Superficially, mountain bike gears can seem easier to understand than their road bike gear counterparts. At least on high end mountain bikes that have a 1X drivetrain. You just switch the lever one way to go faster or switch the other way to lessen the load on pedaling. What’s hard, though, is choosing the right gears to be in on your bike. Choosing the right gear will improve your biking experience and we teach you everything in this guide to biking gears explained.
Most people do not bother changing the gears that came with their bikes, but if you would like to swap out for a gear ratio that suits your rides better, you might end up being confused and even make things more difficult for yourself.
The fact is that the gear ratios for hilly cycling are not the same as those you need for city riding. To help make things easier for you, we have a complete guide to road bike gears and mountain biking gears.
Bike Gears Explained
There are two main sets of gears on a mountain bike or road bike; front gears and rear gears. For many mountain bikes there is only one front gear, while road bikes will come with multiple gears on both the front and rear.
Front Bike Gears
Also called chainrings or a crankset, the ‘front gears’ as called by less jargon-savvy cyclists are easier to understand. The whole assembly of the crank arms and the front gears is actually called the crankset or sometimes a chain-set. Most mountain bike cranksets’ have double (2X) chainrings. High end mountain bike gears on the other hand have 1X chainrings. They are becoming popular but are still not common.
The smallest chainring on the crankset is always the one closest to the frame, and when the chain is on this ring, you will find it easier to pedal. Consider this your pedaling uphill gear. As you move the chain away from the frame, the pedaling gets harder, but the speed increases. For a 2X chainring, the bike is said to have inner and outer gear, while for the 3X chainring, there is an outer gear, middle gear, and granny gear.
Rear Bike Gears
Also called cogs, the gears on the rear wheel, when put together in ascending sizes, are referred to as a cassette. Most bikes have 8-11 cogs in their cassette, with the largest gear being closest to the wheel. The gears are numbered from the inside out.
As opposed to the front gears, whereby the larger the chainring the harder it is to pedal, for the rear gears, the larger the cog, the lower the gear, and thus the easier it is to pedal, which means you will move slower, but have less resistance in your pedal.
How Do You Know the Number of Gears In a Bike?
The ‘hyping department’ always likes to multiply the number of chainrings by the number of cogs, and this brings about a large number, and this makes selling bikes easier- you know big numbers are impressive. A 3×8 gear ratio has three on the front and eight on the rear. You will hear this called a 24 speed bike. The problem with this is most bikes cannot actually operate efficiently in all 24 gears.
You see, being in the first gear on the front, and the eight gear on the rear for a 2×8 bike can create chain cross. You don’t want your chain to be sitting diagonally across the front crankset and rear cassette.
When we talk about the number of gears a bike has, which essentially dictates its top speed, we refer to the number of cogs. An 8 speed or a 9 speed. Veteran bike riders will also term bike speed in terms of 1×12 or 2X9 or any other variation.
Biking Gears Explained – Shifting
While practically speaking you just need to click the shifter when shifting gears. However, there are a few good techniques you should follow. These tips will help reduce the wear and tear of the chain and reduce the chances of experiencing dropped chains.
When you feel the pedaling is getting too easy or too hard, you know it’s time to shift gears. To do that;
- Slightly ease up your pedaling speed
- Click your shifter once to make a gear change
- Continue to pedal until the chain settles on the gear you just shifted. Do not accelerate or push extra hard while the chain is transiting to the next gear
- There may be a clicking sound when the chain is transitioning to the new gear. Once done, you will feel the smoothness in your rides, and the chain will move quietly.
Gear Shift Setups on Most Bikes
- In most cases, the left shifter controls the front gears. Use it when you want to alter speeds fast. The jump in resistance is much greater when changing the front gear.
- The right shifter controls the rear gears. Use it to make small changes to your speeds
- With road bike gears on a drop handlebar you press the lever closest to your thumb on the right shifter inwards when you want to ride on lower gears. The second lever is pulled inwards whenever you want to ride on higher gears. For mountain bike gears they are usually changed with a thumb lever on a flat bar handlebar.
More Biking Gears Explained
- Always anticipate when gear shifting is necessary so that you can get to a proper gear before needing it. For instance, when making sharp turns, you need to downshift into low gears. Therefore, as you approach sharp corners, accelerate down to pace down. The same goes for hilly rides. Ensure to switch to low gears before hitting an incline
- Use the rear gears to make small adjustments to your speed and the front gears to make big adjustment to your speeds
- Avoid adjusting your rear and front gears simultaneously. You should shift one and then the other, but avoid doing it simultaneously. For people with one front chainring, this will not be a concern
- Avoid creating large chain angles whereby you use the largest front and the smallest rear cog. This normally creates more stress on the chain and is often the main reason for dropped chains. Instead, we would recommend that you use intermediate gear combinations to get a similar gear ratio
- When riding uphill or against the wind, use the small front chainring or middle front gears and bigger rear cogs. When going downhill, use the biggest front chainring and smaller rear cogs. On flat terrain, use the big or middle front gears and a range of rear cogs
Biking Gears Summary Explanation
We do hope that our biking gears explained guide has taught you a thing or two about gears, including how to shift gears and knowing the right gear to buy for your rides.
Just to recap on the shifting aspect;
- To shift the front gears, use the left shifter
- To shift the rear gears, use the right shifter
- For smooth shifting, pedal steadily while shifting one gear at a time. Don’t back-pedal when shifting gear
- If you are pedaling too fast, it means there is not enough resistance. Therefore, shift to a harder gear, and this will help you go fast
- If you are pedaling too slowly, it means you are in the wrong gear. Shift to an easier gear to go at a more efficient rhythm
- Moving the chain closer to the bikes means easier pedaling but slow speed and vice versa
To master gear shifting, you need to practice. With time, you will be shifting like a pro. Happy riding! Once you have shifting figured out, read up on these cool mountain bike accessories so you can ride in style.