How fast can an 18 speed bike go?

Have you ever wondered how fast an 18-speed bike can go? Let’s take a deeper look based on different bike types and fitness levels.

How fast can an 18-speed bike go?

An 18-speed bike can go as fast as 35mph. But that requires a good rider and a light bike with good gear ranges. The better question to ask would be: How fast can YOU go on an 18-speed bike?

How fast can you go on an 18-speed bike?

Your speed on this type of bicycle depends on two things:

Your fitness level and your bike.

The determining factor is probably about 75% your fitness and 25% your bike choice.

Because the sad truth is this:

Yes, you will be faster on a 30-speed, top-of-the-line road bike than on a basic 18-speed mountain bike. Especially over long distances and on paved roads.

But a Tour de France rider on an 18-speed mountain bike will still be faster than you if you ride that pure-bred 30-speed racer. Probably in both sprints and long distances.

The rider is just the bigger factor in all of this.

So let’s take a closer look at what speeds you can expect, based on your fitness level first.

We will then look at what difference the bike makes and how uphill / downhill affects your speed.

What is the top speed of an 18-speed bike?

Let’s assume that we are talking about a regular (hybrid) 18-speed bike for this.

The average rider can expect to top out around 35mph on a good bike.

A rider who is in better shape may be able to push it past the 42mph mark.

Keep in mind, that this is not a modern road bike purpose-built for racing.

Road bikes usually come with more gears and allow you to maintain higher speeds for longer.

What is the average speed of an 18-speed bike?

Again, this is more about the rider than the bike.

Most beginners may average around 8-14 mph (12-23km/h).

An average rider may average about 17-22 mph (27-35km/h).

A trained (and fit!) rider may average as much as 27mph or more (43km/h) over a long distance.

What difference do bicycle types make

Now let’s see how different types of 18-speed bikes compare.

We will only look at the Average Rider from the table above.

As you can see, upgrading your bike will make you faster.

But it will rarely ever be faster than a fitter rider.

How fast can it go downhill?

To go truly fast, it helps to go downhill.

But the bike’s downhill speed is not as dependent on the number of speeds.

Rather, it is often limited by the highest gear range.

So a single-speed bike can be just as fast as a 30-speed bike.

The bigger question is: How steep is that hill and how long can you roll for?

If you have a big enough hill, an 18-speed bike can realistically reach over 60mph (100km/h).

But if that’s safe is up to the rider to decide.

If you want to attempt to test this, make sure to have proper disk brakes on your bike. A rim brake is just too dangerous for these speeds.

If you want to know more, be sure to also check out my article that answers the question How fast can a bicycle go downhill in more detail.

Gear ranges for downhill sprints

There are generally 2 types of 18-speed setups: 3×6 or 2×9. Both have unique pros and cons to them.

The 3×6 drivetrain

The 3×6 drivetrain has 3 chainrings in the front and 6 cogs in the rear. This setup is often found in budget or older 18-speed bikes.

The advantage is that it gives you 1 chainring for climbs and acceleration, 1 cog for everyday cruising, and one cog for downhill and top speeds.

The disadvantage is that it may have redundant gear ratios that don’t give you 18 unique speeds.

Some of the front-and-rear combinations can become quite similar.

The 2×9 drivetrain

The 2×9 drivetrains have only 2 chainrings in the front, but 9 cogs in the back. This setup can be found in vintage or very modern bikes.

That setup gives you one cog for acceleration and climbs and one cog for downhill and top-speeds.

The advantage is that it generally has less redundant speeds and a wider range of gears. So the difference between the first and the 18th gear is usually much greater than with a 3×6 drivetrain.

The disadvantage is that sometimes the steps between the gears can be a little bigger than for a 3×6 drivetrain. An experienced rider will not be bothered by it, but it can be a challenge for a new rider.

How fast can it go uphill?

How fast an 18-speed bike can go uphill depends on the hill and the lowest gear ratios of the bike.

The steeper the climb, the slower the bike.

If it is really steep, it may even be too steep to ride uphill at all.

As a general rule of thumb, the only gears that matter, in this case, are the low gears, or even ultra-low gears.

Those are the biggest cogs on your rear wheel combined with the lowest front chainring.

The bigger the largest rear cog and the smaller the front chainring, the slower (and more effortlessly) your bike will be able to crawl up the hill.

So the answer is, probably anywhere between 1mph and 25mph for the average rider.

Are 18-speed bikes fast?

Now you have seen how fast 18-speed bikes can be. You also know how to make them even faster.

But are they fast compared to other bikes?

Let’s summarize:

• For most people, 18-speed bikes are fast enough.
• 18-speed bikes are great for the everyday rider. They have enough gears for acceleration, top speed, as well as trails with uphill and downhill sections.
• Remember that you are limited to 18 steps to get from the slowest to the fastest gear ratio – you are not limited in speed itself.

If you are looking for a fast bike, you may want to upgrade to a road bike.

Compared to a 21-speed bike, however, some 18-speed bikes may even be a tad faster.

How about a real-life test?

If you’re interested in seeing a real-life test on bike speeds, check out my article How fast can a 7-speed bike go? (Faster than you may think).

In it, I took my humble 7-speed hybrid bike for a spin and went as fast as I could. The results truly surprised me and inspired the first post in this series.