Mad Duck Cyclery / Road + gravel
Climb with room to spare. Settle into your rhythm. See what each gear means for your speed before you change a single part.
Use Gear Lab belowFree interactive calculator · Use it right on this page
Try it here
Choose your drivetrain and tire size, set your cadence, then click a gear to compare speeds. Scroll inside the calculator to see the full gear chart.
Prefer a larger workspace? Open the calculator in a separate tab ↗.
What Gear Lab does
Gear Lab shows the speed that matches your cadence, gearing and tire size. Compare front chainrings, click through a cassette, and see how much each shift changes your speed at the same pedaling rhythm. The best setup is the one that gives you usable gears for the riding you actually do.
A smaller front chainring or a larger rear sprocket gives a lower gear. Look for a combination that lets you keep turning the pedals at the slower speeds you encounter on steep climbs, loose gravel or tired legs.
Start with the cadence you naturally enjoy. Check which gears put you near your usual riding speed, then compare the gaps between them. Smaller gear steps can make it easier to fine-tune your cadence.
A larger front chainring or a smaller rear sprocket gives more speed at the same cadence. Check whether you need that extra high gear—and what you would give up at the climbing end.
A quick start
Understanding the tradeoff
A cassette’s range tells you how far apart its easiest and hardest gears are. Gear spacing tells you how big each shift feels. A wide range can help cover steep climbs and fast sections, while closer steps can make it easier to hold a preferred cadence.
A 1× drivetrain has one front chainring. Making that ring smaller lowers every gear; making it larger raises every gear. A 2× setup gives you two front rings to work with, with some overlapping ratios.
With the same cassette, tire and cadence, a 44T ring gives 10% more speed than a 40T ring in every rear gear. It also makes the lowest gear 10% taller—so climbing at the same road speed requires a lower cadence.
Choose for your route
| Your riding | Start here | Then check |
|---|---|---|
| Rolling roads & group rides | The gears around your usual cruising speed. | Are the shifts small enough to keep a comfortable cadence? |
| Steep climbs & long days | Your smallest front ring and largest rear sprocket. | Does the lower gearing suit the slow climbing speeds you expect late in a ride? |
| Gravel & mixed terrain | The low end of a wide-range cassette or XPLR setup. | Does your chosen 1× ring also provide the top-end gearing you want? |
| Fast flats & descents | Your largest front ring and smallest rear sprocket. | Can you use that gear at your actual speed and cadence without sacrificing the low gears you need? |
Gear Lab compares gearing; it does not automatically choose a “best” setup. Your terrain, fitness, riding load and cadence preferences all matter.
The result shows speed for the selected cadence and gear, assuming no wheel slip. Wind, gradient and rolling resistance determine how much effort that speed takes.
A larger wheel circumference covers more ground per revolution. Tire-size estimates are approximate: rim width, pressure and load affect the real measurement. Use measured rollout for the closest comparison.
A ratio that works in the calculator may not fit your bike. Cassette speed, derailleur capacity, freehub, chain, chainline and frame clearance must be compatible. Crank length itself does not change the speed at a given cadence and gear ratio.
The Mad Duck take
Start with a low gear you can turn comfortably when the ride gets hard. Then check your everyday cadence and the top-end speed you need. Bring us the combinations you are comparing—we can help translate the numbers into a compatible setup.