Steep Hill Climbing: Are Electric Bikes Up for the Challenge?

One of the biggest selling points of eclectic bikes is that they help you maintain a constant speed. While most manufacturers advertise that this assistance extends to hills, they often don’t specify how steep those hills are. So, can electric bikes climb steep hills? And how steep?

Most electric bikes are suitable for hills of up to 10% gradients, but 6% is more comfortable. Electric bikes vary in design according to their intended purpose, and some electric bikes are better suited to managing hills than others. For example, bikes with larger motors are usually better.

While electric bikes make our lives easier by maintaining a constant speed, their performance is limited by several factors. This article explores some of the limitations surrounding electric bikes and steep hills, including slope ranges, if wattage plays a role, and potential workarounds for those (unavoidable) steep hills.

How Steep, Is Too Steep For An Electric Bike?

The first important question is, what type of electric bike are you looking at? Electric bikes (e-bikes) are designed to fulfill a particular need. For consistency, we’ll look at recreation/road e-bikes.

The next important question is, “what constitutes a steep hill?” A “steep” slope is any hill that has a gradient of greater than 15% (16 to 30%). I.e., a road that increases in height (goes up vertically) by 15 feet over 100 feet (horizontal).

We can divide the slope into the following categories:

  • 0 to 3% – no to little slope, making an easy ride.
  • 4 to 9% – gentle slope. Most riders find the slope between 4 and 6% manageable; however, as you approach 7 to 9%, the going becomes tough, even for experienced riders.
  • 10 to 15% – moderate slope. This slope is not comfortable for most riders and quickly leads to fatigue.
  • 16 to 30% – steep slopes. From here out, you’re looking at mountain riding and other tough terrains that make riding for beginners or “causal” e-bikers unpleasant.
  • 31 to 60% – extremely steep slopes. Most riders won’t attempt any slopes in this category.
  • More than 61% – excessively steep slopes. Take a bus.

While mountain e-bikes are designed with rough terrain in mind, recreation/road e-bikes usually don’t go on roads greater than 10% (which equates to roughly a 6° angle).

I.e., a 45° angle equals 100% road gradient, while a 6% gradient is around 3.4°(what most highways are limited to). E-bikes are unsuitable for cliff faces, and the closer you get to 45° (or 100% road gradient), the more the bike will struggle.

How Long The Hill Is Determines How Well Electric Bikes Perform

Most recreation e-bikes are sufficient for handling the majority of hills you may encounter (even if their speed might be left wanting.) However, the hill’s length plays a fundamental role too.

While most e-bikes handle short “bursts” up steep gradients, traveling up steep inclines drains the battery and produces excess heat. This “wear and tear” will limit how far (and steep) you’re willing to push your bike.

Aside from the hill, other factors contribute to how steep an e-bike can go.

What Are Some Limiting Factors For Electric Bikes And Hills?

While most e-bikes can climb a 10% slope, there are some limiting factors to consider.

Most of these points interact with one another (they are not isolated).

The Weight And Experience Level Of The Rider

The most significant contributing factor to if a bike can go up a steep hill (and how quickly) relates to the rider’s weight. Heavier riders mean the e-bike needs more power to climb steep hills (if you think back to physics 101).

So, there is a point where rider weight inhibits the e-bike from hill climbing. Most e-bikes can accommodate a 220lb adult up a 10% slope (including the 250w motors).

Most e-bikes carry a weight restriction of 275 to 300 lbs, but several models push beyond this weight range.

Your riding experience and how well you work the gears are pivotal in getting the most torque out of your e-bike to climb steep hills. You’ll often need to pedal to help the e-bike up the hill (particularly smaller motors), so there is a fitness element too.

Understand how different motors impact an e-bike's climbing ability.

How heavy the e-bike is also contributes significantly. Some e-bikes are trimmed down to be weight-efficient, while others (like the beach cruisers) are usually heavier. This extra weight requires more power to go up a hill.

The Terrain

Most recreational e-bikes can manage up to 10%, provided you stick to the road. Any amount of “off-road” (dirt) riding will limit the maximum gradient of your e-bike.

While mountain e-bikes are built with stronger and lighter frames, most beach cruisers will struggle to go off-road.

Motor Size (Wattage)

E-bikes with more powerful motors (higher watts) can carry more weight up a steeper hill (or the same size hill, quicker).

For example, a YouTube video by Electric Bike Report compared a 500w and a 750w e-bike up the same hill, and (unsurprisingly) the 750w performed better (although both e-bikes made it up the hill without any issues).

The hill test is between 12 and 15%, comfortably in the “steep” category. Most hill-rated e-bikes are 500w or 750w. Although a 250w can go up a hill, the extra wattage/power is better for the motor and battery.

The two bikes in the experiment were classed as “beach cruisers,” and handled the ⅓ of a mile hill in a great time.

The 500w made it up the hill in 1 minute 35 seconds, while the 750w made it in 1 minute 19 seconds on the throttle only. While on the pedal assist, the 500w made it up in 1 min 11 seconds, and the 750w made it in 1 minute 1 second.

Rear Hub Vs. Mid-Drive Motor

Mid-drive motors make better hill climbers. They are superior at using fewer watts to create more power thanks to their drivetrain’s relationship with the gears (applying more torque/power and improving the speed).

Learn the difference between torque and watts in relation to an e-bike's hill-climbing capacity.

Rear hub motors “lose out” on some of the power conversion as the motor powers the back wheel directly.

Throttle Vs. Pedal Assist Up Hills

A pedal-assist e-bike means you’ll need to put in considerably more effort going up a steep hill, while throttle e-bikes are significantly easier.

However, pedal assist means that the e-bike carries less of the “burden” while you’re helping it along, usually making the process much quicker.

The Electric Bike’s Purpose/Design

A mountain e-bike is better suited for heading up steep hills than a cruiser/road e-bike. Mountain e-bikes are lighter, have stronger frames, and have better suspensions. These variables impact the performance up a steep hill.

Understand the role of suspension in e-bike's hill climbing performance.

The question is. Why do you need an e-bike to go up hills? Is it part of your daily commute? Are you into cruising in areas with a lot of hills? Do you live in a hilly area? Or are you looking to go adventure biking?

Most e-bikes on the market meet these needs, barring those who want to try and ride up mountains along dirt trails.

Some e-bikes designed for hills include:

  • HalloMotor 5000W FC
  • E-Cells Super Monarch Crown
  • Addmotor Motan
  • Cannondale Treadwell Neo 2 EQ

How Well The Motor Is Tuned

The e-bike’s purpose usually determines how well “tuned” the bike is.

There are 3 e-bike classes:

  • Class 1 – These e-bikes work on a pedal-assist system and are limited to 20 mph. While some models have throttles on the handlebars, they only work if you keep pedaling.
  • Class 2 – These e-bikes are also limited to around 20 mph, but their throttles work without needing to pedal, pedal assist is still a major feature for most models).
  • Class 3 – These e-bikes are regulated to 28 mph and come in throttle and pedal assist models (some states allow you to use the throttle to 20 mph, while if you want to reach the top speed, you’ll need to pedal).

The class of the e-bike will determine how well-suited it is to go up steep hills (how fast it will go and how much effort you need to put in before the motor switches on to assist you).

Bikes tuned to have greater torque usually fare better on steep hills, as torque translates to power.

Find out how to increase torque for better hill climbing.

How To Improve An Electric Bike’s Hill Performance

While many of us disdain hills, they are, unfortunately, unavoidable. Below are some points to remember before setting out to conquer your next mountain (or molehill).

Stay On Top Of The Electric Bike’s Maintenance

Before heading out on your e-bike, ensure that the tires are pumped correctly, the battery is fully charged, the motor works properly, and no errors are displayed.

Learn if fat tires can improve your e-bike's ability to climb steep hills.

Your e-bike will perform at its zenith by staying on top of maintenance.

Your Body Position Is Paramount

Leaning forward while pedaling up a steep hill gives you a better angle on the pedals and helps you feel like you’re not about to fall backward.

Sometimes standing up is what it takes. The motion is more natural, and you can power through steep sections easier than while seated.

Keep A Steady And Consistent Pedaling Rhythm

Few things are more debilitating when riding a bike (e- or normal) than losing the pedaling rhythm.

Maintaining a rhythm keeps your momentum; however, if you break it, you’ll need to put in considerably more effort to get going again.

Select A Suitable Gear For The Hill

Most e-bikes have gears, which make a world of difference up a hill. Drop a gear or two if you struggle to keep a constant rhythm. You’ll go slower but have better torque for those inclines.

Build Up Your Endurance/Fitness

Getting off and pushing is a fine alternative to injuring yourself, but make a mental note of the hill and practice on smaller hills/going further up the hill.

You’ll move to the next mountain at the end of a few weeks!

Conclusions

Although most electric bikes are rated for 10% slopes, most roads are less steep. Electric bikes from 250w to 750w can climb hills, but the rider’s weight is a significant limiting factor. Higher-wattage e-bikes are usually better up hills but over short distances. If you’re an avid hill climber, consider purchasing a mountain electric bike.

Discover potential upgrades to enhance your e-bike's climbing ability.

Author

  • Miles Baxter

    Miles Baxter is an engineer with a longstanding love for bicycles, sparked by winning a mountain bike in a childhood lottery. Balancing a keen interest in mechanics with the thrill of biking, his career is a testament to the art of turning wheels and gears into adventures.

    Baxter Miles