. Riding a Smuggler, you get to enjoy the efficiency of the big wheel on the climbs while blasting corners and boosting every obstacle in sight on the way back down.