Road Bikes are indeed faster than Mountain Bikes.
The difference averages out to around a 10%-30% increase in speed. This is impacted by many factors such as weight and aerodynamics.
This article explores just how much faster Road Bikes are, and what that actually means for you. There are lots of things to consider, including:
- What kind of terrain you’re going to be travelling on
- The kinds of speeds to expect from different bikes on different terrains
- Factors that influence the speed
- What this all means for you
We’ve got all this covered in this article.
Speed Variation – Mountain Bikes Vs Road Bikes
It is noted that the variation in speed is much higher in mountain bikes when you take into account the steep inclines, climbing, and descent in any given mountain trail or route.
It is also worth mentioning here that different kinds of terrain yield different results in terms of speed, for example, grass compared to gravel.
What does help is an understanding of the different factors that impact your bike’s speed and acceleration, so you can make an informed decision when you decide to purchase a bike.
While not an exhaustive study, this video by the Global Cycling Network (GCN) is a good comparative analysis of what speeds and difficulties one can experience when on a trail or a road route.
The average speed of the Mountain Bike rider was recorded at 8.18 km/h which was much slower when compared to the Road Bike rider, who had an average speed of around 24.80 km/h.
More than anything, this shows that your mileage may vary depending on the routes you choose to take, which ends up being more important than the top speed of your model of bike.
It should also be noted that during descents from mountain tracks, your speeds can be considerably higher due to the momentum built up.
To gain more perspective, we can look at the follow-up video by the Global Cycling Network (GCN). When tested on different routes with varying terrains, we find out about the maximum speeds they achieve during their race.
The Mountain Bike, when given a decent off-road trail, managed to reach a maximum speed of 56.00 km/h off-road.
The Road Bike managed to reach a substantially higher speed of 66.00 km/h.
To achieve rather similar speeds, the maximum wattage of power spent is remarkably higher, and henceforth, takes a lot more effort.
The Road Bike community is very different from the Mountain Bikes community. The former is focused on speed and intense cardio-based workouts while the latter is relaxed and more prone to exploring different sites with friends.
Both mountain and road bikes are equally welcoming and competitive.
Regardless of which bike you choose, you are still helping to eliminate harmful CO2 waste from the environment, which the exhaust of other vehicles expel when on the road.
Let’s have a look at the two most common types of bikes that you can buy.
Factors that Impact Speed
Posture and Physical Health
Both types of bikes are ridden in different ways, meaning your posture on a mountain bike is upright, which is one of the primary reasons they are slower, whereas your body becomes the biggest source of drag force and air resistance when it comes to riding a bicycle.
On a road bike, one tends to be more tucked down due to the nature of their narrower aero-bars, which increases your acceleration and speed.
The handlebars on a Mountain Bike are flat but offer more control and make braking easier. However, that does make it significantly more stressful for your wrists and back in the long term.
The drop handlebars, or aero-bars, are usually not very wide which makes it easy to tackle smaller gaps.
Furthermore, bikes are merely vehicles that are as good as their bikers. A person’s physique, stamina, and fitness play a large role in how fast they can go on a bike.
Your mileage may significantly vary depending on your physical health and it is mostly only professional bikers who consistently achieve 25+ mph on Road Bikes.
For most novice riders and fitness cyclists, the difference in top speed is less substantial and their primary concern is average speeds and acceleration.
A primary factor with a large stake in the speed difference is the nature of the tires. This includes their width, pressure, diameter, and treading.
On-road bikes, the tires have lesser width (approximately 700c-sized) and almost no treading along their curvature, allowing them to cruise through paved roads so long as there are no obstacles on their way (Source).
Mountain bikes, on the other hand, are a completely different story. They require additional grip and hence have protruding knob-like treads on the wheels which help in the overall performance of the bike.
The wheels of a mountain bike are wider as they need to be able to traverse across much more difficult terrain than a Road Bike would.
The treading, sometimes referred to as the raised aggressive lugging, acts like claws that grip onto the soil when going over it and provide control at the cost of speed.
It is important to know that due to how rugged and rigidly built Mountain Bikes are, they tend to be significantly heavier than their Road Bike counterparts.
At the most, this weight difference could add up to three to five kilograms, causing a mile-per-hour difference in speed. (Source)
This is due to the components on a Mountain Bike, it ranges from the wheels to the tires and is essentially heavier because it needs to be a lot more durable.
The added weight of the tires with wider raised lugs also decreases the rate at which you can accelerate, hence slowing you down further.
We can get some perspective on this by looking at a group set, which includes the parts involved in a bike’s braking system. This includes, but is not limited to, shifters, brake levers, front and rear calipers, chain, cassette, bottom bracket, crankset, and more (Source).
Road bikes have lightweight group sets that are rather costly. This applies more to race-bikes, where the reduction of every gram is necessary. However, on a mountain bike, the group set and construction are much heavier.
Gear Ratio and Frame Geometry
Just by their purpose and how they are built, mountain bikes and road bikes have drastically different speeds.
The build and design of a mountain bike place emphasis on the bike staying stable on rough terrain, while the frame geometry of road bikes emphasize aerodynamic paddling.
Mountain bikes also tend to have smaller gears as they are meant for off-road purposes, a subtle difference that becomes apparent at higher speeds.
They have a lower upper gear, which means that despite having a higher power output, they have a smaller top speed (Source). This is important as they have to climb up rather steep inclines, which most Road Bikes do not deal with.
A majority of the decrease in speed is attributed to the mechanical limitations of the gear set. This decrease could be substantial depending on your gear set specifications such as chaining teeth, crank length, wheel size, and more.
For example, the rear cassette is slightly smaller on Mountain Bikes, as they have more gear groups to distribute force to.
Speaking of their chains, Mountain Bikes tend to have two chainrings whereas most Road Bikes tend to have three chainrings.
This means you cannot swap them, even if you have read articles that encourage it or have heard it through friends. This will only end up causing damage to your bike.
It is also worth noting that Mountain Bikes are built with softer frames and suspension systems that absorb shocks through springs. However, this takes additional effort from the biker as the bike needs more pedal energy to accelerate and function as intended.
When it comes to Road Bikes, the stiffer frames ensure that less power is lost to a suspension system, and more of it is transferred to the wheels for maximum speed.
What is a Road Bike?
Road bikes are mostly intended for tackling a daily commute within an urban setting, but they do have a history and heritage of being used for racing.
They are meant for speed, with lightweight construction and smooth narrow tires that let you just blast through paved surfaces.
They are so well-known for their speed that they have recently become featured with disc-brake variants. They are still most commonly used for recreational riders. They also come in many different varieties, namely: Aero, Ultralight, Endurance, Touring, and All-Road. (Source).
Road Bikes work great for anyone wanting to rank up miles and covering long distances or be part of group cycling sessions where everyone assists each other.
However, being aware of their high cost, the occasional flat tire, and other pesky vehicles on the road will help make your experience safer and better.
What is a Mountain Bike?
If exploring dirt trails is a hobby for you, then mountain bikes might just be perfect for you. Conceptualized in the early 1970s by people hoping to escape their noisier urban settings (Source), they are designed with durability in mind.
Their rugged heavy builds, when paired with their large treaded tires and suspension systems, ensure that you can cover any trail comfortably. It is important to note that because of their weight and suspension systems, they take significantly more effort, up to 51%, to ride (Source).
This statistic does not take into account suspension, which would cause the number to go up to 100% to 150% for approximately the same 10 to 15-mile distance. Their primary selling point is their versatility across many different types of terrains.
Similar to Road Bikes, Mountain Bikes also come in many different varieties, namely: Hardtail, XC – Full Suspension, Trail – Full Suspension, and Endura Full Suspension (Source).
The best part about having a Mountain Bike is the beautiful scenery you get to see as you traverse through the trails. The comfortable, albeit harder ride is only icing on the cake.
However, be wary of how frequently you have to clean them and the risk of injuries that accompany off-road riding.
The Bottom Line
A lot of what is discussed above boils down to personal preference. It isn’t enough to have the fastest ride, but the ride that is most mentally and physically rewarding to you. It is important to know about factors, such as weight or tire width which impact speed so that you can make a more informed decision when you decide to purchase your bike.
To emphasize this further, it is important to remember that many aspects of bikes are customizable (Source).
Anything from the seat to the handlebars can be changed or tweaked for the rider’s benefit, so this article mostly serves as a general analysis. One can drastically improve the speed of their Mountain Bike through a locked suspension, clipless pedals, and high-pressure tires that can significantly reduce rolling resistance.
While there is a notable speed difference of 1mph to 2mph at best, this is one of many considerations when it comes to choosing a mode of biking. What is more critically important is that you enjoy whichever type of bike you end up using.