Internal Gear Hubs: Everything You Need to Know

One of the most important components on an electric bike is the gearing system. These days, most electric bikes use an internal gear hub designed to be a more efficient and reliable alternative to derailleur gears.

However, like most electric bike parts, manufacturers develop derailleur gears differently. This can make it hard to know which gearing system will best meet your needs. Understanding the differences between the two gearing systems can help you make an informed decision。

In this article, you’ll learn all there is to know about internal gear hubs. You’ll discover what they are, how they work, and their pros and cons. From there, we’ll help you choose the right internal gear hub.

What Are Internal Gear Hubs?

An internal gear hub is a gearing system designed for traditional pedal and electronic bikes. It has a centralized unit installed onto the rear wheel, housing a series of planetary gears.

Bikes with hub gears let you switch between two to 14 gear ratios. Some gear hubs can reach even more gears, but they come with a higher price point. Plus, the weather-proof unit helps protect the internal components.

How Do Internal Gear Hubs Work?

Different e-bike manufacturers develop their internal gear hubs in different ways. However, most operate on a planetary gear system. Under this system, the hub has multiple gears on the inside, rotating around a central sun gear.

When you switch gears on an electric bike with an internal gear hub, the position of the planetary gears changes. Different arrangements of the planetary gear system result in different gear ratios. In addition, this all happens without an external derailleur system.

Internal Gear Hubs vs Derailleur Gears

Internal gear hubs and derailleur gears are different in many ways. The two key distinguishing factors are how they work and the benefits they offer.

A derailleur gear system consists of a chain stretched between two wheels, multiple sprockets, and a mechanism that moves the chain from one sprocket to another. When you change gears, the chain moves to sprockets of different sizes. Smaller sprockets make it easier to climb uphill, and larger sprockets help you go faster when riding downhill.

Internal gear hubs, on the other hand, work differently. The entire gearing system is housed almost entirely in an enclosed unit, excluding the connected chain or drive belt. This design helps protect the internal components from damage.

Pros and Cons of Internal Gear Hubs

An internal gear hub’s design has many pros and cons. Let’s explore these in greater detail.

Pros

For one, most of the components on an internal gear hub are housed in a weather-proof unit. This helps protect the internals from damage caused by exposure to dirt, dust, and moisture. The result? A longer-lasting gearing system and lower maintenance requirements.

In fact, internal gear hubs require fewer oil changes than derailleur gears. And typically, you only need to get it professionally serviced once per year. However, that depends on the e-bike manufacturer and where and how often you use your electric bike.

Another great thing about an internal gear hub is that the gearing system is always engaged. This means you can change gears while stationary, which is impossible on a derailleur gear system. It’s a great way to get a head start when accelerating from an idle position.

Cons

The main drawbacks to an internal gear hub are its weight and price.

The average internal gear hub weighs around 1 to 1.5 kg. However, more complex systems can weigh 2kg or more. On paper, this may not sound very heavy. But, when you factor in all the components on an e-bike, even a few extra kilograms can make all the difference.

Also, internal gear hubs are more expensive to manufacture and maintain than derailleur gear systems. However, brands like Shimano are producing internal gear hubs that are both high quality and affordable.

Types of Internal Gear Hubs

Below are the most common types of internal gear hubs that you will find on an electric bike.

3-Speed

Typically found on entry-level electric bikes, 3-speeds are the most common and affordable type of internal gear hub. They are ideal for leisurely riding in city or suburban areas with flat, smooth terrain.

4-Speed

The next step up is 4-speed internal gear hubs. With one more gear than 3-speed hubs, you can adapt to a variety of situations. This makes them ideal for climbing steep inclines and light off-road trails.

5-Speed

With a 5-speed internal gear hub, you can tackle tougher riding scenarios, such as heavy-duty off-road trails and steeper inclines.

7-Speed

A 7-speed internal gear hub is one of the most versatile systems. It gives you the full gear range to choose from so that you overcome the toughest riding scenarios.

Enviolo Continuously Variable Hubs

Previously known as NuVinci, the Enviolo Continuously Variable Hub (ECVH) is a new type of hub in development. Still a niche technology, the Enviolo CVT transmission allows for reliable shifting at a standstill. They also promise more seamless gear shifting and a reduced chance of the chain falling off.

Internal Gear Hubs and E-Bikes: A Perfect Match?

Internal gear hubs and electric bikes are a match made in heaven. By combining the two technologies, you enjoy the best of both worlds.

An internal gear hub lets you change gears at a standstill. You also produce less noise than a derailleur gear system and save time and money on maintenance.
Meanwhile, the pedal assist on an electric bike helps propel you forward. This way, you can ride further with less pedaling effort than a conventional bike.

Choosing the Right Internal Gear Hub for Your E-Bike

When shopping for an electric bike with an internal gear hub, consider your needs and preferences.

Will you ride on mostly flat, smooth terrain in the city or the suburbs? With a 3- or 4-speed hub, you can overcome most metropolitan scenarios. Or will you be riding on rough terrain and steep inclines? With a 5- or 7-speed hub, you can choose from a wider range of gear ratios.

Maintenance and Care of Internal Gear Hubs

• To keep your internal gear hub in optimal condition, follow these maintenance tips:
• Follow your manufacturer’s recommended service interval
• Perform an oil change at least once per year
• Ensure the external chain or drive belt is clean and lubricated

Final Thoughts

An internal gear hub is a convenient and versatile gearing system. The weather-proof unit helps protect the internals from damage, increasing its lifespan and reducing maintenance. Plus, the ability to shift gears at a standstill helps you accelerate faster from zero.

Explore our range of electric bikes to discover the benefits of internal gear hub electric bikes. These bikes are ideal for commuting and come in a range of sizes and stylish colours.