What is the meaning of a 21-speed gear bicycle or mountain bike?

Bicycle gears for beginners

Bikes can be troublesome to pedal especially if you encounter different terrains. It is for these reasons that gears were invented. Just like those of a vehicle, gears are supposed to make it easier to get the load over terrain and in this case, you. Bikes without gears will need extra effort and sometimes stall when the hills are too steep. The effect is the same on steep hills. Bikes such as the fixed gear ones will not only be hard to pedal but will be a risky affair for the rider. Gears are designed to keep the cadence as consistent as possible no matter the terrain. Cadence is the number of revolutions that your feet are making per minute. This should remain between 75 to 90 revolutions every minute no matter the terrain. Gears not only allow to you scale different terrain but help you achieve high speeds. There are different gear speeds all of which are disposed to different results.

The different gear speeds

Bikes will range from 1 speed all the way to 27. Riding a bike with multiple gears is not as easy since you will need to learn how to combine the gears for them to work. Different gears will provide different possibilities when it comes to handling the terrain. This doesn’t, however, mean that bikes with more gears will outperform those with 21 gears. The best combinations are what makes the difference when it comes to riding gear bikes.

➥ Here, you can also get the idea of Fixed gear vs. Single speed bike.

21-speed bike gears explained

Bikes will come with front and rear end gears all of which are fixed onto cogs. The front cogs in most instances will range from 1 to 3. The rear cog will hold some cogs which are where the spokes that hold the chains rest ranging from 1 to 9 of them. Gears are calculated with the combinations that they can make. The gears are shifted using a lever mechanism on the handlebars. The mechanism is often manual, but there are instances in high-end bikes where it is electrical.

The front end and back end cogs are joined to each other by a chain that runs through a derailleur. The work of a derailleur is to move the chain from one cog to another. The derailleur shifts the tension of the chain allowing it to move higher on the cogs or lower depending on the combinations set by the rider. There is a tension cable connecting the gear shift levers to the derailleur.

The front gears are handled by one side of the handlebar while the other is handled by the opposite side. This may take more time to master but is not impossible to control eventually.

The number 21 comes from the combinations of the gears. Three front cogs can work with seven gears to provide 21 combinations that the rider can use. A bike with nine rear cogs will combine with three front to make sure that to provide a 27-gear setup.

How to use the gears

It is almost impossible in most situations to use all the gears. The best way to learn about the utilization of the gears is while riding. The gears will respond to a shift in the gear levers. It is advised that you keep the front cassette to the medium one while changing the rear cogs up and down to get the effect of the change. A slight change in gears will make a difference. It is also advised that you do not work with the extremes. Using either large cogs or both small ones will increase tension in the chain leading to an imminent breakdown. Only shift up and down using the medium cog on different terrain to get aa feel of how the bike will respond.

How fast can a 21-speed bike go?

The rate of a 21-gear bike will be determined by some issues. All these make it impossible to pinpoint the real speed of a 21-gear bike. There have been extremes with most people saying that they have done 20 to 31 mph. There have been however reported cases of people doing 60 mph or more downhill. The speed of the bike will be determined by how fast you can pedal as well as the condition of the bike. The type of bike will also go a long way to contributing to this. Pro bikes are known to be fast, and so it is possible that a fit pro could hit very high speeds on a bike.

Gear shifting tips for beginners

• Gears are delicate when it comes to variations. It is, therefore, wise that you know the limits of your gears.
• Ensure that you lubricate your gears often enough so as to keep them from wearing out. The whole drive train needs to be lubricated so as to make sure that the chain is not strained in any way.
• Take time to get rid of any rust on the chain especially if the bike has been in storage for a long time. Cleaning this with lime will help before greasing again.
• Shift the gears before hitting a different terrain. Doing this after you have started riding on a hilly will stall the bike eventually. Doing this gradually also allows your feet to adjust to the new terrain ensuring that you do not get overtired.
• Do not shift gears to extremes as you will risk breaking your chain. Your bike will also experience difficulties moving at this point.

It is wise to note that even pro riders will not use all the gears on the bike.  Most will often use about 7 gear combinations at most. Taking time to learn the capabilities of your 21-speed bike will help you ride even in the most challenging of situations. You also need to remember that more gears will not necessarily mean more speed. You will however definitely enjoy more comfort while pedalling on treacherous terrain.