Mountain Bike Frame Geometry
In the context of mountain biking, "reach" and "stack" are two key measurements that describe the geometry of your bike's frame. They’re important factors in determining how a bike fits and feels.
Reach: refers to the horizontal distance from the center of the bottom bracket (the point where the crankset axle is located) to the center of the head tube (the tube at the front of the frame where the fork is attached). It essentially measures how far forward the rider's torso will be positioned when riding the bike. Reach is a critical measurement for determining the bike's cockpit length and how stretched out or upright the rider's riding position will be. A longer reach typically results in a more stretched-out riding position, which may provide better stability at high speeds and improved control on descents. Reach measurements can vary significantly between different mountain bike models and sizes, so consider your preferred riding style and understand your body proportions when choosing a bike with reach to match.
Stack: refers to the vertical distance from the center of the bottom bracket to the top of the head tube. It measures the height of the front end of the bike frame relative to the bottom bracket. Stack height determines how high or low your handlebars will be positioned relative to the saddle. A taller stack measurement results in a more upright riding position, which may be more comfortable for long rides or riders who prefer a more relaxed riding posture. Stack measurements can also vary between different bike models and sizes, so consider your riding position and comfort when determining the appropriate stack height.
Reach and stack influence your riding position, comfort, and control. It's important to consider both measurements when selecting a mountain bike to ensure a comfortable and enjoyable ride. Remember, calculations are helpful, but there is NO substitute for test riding bikes in order to find the one that just feels right!
