Going downhill on a bike is one of the most exhilarating moments while riding a bicycle! This is because bikes descend while picking up speed without much effort from the rider.
Since going downhill on a bike is always associated with high speed, a lot of people might wonder “how fast can a bike go downhill?”.
If you want to know more about cycling downhill, how fast you should go, and how to stay safe while doing so, this guide will have what you’re looking for. Let’s dive right in!
How Fast Can a Bike Go Downhill?
Technically speaking, bikes can go downhill at extremely high speeds, provided that all the conditions and factors are in their favor.
For example, on the downhill parts of most regular situations, the speed of the bikes will peak at about 17 to 30 mph (27.3 to 48.2 km/h).
However, a bike can reach maximum speeds of up to 65 mph (104 km/h) depending on the bike and the rider. This includes riders in the downhill section of the Tour de France, where riders are even able to lose reporters on motorbikes.
In other words, there are plenty of factors that play a huge role in the speed at which your bike is going downhill.
Factors That Affect the Speed of the Bike While Going Downhill
Now that you know that there are various factors that can affect the speed of your bike while going downhill, here’s a quick look at these aspects:
Type of the Bike
There’s a wide range of bikes out there, such as cruiser bikes, mountain bikes, racing bikes, and much more. Of course, some of these bikes are built so that they can perform better while going downhill.
For instance, racing bikes are built with materials that make the bike’s acceleration much easier and quicker. This allows the bike to pick up as much speed as possible while going downhill.
The Condition of the Bike Components
The condition of the bike also has an impact on the speed of the bike while going downhill. Ideally, a new bike with proper lubrication of the derailleur as well as other parts of the system means quicker response to the gravity, and therefore, speeding up to the terminal velocity in less time.
The Aerodynamics of the Rider
If you’ve been around the cycling community for long enough, you’ll know how important aerodynamics is riding a bike.
While riding a bike, you create a lot of wind, even if you’re cycling on a day where there’s no wind at all, which is called “aerodynamic drag”.
In fact, as soon as you exceed 9 mph (14.5 km/h), about 50% of the force acting on you is air resistance. As you reach 30+ mph (48 km/h), up to 90% of your power is spent overcoming air resistance.
In other words, if you maintain high aerodynamics and minimize air resistance, you should expect to go downhill much faster.
The Slope and Distance of Descend
It goes without saying that the longer and the deeper the slope of the downhill section, the faster your bike will be.
The size and weight of the rider also affect the downhill speed because bigger riders have a larger sectional density, provided that all other variables are equal in that case.
What is the World Record for the Fastest Downhill Speed on a Bike?
The world’s record for the fastest speed ever reached by a cyclist while going downhill belongs to the Austrian cyclist Markus “Max” Stöckl, while he was sponsored by RedBull.
The record was broken in 2017 when Max reached a top speed of 104.1 mph (167.6 km/h) in the Atacama desert in Chile over a mountain bike.
Max picked the desert mountain Cerro el Flaco to descend, which is 3,972 meters (about 13,000 ft) high and has a slope of about 1,200 meters (3937 ft) long to break the record.
What is the Highest Downhill Speed for Safe Braking?
Descending downhill might be quite exciting but the faster you go, the harder it’ll be to stop the bike when you need it to.
As you’ve noticed, the fastest speeds achieved while going downhill are usually achieved while cycling in controlled areas where no variables are on the way, such as road animals, bumps, traffic, or side roads are in the way.
However, while going downhill on real roads, going faster than you’re capable of stopping can be quite dangerous.
After all, bike brakes are much simpler than car brakes and will overheat and underperform when you’re going too fast.
Ideally, you should also try to limit your downhill speed to under 35 to 40 mph (56 to 64 km/h) in order to maintain a speed that you’re capable of stopping at the right time.
Will Going Downhill at High Speeds Damage the Bike?
If your bike is in good condition before going downhill, it’s quite unlikely for the bike to fail while picking up the speed downhill. However, there’s a limit to which the bike’s components will start to give in.
For instance, if you maintain the speed of the bike at very long distances, the tires will start to become a bit unstable due to wobbling and warping.
Additionally, applying the brakes at extremely high speed or for extended periods of time can cause the brakes to wear and fail.
What is the Ideal Body Position While Going Downhill on a Bike?
In order to maintain the maximum speed without compromising on your safety, you need to make sure that you position yourself properly while going downhill, which is slightly different from how you sit while riding a bike casually.
Keep Your Joints Bent
Most beginner bikers will brace while going downhill by keeping their elbows straight and locking in position.
The problem with this position is that it helps bikers levitate while jumping, so it can make you pretty unstable. Also, it puts all the pressure from shocks on your arms, which are handling the bike.
Instead, you need to keep your knees and elbows bent without locking them. This way, you’ll be able to react to the terrain and help your joints to absorb shocks and act like additional suspension.
Lower Your Heels
You also need to brace your feet against the bike’s pedals by dropping the heels, which also improves your stability level.
Shift Your Hips and Backside Back
Adjust your backside so most of your weight is centered at the level of the seat while keeping your shoulder relaxed. This should help you maintain your center of gravity stable and prevent sudden jerks.
Despite having a solid standing pose, it’s important to get a good grip on your front and rear brakes without applying too much pressure that you start to squeeze them.
Lower Your Chest
By keeping your chest and chin over the stem during the descent, you’ll make sure that your center of gravity remains in the middle of the bike, which doesn’t put extra weight on either the front or the rear wheels, which makes you lose control.
Tips to Descend Downhill Safely
Lastly, here are some essential tips to maintain your safety if you’re into going downhill with your bike
1. Perform a Thorough Check of Your Bike
As previously mentioned, going downhill at high speed is pretty demanding and can only be safe if your bike is in good condition.
Before attempting to go fast on any steep slopes, make sure that your brakes are in good condition.
Additionally, you should get the brakes checked at least once every 6 to 12 months and replace them whenever they show signs of wear.
In addition to the brakes, you need to check the frame of the bike and make sure that it can handle shocks at high speed.
2. Optimize the Tire Pressure
While checking the tires, you should make sure that the pressure is set at 110 PSI (pounds per square inch).
This tire pressure maintains a good balance between grip and speed on the road.
For mountain bikes or bikes with wider tires, you might need to set the pressure a little lower to make up for its size.
3. Unlock the Handlebar and Wheels
Make sure that you also unlock the handlebar while going down the road, which is essential to prevent skidding on the road.
4. Keep Your Eyes Ahead
Always keep your eyes in a position where it scans the road ahead for any bumps or stones that need to be avoided without keeping your eyes fixed on a specific point.
With that said, you now know how fast a bike can go downhill, whether on an average or a professional level.
As you can see, picking up the speed while going downhill is pretty easy. However, it’s always essential that you stay focused and watch out for any bump or humps that can cause you to lose your balance while descending.