Ridelogic Mountain Bike Fitting

Mountain biking is a great way to get outside, enjoy nature, and get a great workout in. However, if you don’t have a mountain bike with the proper fit, the ride may be uncomfortable and even painful. The other, most important aspect of a great fitting mountain bike is performance. A great mountain bike fit allows you to have the range of motion needed to negotiate technical trail features and flow with the trail. A great fitting bike will make you faster and your rides more fun. In this guide, we’ll go over the different aspects of mountain bike fitting and how you can find the perfect mountain bike and size frame for your body. We’ll also provide tips to help you take measurements yourself.  

Why a Proper Bike Fitting Is Important 

Mountain bike fittings are crucial because they allow the rider to be in the most comfortable and efficient position possible with full range of motion. A good bike fit accounts for the rider’s height, weight, inseam length, and other measurements. Making the correct adjustments to the frame size, crank length,  saddle height, handlebar height, and stem length helps the rider achieve a more fun and productive cycling experience.

If your mountain bike and size frame fits your unique proportions, it results in a more enjoyable ride that improves performance while reducing the risk of injury. Riding in the correct position puts less strain on the body and allows you to focus on the trail. It also helps you pedal more effectively with better power transfer.

Understanding the Factors of Mountain Bike Fitting

When it comes to mountain bike fitting, there are a few key factors to consider:

Rider Area Distance (RAD)

The Rider Area Distance, RAD, is the most important measurement for fitting your mountain bike to shred trails. Using your custom measurements, you can calculate an optimal distance between your feet and hands. This gives you the best range of motion while riding difficult terrain. 

Reach

One of the most critical factors is reach, which is the horizontal distance from the center of the bottom bracket to the middle of the headtube. This measurement directly affects how upright or stretched out you are on the bike. Stem length can be adjusted on a bike with a reach that is not ideal, but only until it starts to affect handling. 

Stack

Stack is the vertical distance from the center of the bottom bracket to the top center of the head tube. This helps determine how high you can have your handlebars. If you have really long legs, you may actually want to size up a frame so you can get one with a taller stack height to avoid having too much drop from the seat to the handlebars. Also those riding longer travel bikes and getting fit for enduro riding may want a taller stack as well. 

Proper Seated pedaling position

The following photo shows a good riding position for trail riding. Note the fairly upright torso and not super extended arms. The angle between arm and torso should be around 50-70 degrees. This position will be comfortable to pedal in and then give you access to the full range of motion needed to hit rollers, roots, rocks, corners, and downhills. For Climbing you’ll be able to climb long distances comfortably and quickly be able to move your weight forward when needed for steeper sections. For cross country racing, you would expect to have your arms further forward more similar to a road bike. The arm to torso angle will be closer to 90 degrees for that type of riding. This photo shows proper position for all-around trail riding on longer travel bikes.

Standover Height

Next is the standover height, which is the distance between the ground and the top tube. Be sure there is enough clearance between the top of the frame and your crotch so you can get on and off the bike with no obstruction.

Seat Height 

Another aspect to consider when fitting a mountain bike is seat height. It measures the distance from the center of the bottom bracket to the top of the saddle. You want a seat height appropriate for your leg length and riding style.  You can see from the photo above the approximate 135 degree angle in the leg when at the lowest position of the pedal stroke. This is ideal, but many mountain bikers are opting for lower seat heights. This may or may not work for everyone. 

You can measure each of these factors yourself, use our mountain bike fit calculator, or check the mountain bike size guide provided by the manufacturer. At Zinn Cycles, we can help you choose the best frame size to get the perfect fitting mountain bike. The relationship between your body and your bike is pivotal for aggressive riding. If your bike is too long or too small, you won’t have the proper range of motion to aggressively pump over obstacles, carve fast corners, and handle steep descents. 

At Zinn Cycles, we utilize the RideLogic™ fit system to create the perfect mountain bike frame size and get the perfect cockpit dimensions to optimize your ability to shred trails. You can get an in-person RideLogic fitting at our store in Lousiville, Colorado.

What To Measure For the Perfect Bike Fit

Finding the perfect bike fit is critical for having a comfortable, high-performance bike. To achieve this, you will need a few key measurements to determine an accurate mountain bike fitting. 

• The first is the sternal notch-to-floor measurement, which is the vertical distance from the bottom of the sternum to the floor. 
  • To get this measurement, stand up straight and face a wall with your feet 2 inches apart and your toes touching the wall. Place the eraser side of a pencil to your sternal notch facing outward and mark the wall with it. Measure up from the floor to the mark.

• The second measurement is your arm length, which is the distance from the lateral tip of your shoulder blade to your wrist bone. You can measure this by holding your elbow straight and your arm out. 
  • To get an accurate measurement, we suggest you have a friend assist you.  

• Finally, you need to know your inseam length. Place your back against a wall with your feet shoulder-width apart and flat on the ground. 
  • Take a ruler or measuring tape and measure the distance from the crotch to the floor. This measurement will give you the inseam length to help calculate the right mountain bike and size frame.

Once you have these three measurements, you can use a mountain bike size guide or bike fit calculator to find the right bike fit. 

Get a Custom Local Mountain Bike Fitting in Colorado

If you are serious about finding the perfect mountain bike, getting a custom fitting will take your performance to the next level. At Zinn Cycles, we can provide you with our years of expertise to create the custom bike you’ve always wanted. Working with our professional bike fitters will ensure that your bike is tailored specifically to your body and riding style for maximum comfort and performance.

With a custom mountain bike fitting, you can expect to attain the optimal riding position based on your measurements and cycling experience. Our experts here in Boulder, CO, will also evaluate the type of terrain you plan to ride on and help you achieve peak performance. With this information, we can recommend the best bike dimensions and create a custom mountain bike size frame that fits your body and exceeds your expectations. 

Now that you know the different aspects of mountain bike fitting, it’s time to find the perfect bike. Feel free to submit your measurements, or for a more comfortable and safe ride, contact us or call 303-499-4349 to request a consultation. You can also book an in-person RideLogic Mountain bike fitting at our shop.