If you’ve ever used a mountain bike on the road, you’ll know that their big knobby tires tend to be super slow on pavement. As a result, you may have wondered:
Can You Put Road Bike Tires on a Mountain Bike?
You can usually put new tires on a mountain bike that have a better tread pattern for road cycling. However, you can’t simply take a tire off of a road bike and install it on a mountain bike, without verifying that it fits properly. In particular, the diameter and width of a tire must be compatible with your wheel.
That’s the high-level view, but before you head to the bike shop, there’s a few more things you’ll probably want to know. Here’s what we’ll cover next:
How to Find Different Tires that Fit Your Mountain Bike
Finding the right tire fit for your mountain bike may seem a bit complicated. But at the end of the day, there are just a few key pieces of information you need to make sure you understand.
Specifically, you’ll want to know the following:
- Tire diameter
- Tire width
- Type of tube valve
- Tread pattern
Let’s look at each of these in detail below.
Tire Diameter
To know what tire diameter dimensions to go for, check the sidewall of your tire. That is where most brands indicate the diameter and width of the tire.
For example, here are the numbers displayed on the side of my mountain bike’s tire (I know, it’s pretty worn down):
If you can’t quite make out the numbers, it says 26 x 1.75.
That means that my bike takes a tire that has an outer diameter of 26 inches, and a width of 1.75 inches.
When it comes to the diameter of the tire, there’s basically no compromise. You need a tire that is going to exactly match your wheel. And probably the easiest way to find the diameter you need, is just by reading the numbers off of your current tire (like shown above).
With that said, you’ll probably also find it useful to know that there are a few different WAYS these numbers might be displayed on a given tire.
The above number system is pretty common for mountain bikes, but road bikes often use a different number system. For example, my sister’s road bike tires look like this:
Her tire shows a size of “700 x 25”.
You might be thinking “700 inches is WAY too big for a bike tire!”
And you’d be right, these measurements for road bikes usually use the metric system. So, what it really means is that the tire has a 700 millimeter outer diameter and a 25 millimeter width.
Much more realistic than a tire that would nearly span the length of a bowling lane.
These two measurement systems that I’ve shown you are probably the most common numbers that you’ll see on the side of bike tires. But they are not the only ones, so if you are having a hard time finding your size, then it might be best to double check with an expert at a local bike shop.
Now, there are a couple more things we need to cover when it comes the width of a tire.
Tire Width
We already mentioned that you need to match the diameter of your tire precisely, and generally, it’s probably easiest to get the right fit if you do the same with the tire width.
With that said, if you’re really looking to customize your ride, you may have a little wiggle room to adjust the width of the tire you use.
And why would you want to do that?
Well, narrower tires can give you higher speed through increased aerodynamics, less weight, and less rolling resistance. The downside is that narrower tires tend to be less comfortable and less grippy than wider tires.
On the other hand, wider tires can make your ride more comfortable. Wider tires can provide improved grip, and the higher tire volume provides more “cushion” to absorb bumps, and they can even reduce your risk of getting pinch flats.
You’ll have to decide what works best for you, and if you do decide to try adjusting the width, I’d suggest checking your new tire size with an expert before you put it on your bike. Safety first.
Next, we’ll get into tire tread.
Tire Tread
Tire tread is where most of your tire customization options will come into play.
Once you’ve figured out the proper size tire, you will often be able to find a variety of different tread options, that will all fit your bike.
What’s important is that you understand what role tire tread patterns play in the performance of your bike. And you’ll want to make sure you don’t accidently rotate your bike tires incorrectly and point the tread the wrong way.
Tire tread patterns are suited for different terrains and conditions. For example, the big, widely spaced knobs are great at digging into soft, loose material, like on dirt trails. The “flatter” tires with little-to-no knobs reduce the resistance between the tire and the ground, which can give you a big boost in speed and efficiency on paved roads.
There are an almost-dizzying selection of different tire tread patterns, but if you’re looking to make your mountain bike better for road cycling, you’ll want to look for something that is “slicker” than your current tires. In other words, you’ll want to get something with smaller knobs, or even no visible knobs at all.
Just keep in mind that although the reduced tread will make road riding more efficient, it also has tradeoffs. For example, your new tires may be less grippy, be hard to ride through dirt or gravel, and it’s possible that you may get flat tires more often.
Understanding how each of these tread patterns affects performance will help you find the best tire fit for your mountain bike by matching your tires to your riding style. So make sure you do your research into each tire that you consider, and when in doubt, you can always ask the smart people at your local bike shop.
Inner Tube (Size and Valve)
Finally, whenever you get a new tire, you’ll also need to make sure you have a compatible inner tube.
Look at the size details on the inner tube to make sure that everything will fit together.
You can also double check that you have the right tube valves. Tube valves come in two types; Presta or Schrader.
A Presta valve is what you will often find on road bikes and other high-end bikes. It is slender, made of metal all through, and comes with a tiny nut that seals and opens the valve. It’s about half the diameter of a Schrader valve.
Typically, Presta valves will fit into any rim. However, if fitting it into a Schrader rim, you will have to install an adapter. The adapter shrinks the hole so that the Presta valve can fit effortlessly.
On the other hand, a Schrader valve is the valve you see on cars and on mountain bikes. It is too wide that it’s impossible to fit into a Presta rim.
Is It Bad to Ride a Mountain Bike on the Road?
Now that we’ve talked about tire compatibility and sizing, let’s take a quick step back, and talk about whether or not it’s bad to ride a mountain bike on the road in the first place.
It’s not bad to ride a mountain bike on the road, and many people do it. However, mountain bikes are specially designed for off-road terrain and they are slower and more difficult to ride on pavement, compared to lighter road bikes with more slick and narrow tires.
With that said, mountain bikes are fairly versatile and a lot of people who only have one bike (confession: I have two), choose to buy mountain bikes. Mountain bikes can handle road-riding, even when there are potholes, bumps, or stretches of dirt or gravel.
Should You Replace the Wheel Also? Or Just the Tire?
If you are a beginner or a casual cycler, it’s probably best if you only replace the tire, because it’s much less complicated than replacing a whole wheel. If you want the whole wheel replaced, consider consulting a bike shop, or just having them do the hard work for you. Here are a few examples of the areas you’ll need to know about in order to correctly replace a bike wheel:
- Rim size
- Gear cassettes
- Brake compatibility
- Shock/suspension compatibility
Can You Put Hybrid Tires on a Mountain Bike?
And since we’re on the topic of customizing mountain bike tires, I thought it would also be worth addressing whether you can use hybrid tires on a mountain bike. You’ll be happy to know that the same principles apply:
You may be able to put new tires on a mountain bike that have a hybrid style tread pattern. However, you can’t simply take a tire off of a hybrid bike and install it on a mountain bike, without verifying that it fits properly. In particular, the diameter and width of a tire must be compatible with your wheel.
If you spend a lot of time on both the road and off-road terrain, you might want to install tires with a tread pattern that will help you manage both landscapes.
Summary
You have to make sure that you get a tire with the right diameter and width for your bike’s wheel. Once you’ve got your tire size locked-in, you’ll often have a variety of tire tread options, that will allow you to customize your bike to your intended terrain. Whether that be commuting on paved roads, riding dirt roads in the country, or a mix of both.