Height charts are a good place to start when sizing a gravel bike, but two riders of the same height can need different sizes. The most reliable way to choose is to compare stack and reach with a bike you already ride comfortably. This guide covers both methods, with a worked example from our own size chart.
Gravel bike size chart by height
Every brand publishes a height chart. Use it to find the one or two sizes to look at closely. Ours uses the same ranges across all three models:
| Rider height | Gamma Race, Gamma X and N1 |
|---|---|
| 155 to 165 cm (5’1″ to 5’5″) | 48 |
| 165 to 172 cm (5’5″ to 5’8″) | 51 |
| 172 to 180 cm (5’8″ to 5’11”) | 54 |
| 180 to 188 cm (5’11” to 6’2″) | 56 |
| 188 to 195 cm (6’2″ to 6’5″) | 58 |
| 195 cm and up (6’5″ and up) | 61 |
Height charts don’t know your leg length, your flexibility or how you like to sit on the bike. If you are near the edge of a range, or your proportions are unusual, move on to stack and reach.
Sizing with stack and reach
Stack is the vertical distance from the center of the bottom bracket to the top of the head tube. Reach is the horizontal distance between the same two points. Together they describe where the front of the bike sits relative to the pedals, which sets your riding position more directly than any frame size label.
Look up the stack and reach of a bike you already ride well. Most brands publish them, and you can measure them if yours doesn’t. Then find the size of the new bike with the closest numbers. A higher stack gives a more upright position. A longer reach stretches you out.
Our gravel bike geometry guide explains the other numbers on a geometry chart, including wheelbase and bottom bracket drop.
Worked example: a 178 cm rider
Say you are 178 cm tall and your current gravel bike has 580 mm of stack and 390 mm of reach. The height chart points to a 54.
| Size 54 | Stack | Reach | Compared with your bike |
|---|---|---|---|
| Gamma Race | 585 mm | 393 mm | 5 mm taller, 3 mm longer |
| N1 | 560 mm | 388 mm | 20 mm lower, 2 mm shorter |
The Gamma Race 54 is almost identical to your current bike. You could keep the same stem and handlebar height and feel at home. The N1 54 has a similar reach but puts the bars 20 mm lower. If you want the N1’s handling with your current position, you would add headset spacers or choose a stem with more rise. If you want a lower, more road-like position, the N1 gives it to you as standard.
Fine-tune fit with the stem, spacers and bars
Once the frame size is close, the cockpit does the rest. A longer or shorter stem moves the bars forward or back. Spacers under the stem, or a stem with more rise, raise them. Bar width, bar reach and crank length also change how the bike feels. These parts are cheap to change compared with the frame, so pick the frame for stack and reach and adjust from there.
This is how we approach fit. Our frames come in six sizes with fixed geometry, and we configure the stem, bars, cranks and gearing around each rider. Our article on custom frames vs configured fit explains when a configured bike is enough and when a rider might need something else.
Between sizes: size up or down?
Choose the smaller size if you like a lower, more aggressive position. Choose the larger size if you want a more upright position for long days. A smaller frame with a slightly longer stem usually handles more quickly. A larger frame with a shorter stem usually feels more stable.
Should your gravel bike be the same size as your road bike?
If your road bike fits well, the same frame size is usually the right starting point for gravel. Set the gravel bike up a little higher and shorter at the bars. A slightly more upright position gives you more control on loose descents and makes it easier to look up the trail. If your road bike is set up very low, don’t copy that position straight onto a gravel bike.
Get help choosing a size
If you would like a second opinion, send us your height, inseam and your current bike’s stack and reach. We’ll suggest a size and cockpit setup. Most of our customers buy without visiting, and we also offer video calls. If you are near Melbourne, you can book a workshop visit and look at the bikes in person.
Once you know your size, compare the models on our size chart or read how to choose a titanium gravel bike.
