Hub gears: Everything you need to know

One of the most important parts of an electric bicycle is the gear system. Nowadays, most electric bicycles use an internal hub gear, developed as a more efficient and reliable alternative to chain gears.

As with most e-bike parts, manufacturers develop hub gears in different ways. This can make it difficult to find out which gear system best suits your needs. Understanding the differences between the two gear systems can help you make an informed decision.

In this article, you will learn all about hub gears: what they are, how they work, and their advantages and disadvantages. We will also help you choose the right hub gear for your electric bicycle.

What are hub gears?

A hub gear is a shifting system designed for both traditional bicycles and electric bicycles. It is a central unit installed in the rear wheel that contains a set of planetary gears.

Bicycles with hub gears allow you to switch between two and 14 gears. Some hub gears offer even more gears but are more expensive. Additionally, the weatherproof unit protects the internal parts from external influences.

How do hub gears work?

Different e-bike makers develop their hub gears in various ways. Most, however, are based on a planetary gear system. Several gears inside rotate around a central sun gear.

When shifting, the positions of the planetary gears change. Different arrangements in the planetary gear system result in different gear ratios. All this happens without an external shifting system like a chain gear.

Hub gears vs. chain gears

Hub gears and chain gears differ in many ways. The two main differences lie in how they work and the benefits they offer.

A chain gear system consists of a chain stretched between two wheels, several sprockets, and a mechanism that moves the chain from one sprocket to another. Smaller sprockets make climbing easier, while larger sprockets allow for higher speeds when going downhill.

Hub gears, on the other hand, are almost entirely housed in a closed unit, except for the connected chain or drive belt. This design protects the internal parts from damage.

Advantages and disadvantages of hub gears

Advantages

• Most parts of a hub gear are housed in a weatherproof unit. This protects the internal parts from dirt, dust, and moisture, which increases lifespan and reduces maintenance effort.
• Hub gears require fewer oil changes than chain gears and usually only need professional maintenance once a year.
• Another advantage is that the gear system is always engaged. This means you can shift while standing still, which is not possible with a chain gear. This is especially useful for quicker starts from a stop.

Disadvantages

• The main drawback of hub gears is their weight and price. An average hub gear weighs about 1 to 1.5 kg, but more complex systems can weigh over 2 kg.
• Also, hub gears are more expensive to produce and maintain than chain gears. Nevertheless, brands like Shimano are working to offer high-quality and affordable hub gears.

Types of hub gears

Here are the most common types of hub gears for electric bicycles:

1. 3-speed hub gear: Often found in entry-level e-bikes, ideal for flat, urban, or suburban areas.
2. 4-speed hub gear: Suitable for light terrain and steeper climbs.
3. 5-speed hub gear: Perfect for more demanding trails and hilly terrain.
4. 7-speed hub gear: Offers a wider gear range for more versatile use.
5. Enviolo Continuously Variable Hubs: An innovative technology that allows seamless shifting, even while standing still.

Hub gears and e-bikes: the perfect combination

The combination of hub gear and electric bicycle is an ideal solution. You can shift while standing still, produce less noise, and save on maintenance costs. At the same time, the pedal assistance of an e-bike allows longer rides with less effort.

Choosing the right hub gear

Consider your individual needs:

• A 3- or 4-speed hub gear is sufficient for flat, urban terrain.
• For hilly and rough terrain, 5- or 7-speed hub gears are better suited.

Care and maintenance

Keep your hub gear in optimal condition:

• Follow the manufacturer's recommended maintenance intervals.
• Change the oil at least once a year.
• Keep the external chain or drive belt clean and lubricated.

Conclusion

A hub gear is a versatile and practical shifting system. The weatherproof unit protects the parts and allows for a long-lasting, low-maintenance riding experience. The ability to shift while standing still is another great advantage.

Discover our selection of electric bicycles with hub gears and experience the benefits yourself – ideal for commuters and available in a variety of sizes and colours.