Cart
Whether it’s a gravel bike, fatbike, or city bike, the perfect ride starts well before your first pedal stroke: it begins with choosing the right bike size.
A poorly fitted bike isn’t just uncomfortable—it can impact your performance, compromise your safety, and even cause pain or injuries. Discover how to determine your ideal bike size by considering both your body type and riding style.
Key Measurements for the Perfect Fit
An appropriately sized bike ensures comfort, helps you avoid pain, and allows you to enjoy your rides fully. To find the correct frame size, two measurements are most commonly used: inseam and overall height.
-
Overall height gives a general idea, but doesn’t differentiate between cyclists with long legs versus those with a long torso.
-
Inseam is the most reliable reference, as it directly reflects leg length, which determines saddle height and pedaling efficiency.
By combining these two approaches, you’ll maximize your chances of finding a bike that perfectly fits your body.
Example: A Rider with an Inseam of 80 cm
-
For a road bike: 80 cm × 0.66 = 52.8 cm → you should aim for a frame of about 53 cm.
Note: this measurement applies to all bike types except those where you sit upright, similar to a chair.
-
For a fatbike: 80 cm × 0.59 = 47.2 cm → the ideal frame size will be around 47 cm.
This example shows how a simple calculation can guide you toward the correct bike size with precision.
Comparative Table of Measurements for Adjusting Your Bike
| Measurement | How to Take It | Advantages | Limitations |
|---|---|---|---|
| Inseam | Stand with your back against a wall (keep shoes on), feet slightly apart. Place a book firmly against your perineum, like a bike saddle, then measure the distance from the floor to the top of the book. | Very precise measurement for determining frame size and saddle height. Allows the use of specific formulas for different types of bikes: - Road: inseam × 0.65 / 0.66; - Fatbike: inseam × 0.56 / 0.59 |
Requires some effort to take correctly and may be misinterpreted if the book is not placed firmly enough. |
| Total Height | Stand straight with your back against a wall, then mark the top of your head to measure the distance from the floor. | Simple and quick. Gives a general estimate of frame size. Useful for beginner cyclists who want a quick idea of suitable frame sizes. | Less precise than inseam measurement. Does not account for variations in leg or arm length, which may lead to a suboptimal bike choice. |
| IMPORTANT NOTE: Saddle height corresponds to the distance between the top of the saddle and the pedal in the lowest position (bottom dead center). | |||
Size Guide by Bike Category and Rider Height
Contrary to what one might think, there is no universal size: each bike type (road, city, fatbike, gravel, mountain, etc.) has its own geometry, influenced by its intended use.
For example, a road bike is designed for a lower, more stretched-out position that promotes aerodynamics. In contrast, a mountain bike or fatbike is shorter and more maneuverable, making it easier to handle rough terrain.
Specialized retailers like Moose Bicycle provide size charts, but keep in mind that they are only a starting point. Individual body proportions, such as inseam length, are just as significant—this explains why two people of the same height might need different bike sizes. That’s why it’s always best to test-ride the bike or seek professional advice before making a purchase.
| Cyclist height | City bikes | Road bikes | Fat bikes | Gravel bikes |
|---|---|---|---|---|
| 155 – 167 cm | Frame 41–46 cm (size S, 26" wheels) |
Frame 48–51 cm (50–52 cm if >161 cm) |
Frame 35–38 cm (14–15") up to 41 cm if >161 cm 26–27.5" wheels (size S) |
Frame 47–51 cm |
| 168 – 183 cm | Frame 46–56 cm (sizes M–L, 54–56 cm wheels) |
Frame 51–60 cm (53–57 cm for 169–180 cm, sizes M–L) |
Frame 38–48 cm (15–19") 26–29" wheels (27.5–29" recommended) sizes M–L |
Frame 51–60 cm |
| 184 – 193 cm | Frame 51–56 cm (sizes L–XL, 56 cm and above) |
Frame 57–64 cm (55–60 cm if 183–192 cm, sizes L–XL) |
Frame 48–56 cm (19–22") 27.5–29" wheels (29" ideal) sizes L–XL |
Frame 60–64 cm |
| Important note: These recommendations are indicative. To select the exact bike size, measure your inseam, consider the type of riding, and consult the manufacturer’s guide or a specialist at a bike shop. | ||||
If you’re hesitating between two sizes, keep these simple rules in mind:
-
A smaller size favors maneuverability and a sportier ride, while a larger size provides comfort and stability, especially for long rides.
-
For children, size is determined mainly by height and wheel diameter (26 inches starting from around 1.50 m / 4’11”), but be careful never to choose a bike that’s too big, as it will be challenging to handle and could discourage learning.
Ergonomic Adjustments for Optimal Comfort
Even with a frame that perfectly matches your size, your bike may still lack comfort if specific settings aren’t optimized. Ergonomic adjustments—also known as bike fitting—may therefore be necessary.
Several specialized shops, such as Moose Bicycle, offer this service:
-
Free when purchasing a new bike.
-
Paid if you wish to improve your position on an existing bike.
These often millimetric adjustments help prevent pain, enhance performance, and make every ride much more enjoyable.
Here are some key elements a professional can adjust to fine-tune your bike:
-
Saddle height: allows smooth leg extension without excessive strain.
-
Saddle angle: slightly tilted or neutral, depending on the desired comfort.
-
Saddle fore-aft position: balances weight distribution and pedaling efficiency.
-
Handlebar height: higher for comfort, lower for performance.
-
Stem length: influences posture and bike handling.
-
Handlebar and brake lever angle: crucial to avoid wrist pain and ensure reasonable control.
-
Handlebar width: should match the rider’s body type for better breathing comfort and optimal stability.
Conclusion
Choosing the right bike size and making ergonomic adjustments are fundamental steps to maximizing your enjoyment, safety, and performance on the bike. With these tips, every ride will become a more comfortable and efficient experience. Don’t hesitate to seek expert advice from Moose Bicycle if you’re unsure.