The MTB Reach Calculator is a tool designed to help cyclists find the perfect bike size and fit. Reach, in the context of mountain biking, refers to the horizontal distance from the bottom bracket (the part of the frame that houses the crankset) to the top of the headtube (where the fork passes through the frame). It’s a critical measurement that affects how a bike feels and handles. By calculating the optimal reach, riders can select a bike that offers better control, comfort, and efficiency on the trails.
Formula of MTB Reach Calculator
The formula to calculate MTB reach is as follows:
Reach (R) = (Stack Height (S) + Handlebar Width (H)) - (Stem Angle (A) x Cosine (Stem Angle))
Where:
R= Reach (in millimeters)S= Stack Height (in millimeters) – distance from the bottom bracket center to the head tube topH= Handlebar Width (in millimeters)A= Stem Angle (in degrees)Cosine (Stem Angle)= mathematical function based on the stem angle
This formula takes into account the stack height, handlebar width, and stem angle to provide a reach value that can guide riders in choosing the right bike size and setup.
General Terms Table
| Rider Height (cm) | Typical Stack Height (mm) | Typical Handlebar Width (mm) | Common Stem Angle (Degrees) | Estimated Reach (mm)* |
|---|---|---|---|---|
| 150 – 160 | 560 – 580 | 720 – 740 | 6 – 8 | 360 – 380 |
| 161 – 170 | 580 – 600 | 740 – 760 | 6 – 8 | 370 – 390 |
| 171 – 180 | 600 – 620 | 760 – 780 | 6 – 8 | 380 – 400 |
| 181 – 190 | 620 – 640 | 780 – 800 | 6 – 8 | 390 – 410 |
| 191+ | 640 – 660 | 800 – 820 | 6 – 8 | 400 – 420 |
*Estimated Reach values are provided for reference only and assume a neutral stem angle effect for simplification. Actual reach will vary with specific stem angle and cosine adjustment.
Example of MTB Reach Calculator
To better understand how the MTB Reach Calculator works, let’s consider an example:
Suppose a rider has a bike with a stack height of 600mm, a handlebar width of 700mm, and a stem angle of 45 degrees. Using the formula provided, the reach can be calculated as follows:
- Convert the stem angle to radians for the cosine function (optional step based on the calculator’s design).
- Apply the formula to find the reach.
This practical example helps riders visualize how changing different variables can affect the overall reach and, consequently, the bike’s fit and performance.
Most Common FAQs
Reach is the horizontal distance from the bottom bracket to the top of the headtube. It significantly influences how a bike fits a rider and impacts handling and comfort.
Wider handlebars can increase the effective reach of a bike, offering more control and stability, especially on technical terrains. However, the optimal width varies depending on the rider’s size and riding style.