A gear ratio is how many times the rear wheel turns in one rotation of the cranks.
How to Calculate Gear Ratios on a Bike
Figuring out gear ratios on a bike is pretty easy. All you need to do is divide the number of teeth on the front chainring by the number of teeth on the rear cog. This helps you know how many times the rear wheel spins with each pedal stroke. The formula is:
Gear ratio = Number of teeth on front chainring ÷ Number of teeth on rear cog
For example, if you’ve got a front chainring with 40 teeth and a rear cog with 16 teeth, the math would look like this:
Gear ratio = 40 ÷ 16 = 2.5
So, for every pedal turn, your back wheel spins 2.5 times. Knowing this ratio can help you pick the right gear for your ride, whether you’re speeding down a flat road or grinding up a steep hill. It’s also a handy way to make sure you’re getting the most out of each pedal stroke.
Best Gear Ratios for Different Terrains
When it comes to choosing gear ratios, it depends on the terrain and your riding style. For flat roads, a ratio between 2.0 and 3.0 is usually great because it gives you speed without too much effort. On hilly routes, something between 1.0 and 2.0 makes climbing easier and helps with control on the downhill. For off-road trails, a ratio in the range of 0.7 to 1.5 works well, especially for tricky spots or steep climbs. These are just general ideas, though—don’t be afraid to experiment and see what feels right for you! In the end, it’s all about what feels comfortable for your body and the type of ride you’re tackling.
Single-Speed or Multi-Gear Bikes?
If you’re riding a single-speed bike, the gear ratio is a big deal since you only have one option! You’ll want to choose something that fits your regular terrain, like your daily commute. But if your bike has gears, like most road or city bikes, ratios still matter. They’ll help you figure out the best gear for cruising or for switching when you hit a tough hill.
