Mountain Bike Frames

Mountain Bike Frame Buyer's Guide

The heart and soul of each and every complete mountain bike is the frame. Different frame characteristics, such as suspension design, geometry and weight all influence the way a bike will handle, fit and feel. There are many models and styles to choose from to suit every rider and riding application. Purchasing a new frame can drastically improve your mountain biking experience and rejuvenate any rider's desire to get out on the trail.

Types

Mountain bike frames vary substantially depending on the type of riding they are intended for. Pick the category that suits your riding style best.

Cross-Country Mountain Bike Frames - Cross-country frames (also known as "XC frames") are intended for use on cross-country trails, whether recreational or competitive. They come in two varieties - full-suspension or hardtail. In either case, suspension travel will very rarely exceed 4.5-inches. 26", 650b, and 29" wheel sizes are available. They climb hills very well, but don't offer as much comfort on the way back down as a longer travel bike will.

Trail Mountain Bike Frames - Trail frames (commonly referred to as ""all-mountain frames") work well for many applications. To be classified as a trail bike, frames have anywhere between 4.5 and 6-inches of suspension travel. If you're looking for a frame that can "do it all," this is the right type to consider. While it won't be perfect for everything, it can likely get the job done.

Freeride Mountain Bike Frames - Freeride frames are full-suspension bikes intended for use on aggressive trails and at gravity-oriented bike parks. Suspension travel is typically in the 5.5 to 7-inch range.

Downhill Mountain Bike Frames - Downhill frames are made to go down hills, fast. These frames are always full-suspension with 7 to 10-inches of suspension travel in the rear to absorb big impacts when landing drops or smashing through rock gardens.

Dirt Jumping Frames - Dirt jumping frames are first and foremost made for dirt jumping, but they also work very well at the skatepark and for most slopestyle applications. Hardtails are the most common, but full-suspension options also exist. Suspension travel is typically less than 4-inches.

Materials

The overall feel of a bike is largely dependent on what material(s) the frame is made of, so this is an important consideration.

Aluminum - Aluminum is light, stiff, and affordable, making it the most commonly used frame material. Because it is so stiff, aluminum bikes are characterized by a slightly rougher ride than those made from chromoly or titanium.

Carbon Fiber - Carbon fiber is basically very thin strands of carbon that can be twisted and woven together, like cloth. To make carbon fiber take on a permanent shape, it can be layered over a mold, then coated with a stiff resin or plastic. It is among the lightest materials and is commonly used for high-end cross-country and all-mountain bikes. More recently it has found its way into some downhill and freeride frames. Because carbon technology is advancing very quickly, costs are being lowered and durability is increasing.

Chromoly Steel - Chromoly (a steel alloy) is lighter than high-tensile steel, strong, responsive, and offers a relatively supple ride. However, it is heaver than aluminum, carbon, and titanium.

Titanium - Titanium (also referred to as "ti") is very light and stronger than steel. It is also very expensive, and for this reason is only seen in very high-end or custom frames. Titanium also offers a smooth ride because it flexes well.

Material Combinations - If a frame is made of more than one material, it is usually carbon fiber and a metal - either steel, aluminum, or titanium. Material blends are not common, but constructing various parts of a frame from different materials is (ie - a carbon fiber front triangle with an aluminum swingarm). A frame made out of more than one material can help provide better stiffness, compliance, or damping in specific areas.

Sizes

The most common way to size a mountain bike frame is "standover" height, also known as inseam clearance. You want plenty of room between you and the top tube when you come to a stop, especially on uneven surfaces. As a rule of thumb, there should be at least four inches of clearance from the top of your inseam to the top of the top tube. Note that for some categories and styles of bikes, the distance measured may be much larger than four inches. This is okay, provided the length and cockpit area of the bike fit you well.

Frame sizes are typically measured from the center of the bottom bracket to the center of the top tube. Most manufacturers provide suggested sizing charts, and because models vary so much between categories, we recommend searching for the chart specific to the bike you're interested in. It's important to note that everyone has different riding preferences, so it's best to test out a variety of sizes before making a final decision.

For more detailed sizing information, visit the buyer's guide specific to the type of frame you're interested in: Cross-Country, Dirt Jumping, Downhill, Freeride, or Trail.

Wheel Size

It's very rare to see anything other than 26-inch wheels on downhill, freeride, and dirt jump frames. However, if you're considering a cross-country or trail bike, you'll need to decided between 26-inch, 650b, and 29-inch wheels. For many years, 26-inch wheels were the standard on these types of bikes, but recently 650b and 29-inch wheels (commonly known as "29ers") have become increasingly popular. The larger diameter wheels roll over obstacles more easily and the tires can be run with less air pressure, providing better traction. On the other hand, larger wheels are heavier, more flexible, and there are fewer component and tire choices available. If you're on the fence about wheel size, we highly suggest testing all sizes before making a purchase.

Things To Look For

When shopping around for a new frame, compatibility with your old parts is the first thing to consider. There are four areas to keep in mind: headtube, bottom bracket, rear axle and seat post size must all be identical to those of your current components if you wish to transfer them over seamlessly. Next, choosing a frame that is designed for the type of riding you will be using it for will maximize your bike's overall performance thanks to a purpose built geometry. Finally, frames tend to outlive most components on a bike, so taking the time to find a model that appeals to you both practically and visually is very important.

How Much To Spend

Mountain bike frames generally range in price from $450 to $4000.

Models in the $450-$1000 range are mostly hardtails, available for cross country, dirt jump and trail applications, but there are also dual suspension designs to choose from.

Moving up to the $1000-$2000 dollar range, aluminum and chromoly frames are available for all riding disciplines, as well as some carbon fiber hardtails. In this price range, dual suspension frames begin to incorporate more sophisticated suspension designs, as well as superior rear shocks.

Frames in the $2000-$3000 range are high performance designs, generally dual suspension and made from aluminum these models use the same suspension technology and geometry as the most expensive models.

Finally, models costing more than $3000 dollars are either top of the line aluminum, or carbon fiber dual suspension bikes intended for competitors and devout riding enthusiasts.

Product Reviews

Before buying, be sure to do your research and read product reviews. Reviews are a great way to find out specifics about a particular model, user impressions, and things to watch out for. After you've purchased a product and had enough time to thoroughly test it, we encourage you to leave a review for other people to see when they are researching bikes and parts on the web.

We hope you've found this information to be helpful. If you have a question that isn't answered in this guide, our mountain bike forums are a great place to get advice from knowledgeable riders. Your local bike shop is also a great resource.