Mountain Bike Gears Explained

Mountain bike gears are continually becoming more and more complicated and intricate. Today’s bikes can come with up to 27 gear ratios. It is common for a mountain bike today to use nine gears in the back and three sprockets of different sizes in the front for gear ration production.

Why so many gears? The most common reason is that a large number of gears allow a rider to pedal at the same pace no matter what terrain that he/she is on. This can be understood better if you think about a bike that just has one gear. Every time you turn the pedals one full turn, then the rear wheel also turns one full turn, too (1:1 gear ratio).

For example, your back wheel is measured at 26 inches. If you pedal one full turn, then this would mean that your wheel moved 81.6 inches. If you are riding at 50 RPM, then you will be able to go 340 feet per minute. This means that you were going 3.8MPH, which is equivalent to walking speed. This speed is great for going up a hill that is steep, but it is not a good speed for flat ground or racing downhill.

If you want your bike to go quicker, then you will need a different ratio. If you want to reach a speed of 25 MPH downhill using a 50-RPM cadence, then you will need to have a 5.6:1 gear ration. If you have lots of gears on your bike, then you will be able to get that ratio so that you can continue your pedaling at a consistent pace, no matter what terrain you are on or what your speed is.

A typical mountain bike that has 27 gears will have six gears so incrementally close to the other that you will not be able to determine that there is any difference between the gears when you change them.

Most mountain bike riders decide to choose a gear system with a front socket that is suitable for the slope or terrain that they usually ride on and they stay with this choice, even though it may be more difficult under a heavy load to shift the gears. This is purely a personal decision, but it is simpler to shift between gears when the rear socket, rather than the front one.

When you are pedaling uphill, then you will find that it is much better to choose a sprocket that is smaller on the front and then shift gears with the nine gears that are available on the rear. If you are more speeds on the rear sprocket, then you will find that it is much more efficient to ride.

Mountain biking needs gears so that you can keep an overall speed going. If you didn’t have gears, then you would find it difficult to build up any speed and you would find it nearly impossible to pound your pedals for extra control. Gears help to move the pedals and enable you to gain that speed.