The gears or ‘speeds’ on a bike are what allow you to maintain an even cadence and pedaling rate over varying terrain, most notably including slopes. The more speeds you have, the greater the number of sprockets and chainrings on your gearset.
The combinations of sprockets and chainrings equal the total number of speeds on a bike. What is the difference between an 18-speed and a 21-speed bike?
The main difference between an 18-speed and a 21-speed bike is the number of rear sprockets. A 21-speed bicycle has 7 sprockets, while the 18-speed only has 6 available. Although both styles have 3 chainrings in the front, the different number of sprockets is what reduces the number of available speeds you shift through by 3, one for each chainring.
To see all of my up-to-date recommendations for bikes and cycling gear, check out this resource that I made for you!
What Is The Difference Between An 18-Speed And A 21-Speed Bike
The difference between 18-speed and 21-speed bikes is the gears. However, those gears have a profound effect on how you ride.
Adding or removing a single sprocket reduces the number of speeds your bike has by the number of chainrings you have. You need more gears for a smoother ride with less muscle fatigue.
When you increase the number of speeds on a bike, you make it smoother and more effective to shift.
Smooth-shifting and larger or smaller sprockets help maintain your cadence over uneven terrain, especially up and down slopes.
Cadence, the revolutions per minute on your pedals, is the power source for a bike and affects what part of your body bears the workload and how fast you tire.
A high cadence shifts the workout to your cardiovascular system, while a low cadence makes your leg muscles work harder.
As Bike Radar says, “Experiments have shown that trying to ride faster at a lower cadence (in high/difficult gear) is more likely to lead to muscle strains and muscle soreness after a ride than achieving the same speed at a faster cadence, but with a lower load. On the other hand, too fast a cadence and you’re likely to find your pelvis rocking, lowering pedaling efficiency. You’ll also tire quickly.”
18 Speed vs 21 Speed Mountain Bike: Which Is Better
A 21-speed bike is better than an 18-speed bike. The only exception to this would be riders pedaling over flat terrain.
Without any variation on the road or trail, you wouldn’t need any gears at all. In fact, you could ride a fixie, a bike with no gears, at the same speed with roughly the same effort.
18 Speed vs 21 Speed: Which Is Cheaper
An 18-speed bike will always be the more cost-effective option. More gears cost more money because a 21-speed bicycle is a more high-end and high-performance machine.
For example, the best road and mountain bikes have 21 or more gears. It’s not merely an issue of the small amount of metal to add another sprocket, but the overall build and intended uses for the bicycle.
An 18-speed bike has 18 gear combinations. The rather uncreative name is a clear indication of the bicycle’s capabilities.
You should choose an 18-speed if you have to tackle a moderate amount of slightly rough terrain with some lower hills.
The steeper and more frequent the hills, the more you will use the gears to adjust the bicycle to maintain your cadence.
What Does 18-Speed Mean On A Bike
An 18-speed bike has eighteen gears, or more accurately, 18 possible combinations. The front chainrings comprise 3 possible positions.
Meanwhile, the back 6 sprockets are all the possible options on each of those chainrings because 6×3 = 18.
As you move your shifter, the chain will switch from one ring to the next and up and down in gear sizes to achieve each position and adjust the pedaling difficulty.
How Fast Can A 18-Speed Bike Go
An average rider can keep up a 10-15 mph pace comfortably. Bursts of faster speed approaching 20-25 is also possible for most but maintaining that pace unassisted is demanding and requires a high level of personal physical fitness.
Under particular circumstances, while drafting, downhill, or with a strong wind at your back, you can expect to go faster.
Ultimately, an 18-speed bike doesn’t go any faster than other bikes on a straight, level path. The gears (speeds) only assist you in maintaining cadence over inclines, declines, and rough ground.
Is 18 Gears Enough On A Road Bike
Using a bike with 18-gears is enough if you live and ride in areas with more level terrain.
This style of bicycle is fine at handling smaller hills and those with longer, less steep inclines. Intriguingly, what feels right to you is not what will work best for every person.
Moreover, people don’t necessarily use all the gears evenly. Low gears, the smaller ones, help you get moving from a standstill and push uphill.
The higher gears are better for descending hills and moving quickly but also harder to pedal. Stronger riders tend to use the high gears more.
How Do You Shift 18 Speed
There are different styles of shifters, from twist pieces on the handlebars to thumb switches, but they all work the same.
Shifting moves the chain from one chainring to another and from one sprocket to the next.
Below are tips for how to shift an 18-speed bike easier.
- Don’t shift too quickly. It can cause skipping.
- The right shifter is for minute adjustments, while the left will cause larger shifts. The righthand side moves the rear end of the chain, and the left moves the front, so there’s more variation but less extreme changes when you shift the back.
- As Total Women’s Cycling explains, you should avoid the extremes on the gears. “It’s tempting to stay on one chainring and just shift the gears at the back. That’s mostly fine, except for one thing. You really need to avoid using the opposite extreme ends of the gears. So, for example, don’t use the smallest cogs on the back and the front or the largest cogs on the back and the front. This pulls the chain between them at an angle, which can cause it to stretch and deform.”
- It would be best always to try to anticipate your slopes rather than shifting halfway up or down.
Best 18-Speed Bike
- Front Fork Shock
- 18 Speed Index Shifting
- Front and Rear Linear Pull Brakes
If you want to pick up the best 18-speed bike, I recommend the highly customizable Dynacraft Magna Front Shock Mountain Bike from Amazon.
This fantastic bike comes in boys, girls, men’s, and women’s sizes with 24″ and 26″ tire size choices and 4 colorways. You’ll also enjoy the convenient grip shifter and dual brakes.
The Magna is a fantastic bike for all skill levels with fast shipping, excellent customer service, and easy assembly.
Better still, the one-year manufacturer’s warranty allows you to ride worry-free.
To have this outstanding 18-speed bike delivered to your door, click here.
A 21-speed bike has three chainrings or front gears and seven gears on the back cassette.
These high-performance bicycles offer exceptionally nuanced shifting for a smoother ride. Most 21-speeds are made for serious athletes and professionals.
Choose this type of bike when you’re ready to take your existing fitness to the next level.
What Is A 21-Speed Bike Good For
A 21-speed bike is excellent for rough and hilly areas where altitude changes and slopes are common.
Many 21-speeds are ridden by experienced or professional riders. However, fit, regular riders also favor these bikes for their smooth shifting and exceptional versatility on varied terrain.
How Fast Can A 21-Speed Bike Go
A typical rider only travels around 10-15 mph most of the time.
However, professionals on 21-speed road bikes can achieve speeds of 45-55 mph in competitions like the Olympics and the Tour De France.
The top speed is usually around 110 kph or 68.3508 miles an hour.
Is 21 Gears Enough On A Road Bike
For most riders, 21-gears is more than enough on a road bike. Very few pros use 24 or more gears, and almost no riders truly use all their gears.
Instead, most play to their strengths and comfort zone, which is what you’re supposed to do.
Moreover, you technically don’t need all the gears on a 21-speed for riding because some are more about smooth-shifting.
As a contributor explains on Bicycles Stack Exchange, “…some of the gear combinations overlap (or near enough), and this means you don’t really get any extra function from them, but having them can make gear changing up/down a range smoother because it means you have to change the front sprocket less often. The exact number of “useful” gears will change based on the number of teeth you have in your particular setup, but the principle is the same.”
Best 21-Speed Bike
- SHIMANO 21 SPEED Shifting system ensure you to brakes for safety at any speed
- DISC BRAKE Bicycle provided great stopping power.
- 3 SPOKE 700C MAG WHEEL Bicycles for Men and Women 5’8”-6’1” Group
- 700C x28C professional Racing bike tire can make your cycling more easy
- Free pedals and comfortable seat include in the packages.
The best 21-speed bike is the Eurobike EURXC550 Road Bike from Amazon. This incredible high-performance bicycle has 700c Mag wheels and dual disc brakes.
The high-carbon steel frame is incredibly durable and won’t weigh you down at just 36.4 pounds.
Meanwhile, a curved professional handlebar gives outstanding control and is well-suited to experienced riders.
With front and rear Shimano derailleurs and a Shimano shifter, you can rely on the smooth gear transitions.
Eurobike has US warehouses in Califonia and New Jersey for fast delivery to any address.
To learn more about this exceptional bicycle, click here.
Helpful Tips To Know About 18-Speed vs 21 Speed Bikes
Beginners and intermediate cyclists are usually content with the performance and versatility of an 18-speed bike.
However, those seeking to push their riding to the next level should look into a 21-speed.
Here are a few more helpful tips to know about 18-speed vs 21-speed bikes.
- Chainrings are merely the name given to front gears or sprockets. These will have teeth that settle into the chain and move the wheels like the rear gears.
- The number of ‘speeds’ on a bicycle is a misnomer. You cannot necessarily go faster with more speeds, but it makes things easier when ascending or descending steeper roads and trails.
- The average rider will be pleased with the variety of gears on an 18-speed bike. However, 21-speeds are becoming more common and are in high demand.
A 21-speed bike will be smoother and easier to ride over varied terrain than an 18-speed bike.
However, with that convenience comes a higher price tag. Moreover, an 18-speed is sufficient for numerous landscapes, even when it’s hilly or rough.
Having just one more sprocket to combine with your chainrings can make a world of difference.
It is essential to maintain your cadence as you ride because it helps prevent muscle fatigue, and more speeds equal better cadence control on slopes.
Only you can decide how many gears you need, but now you can easily make an informed decision.