Written By: Jonathan
Fact Checked By: Caroline Dezendorf
Reviewed By: Matt Tanner
If it happens to you that while cycling, at one moment you feel very relaxed, but at the next moment it feels like you are doing some exercise, then you are not alone in this situation.
The real reason why this happens is because of bicycle gears, as they are the key to making your ride more smooth, no matter whether you are climbing a hill or traveling on a flat road.
So understanding how gears work is not just for bicycle mechanics or professionals, but it is simple and essential for everyone to learn which can literally make a huge difference in how comfortable and efficient your ride is.
In this guide, you will learn how do bicycle gears work and what each part does, and most importantly, how to use them correctly, even if you’re a real beginner in the world of cycling.
What Are Bicycle Gears?
Bicycle gears are a part of the drivetrain system of a bicycle that actually helps control how hard or easy it is to ride.
Yes, it also depends on where and how you’re cycling, but in simple terms, gears allow you to adjust the resistance of the cycle: just like changing the settings on a treadmill or exercise cycle.
So, when you change gears, the chain moves between differently sized sprockets, called chain rings on the front and cogs on the rear cassette.
And this literally changes the gear ratio, which affects how often your wheels turn compared to how often you pedal.
Plus, the main purpose of bicycle gears is to help you maintain a really comfortable pedaling rhythm called “cadence”.
Plus, it doesn’t matter whether you’re climbing a hill or riding on flat ground or going downhill.
Low Gear: If you set them in a low gear, with a smaller chainring on the front and a larger cog on the rear, you’ll find that pedaling is easier but the going speed is slower, which is actually ideal for climbing.
High Gears: In high gears, where the front chainring is larger and the rear cog is smaller, it will be harder to pedal, but you’ll find that each push will take you farther, and this is great when you want to increase your cycling speed on flat or downhill terrain.
This is why gears must act like mechanical leverage: because they allow you to exchange force for speed or vice versa, so yes this also depends entirely on the situation.
Because without gears, you’d either struggle uphill or lose control going downhill, which is why even simple bikes nowadays come with multiple speeds, from 7 to 30 or more, so you can always find the perfect balance of power and efficiency.
Main Components of a Bicycle Gearing System
There are several key parts are available on the bicycle’s gearing system, as they work together to control how power form your pedaling turn into motion.
1. Chain
At the heart of this system is the chain, a strong metal loop that actually transfers the energy from the pedals to the rear wheel.
Depending on your convenience, the chain moves between different sized gears, making the ride easier or more difficult, depending on the terrain.
2. Front Chainrings/Crankset
Now, at the front of the bicycle, to the connected to the pedals there are the front chainrings are available which is also known as the crankset.
These are the big round gears that you see near your feet, and mostly bicycle comes with 1 to 3 of them.
3. Rear Cassette/Freewheel
At the back of the wheel you will find the rear cassette and on older bicycles this is called a freewheel, which is a set of small gears that when shifted move the chain.
And the simple fact is, the more gears you have on the cassette, the more precisely you can adjust your effort and speed.
4. Derailleurs (Front & Rear)
The derailleurs are responsible for moving the chain between these gears, and are installed one at the front and one at the rear.
These are spring-loaded mechanisms that physically guide the chain from one gear to the next when you change gears.
5. Shifters (Grip Shift, Trigger Shift & Integrated Shift)
Now finally, there are the shifters which are located on the handlebars and their job is to control the system.
There are different types of shifters available such as:
- Grip shifters that change gears by twisting.
- Trigger shifters require you to press a lever to change gears.
- Integrated shifters which are often found on road bicycles.
So together, all of these components form a complete and responsive system that enables you to adapt to hills, headwinds and speed with a simple flick or twist of your fingers.
Types of Bicycle Gears
Different types of bicycles come with different types of gear systems, as each is designed for specific riding styles and environments.
If we understand these types of bicycle gear it can really help you in choosing the right bicycle for your needs or in better maintaining the bicycle you already have.
1. Derailleur Gears
You’ll find these types of gears on road bikes, mountain bikes, and many hybrid models, making them the most common type of gear on bicycles.
A derailleur system is used to run the chain between multiple sprockets on the front crankset and rear cassette, the exposed mechanisms being called front and rear derailleurs.
Not only that, this system actually allows for a wide range of gears, often ranging from 7 to 30 speeds.
| Pros | Cons |
|---|---|
| Really light and efficient. | It requires regular cleaning and adjustment. |
| Offers a virtually huge variety of gear combinations. |
2. Hub Gears
You can see hub gears on commuter bicycles, city bicycles, and some touring bicycles. Unlike derailleur systems, hub gears are completely enclosed inside the rear wheel hub.
With hub gears riders can choose from literally 3 to 14 gear options, yes it depends on the model.
| Pros | Cons |
|---|---|
| Because the gears are sealed and protected from dirt and all weather, it is low maintenance. | It is heavier than the derailleur system. |
| You can change gears even while in a stationary position. | Slightly less efficient for racing. |
3. Single-Speed Bikes
So single speed bicycles do not have any gear changing system as they only use one gear ratio, making them really simple to operate and maintain.
Moreover, these bicycles are very popular for short trips, casual travel, and flat lands.
| Pros | Cons |
|---|---|
| It is a low-maintenance and budget-friendly bicycle. | Not for climbing the mountain. |
| Ideal for urban environments. |
4. Internal Gearboxes
Yes, this is completely very rear and some high-end bicycles, including some electric bikes and premium touring bicycles, use this internal gearbox built into the frame or crank area.
This system provides virtually smooth, reliable shifting and is completely enclosed which protects them from any kind of wear and tear.
| Pros | Cons |
|---|---|
| Very clean look. | Expensive and heavy. |
| Extremely durable and provide consistent performance. | Greater complexity in repair or replacement of any part. |
| Gear Type | Common Use | Gear Range | Maintenance | Can Shift While Stopped? | Pros | Cons |
|---|---|---|---|---|---|---|
| Derailleur Gears | Road bikes, mountain bikes | Wide (7–30+ speeds) | Medium to high | ❌ No | Lightweight, efficient, lots of gear options | Exposed parts, requires regular cleaning and tuning |
| Hub Gears | Commuter, city, touring bikes | Moderate (3–14 speeds) | Low | ✅ Yes | Sealed system, low maintenance, can be moved when stopped | Heavy, fewer gear options, difficult to repair |
| Single-Speed Bikes | Urban, casual, short distances | None (1 speed only) | Very low | ✅ Yes (no shifting) | Simple, inexpensive, minimal maintenance | Not suitable for hills or long distance riding |
| Internal Gearbox | High-end, touring, e-bikes | Wide (varies by model) | Very low | ✅ Yes | Enclosed, Neat look, Durable | Expensive, complicated to repair or replace |
How Do Bicycle Gears Work?
Bicycle gears actually work by moving the chain between different sized gears making it easier or harder to pedal depending entirely on the terrain.
Whenever you want to change gears, the front derailleur or rear derailleur physically guides the chain from one chainring or cog to the next.
Relationship Between Front Chainrings & Rear Cassette Cogs
The front chain ring, located near the pedals, and the rear cassette cog, located behind the wheel, actually work together to create different gear ratios.
And a lower gear means a smaller chainring on the front and a larger cog on the rear, which really makes pedaling easier, as the wheel spins less with each pedal stroke, making it ideal for climbing hills or riding smoothly in strong winds.
High gear: This uses a larger chainring on the front and a smaller cog on the rear which gives the wheels more spin with each pedal turn and is perfect for riding fast on flat ground or going downhill, but yes, it does indeed require more leg power.
Go Up or Down
When riders say they are “Going Up Gear” they mean going to a harder gear/higher gear and this does indeed increase speed but requires more effort.
“Going Down Gear” means going to an easier gear/lower gear, which reduces resistance and helps during difficult climbs or starts.
The purpose of any type of gear combination is to keep the bicycle at a steady, comfortable pedaling rhythm, called cadence, and by selecting the right gear for that particular situation, you can easily achieve what you want.
It doesn’t matter if you’re running at high speed, climbing a steep slope or climbing a hill, simply changing gears helps you stay efficient and always in control.
Gear Ratios Explained
The gear ratio in cycling actually tells you how many times the rear wheel turns for each complete revolution of the pedals.
Additionally, it is calculated by dividing the number of teeth on the front chainring by the number of teeth on the rear cog.
For example, if your front chainring has 48 teeth and the rear cog has 16 teeth it means your gear ratio is 48 ÷ 16 = 3.0 and that means for every full pedal rotation, your rear wheel will rotate three times.
Why it’s Important
Then what is its significance?
This is important because the gear ratio directly affects how hard or easy it feels to pedal.
- Low gear ratio: Such as 1.0 or 1.5, this means it will be easier to pedal but will travel a shorter distance per pedal stroke and is great for climbing hills.
- High gear ratios: Such as 3.0 or higher, make it harder to pedal but allow more speed, which is ideal for driving really fast on flat roads or downhills.
So using the right gear ratio will definitely help you maintain a steady pedaling rhythm known as cadence, and this is very important for both comfort and efficiency.
So, if your gear is too stiff your legs will tire quickly and if it’s too easy you might move around quickly but won’t get anywhere.
| Front Chainring (Teeth) | Rear Cog (Teeth) | Gear Ratio | Pedaling Effort | Best For |
|---|---|---|---|---|
| 34T | 28T | 1.21 | Very Easy | It is ideal for steep hill climbs, great for beginners. |
| 42T | 28T | 1.50 | Easy | It is used for hill climbing and comfortable riding. |
| 50T | 25T | 2.00 | Moderate | It is great for city commutes as well as moderate terrains. |
| 52T | 18T | 2.89 | Harder | You need to use it on flat roads, driving at high speed. |
| 52T | 13T | 4.00 | Very Hard | For sprinting, downhill, racing you have to use that combination. |
How to Use Gears Effectively
If you really wanted to make your ride smoother, easier and more efficient, then you have to know how to use a bicycle gears effective.
The most important rule is to shift gears before the terrain changes, not during the terrain.
For an example, if you see a hill coming then you have to shift to a lower gear before you start climbing actually, it also prevents the chain from slipping.
As it keeps the chain moving smoothly and prevents putting too much pressure on your bicycle.
So, basic rule is to avoid shifting under heavy load such as when you are standing up and pedaling hard because it can literally cause the chain to slip or damage the drivetrain badly.
Conclusion
So, this is very essential knowledge for anyone who wanted to ride with more efficiently and comfortably bicycle.
As gears actually helps you to tackle hills, maintain a steady rhythm and ride longer with less fatigue, so by learning the parts of a gear system and the different types available and how to shift properly, you can actually make smarter decision on the road or trail.
So, mastering your bicycle’s gearing system actually allows you to ride smoother, safer and with more control manner.
I am sure with this complete guide on How Do Bicycle Gears Work?, you have leveled up your knowledge and become more confident with your gears.
FAQ’s on How Do Bicycle Gears Work?
Q1. What gear should I use when going uphill?
Answer: You have to use a low gear, it literally means you have to shift to a smaller front chainring and larger rear cog, that makes it pedaling easier so you can easily climb without overstraining your legs.
Q2. Do you shift gears while pedaling?
Answer: Yes you can, as the best practice for proper technique is to slightly reduce pedal pressure when changing gears, then you can return to your normal speed after the gear change.
Q3. How do I know when to shift gears?
Answer: You have to change gears just before a hill or terrain change, so avoid changing gears when you are pedaling very fast, so slow down the gears a little to keep the chain running smoothly.
References
- For a mathematical analysis of gear performance and drag effects, see Larson’s (2019) study on Bicycle speed through different gears with drag.
Jonathan, the passionate owner of Bicycle Time, brings a lifelong love for bikes and automotive craftsmanship, that reflects into every corner of the shop. With deep passion in both cycling and automotive accessories, Jonathan is more than just an expert.