The most common method to categorize mountain bikes is by the type of riding for which they’re designed. The primary mountain biking riding styles are cross country (XC), trail, all-mountain, and downhill (DH). The order is important here because there is a relatively linear progression in design features from cross-country through downhill. This article is intended to help distinguish between the middle two categories, trail bikes and all-mountain bikes.
Trail mountain bikes are probably the most popular category, as they are designed for conquering a wide variety of terrain. While they may not climb quite as well as their cross-country brethren, they still climb very well and descend with equal aplomb. If cross-country mountain bikes are all about speed, trail bikes are about maximizing fun and efficiency over varied terrain.
All-Mountain bikes are also referred to as enduro mountain bikes. The term enduro comes from the world of mountain bike racing and refers to a competition that has timed downhill stages and untimed uphill stages. Therefore, these bikes are designed with long and technical descents in mind but are still capable of being pedaled up hills. All-Mountain bikes will generally have more cushy suspension than trail bikes, but will also generally be heavier as a result.
Key Differences Between Trail Bikes and All Mountain Bikes
Okay, let’s get into the nitty gritty. What are the key differences between trail bikes and all-mountain bikes? The differences can be lumped into two areas, differences in the frame and differences in the components.
Frame Design and Construction
There are there primary factors to discuss with regard to full suspension mountain bike frames: 1) frame geometry, 2) suspension design, and 3) frame materials. We’ll just focus on the first two here since frame material arguably has the least impact on the distinction between trail bikes and all-mountain bikes. For a brief overview of the primary frame materials, see our article on Bike Frame Materials.
Okay, so let’s talk about frame geometry a little bit. With regard to the difference between trail bikes and all-mountain bikes, we’re primarily just talking about two numbers, the head angle and the seat angle. The head angle is merely the angle of the head tube relative to the ground. Head angles run from as high as 73 degrees on cross country mountain bikes down to about 63 degrees on downhill mountain bikes. While 10 degrees may not seem like a wide range, head angle does have a dramatic impact on bike handling (steering response in particular) because, of course, the steer tube of the forks runs through the head tube of the frame. Likewise, seat angle is just the angle of the seat tube and, similarly, goes from steepest on cross country mountain bikes to slackest on downhill bikes.
Suspension design for full suspension mountain bikes is a huge topic so we won’t be covering it in depth here. The primary aspect of suspension design we want to consider in order to distinguish between trail bikes and all-mountain bikes is merely the amount of suspension. Modern all-mountain bikes generally have 6″-7″ of travel and trail bikes have just slightly less, perhaps averaging 5″-6″ of travel. I would argue that any full-suspension mountain bike with 4″ of travel or less would fit best into the cross-country category but that doesn’t mean that there aren’t mountain bike manufacturers who make bikes with this amount of suspension and call them trail bikes.
Although I didn’t specifically mention weight above as one of the primary differences, it does end up being a distinguishing factor to some extent. While some, or even most, all-mountain bike frames may weigh slightly more than those of trail bikes, the weight difference in the frames is minor compared to the weight difference in the components. More suspension generally means more weight and often other components (e.g., wheels) are beefed up on all-mountain bikes, further increasing their weight over trail bikes.
As you can see, trail bikes and all-mountain bikes have much more in common than distinguishes them. However, I think that the observations made above generally represent the consensus view as to the primary differences between trail bikes and all-mountain bikes.