If you don’t own an electric bike, then no doubt you will have seen one pass you effortlessly on a local climb.
Their ubiquity has no doubt come down to the convenience, accessibility, and ease of use of modern eBikes. But scratch beneath the surface, and there are some subtle differences in the set-up between different eBike types.
One major difference is in the drivetrain, with some electric bicycles using a belt-drive system rather than the traditional chain-driven system.
Belt-driven systems are becoming increasingly popular for bicycles as technology improves, and belt-drive electric bikes are particularly well-suited to take advantage of the design’s unique characteristics.
If you are thinking about joining the ranks of electric bike riders and commuters, in this article, we will take a look at the different transmission systems and whether belt-drive electric bikes are superior to the traditional chain-drive system.
What Is A Belt-Drive Electric Bike?
A conventional chain-driven bicycle uses a bike chain to transfer energy from the pedals (or motor if using an eBike) to the rear wheel to provide power.
Belt-drive eBike drivetrains replace the chain with a carbon-reinforced belt featuring nylon ridges that mesh with the teeth of a cog to transfer energy to the rear wheel of the bike.
Belt drive systems go hand-in-glove with hub gears commonly found on electric bikes, as they cannot shift between gear sprockets via a derailleur. Instead of using a cassette of gear sprockets with a derailleur to shift between them, the gear system is encased within a hub on the rear wheel.
Hub gears have the advantage of not being exposed to the elements and the grime and dirt of the road, so tend to last longer with lower maintenance than traditional cog gears.
The same is also true of belt drive systems. They are robust, clean, and long-lasting.
Belt-drive systems were extremely common on the very first motorcycles in the early 1900s, but engine power rapidly increased to the point that belt-drive systems couldn’t handle the extra frictional load.
In the 1980s, Harley-Davidson went back to the belt drive system thanks to improvements in rubber and cord components that were now a match to the engine power. The belts were more durable and resistant to constant stretching.
Nowadays, you will find a mixture of belts and chains on high-end motorbikes and car engines. The great news for cyclists is that all of this technological development has filtered down to the humble bike, and nowhere is this more true than electric bikes.
The late 2000s saw a real blossoming of belt-drive technology for bikes, with major bike brands experimenting with belt drives.
Back in 2018, Veer Cycles developed an eBike conversion kit that enables people to convert their standard chain drives into belt drives by splicing the belt and removing the need for a frame with a built-in split.
Are Belt-Drive eBikes Better Than Chain Drives?
3 Key Advantages Of Belt-Drive Electric Bikes
#1: Low maintenance
Coupled with hub gears, belt drive systems are much lower maintenance than chain-drive systems. They rarely require adjusting or indexing.
They are cleaner than oil-soaked chain-driven systems. The relative lack of lubrication also means they pick up less road grime and can be easily cleaned. Maintenance of belts is often as easy as giving them a good wipe-down when you start to notice some dirt.
Given that many electric bike users tend to be relatively casual cyclists, and therefore might be less confident doing their own repairs and maintenance, this is a major advantage.
#2: Belt Drives are Quieter
The materials used in belt drive systems mean a much quieter drive system compared to chain drive systems, where metal-on-metal contact inevitably makes a sound.
This is particularly convenient for an electric bike, for which the relative silence of use is one of the major attractions for some riders.
#3: Belt Drives Last Longer
Modern belts don’t stretch or wear as quickly as bike chains and therefore need replacing less often.
As bike chains stretch and wear, they need to be replaced, usually along with the cassette and chainrings.
A typical chain will require changing after roughly 3000-5000 miles (depending on the conditions you ride in), whereas a belt drive can last 10,000-20,000 miles.
Belts are also gentler on the teeth of gear cogs, meaning they also need to be replaced less frequently.
This is particularly important for electric bike drivetrains because the additional power of the motor can accelerate component wear within the drivetrain.
Credit: Robbie Ferri
4 Disadvantages Of Belt-Drive Electric Bikes Vs Chain-Drives
#1: Only Compatible With Hub Gears
Although more of a feature than a bug, belt drive systems are only compatible with internal gear hubs since there is no lateral flexibility in the belt.
This rules out any system using cogs and sprockets.
#2: Belt-Drive Systems are Heavier
Belt-drive gearing systems tend to be heavier and have less range than chain-and-derailleur drivetrains.
However, this is less relevant for an electric bike, as they tend to be significantly heavier than traditional bikes anyway – plus the motor on an eBike more than compensates for the extra weight and lack of gearing range.
#3: Belt-Drives are more Expensive
Although they are longer lasting than chains, belt drives for electric bikes are considerably more expensive to replace.
#4: Difficult To Replace
Since a belt is a single, continuous piece, it cannot be easily split for removal or maintenance.
A chain tool is all you need to remove a chain link, but with a belt-drive electric bike, the frame itself needs to have an opening to allow the belt to pass through and onto the transmission.
Are Belt-Drive Electric Bikes The Future?
The electric bike market is huge and growing. It is currently valued at around $51.5 billion, which is predicted to rise to $77.2 billion by 2028.
This growth is driven by many factors, but perhaps none more than rising energy costs and general inflation forcing car users to look into more economical ways of commuting or getting around.
As cities experiment with low-emissions zones to help clean the air and make urban environments more pleasant for pedestrians, electric bikes are seen as a viable alternative to the internal combustion engine.
As the eBike market grows, so too will the development of belt-drive electric bikes.
One area where we are likely to see huge belt-drive eBike growth is in the cycle share schemes that operate across many cities.
These have evolved rapidly from the docking stations used by the original London “Boris Bikes” to modern smart bikes that use GPS technology and connect directly to an app on the user’s smartphone, and their popularity is exploding in cities around the globe.
The advantages of belt drive systems make them ideal for these mass-use eBikes.
They are practically maintenance-free for long periods, they are clean, and they last a long time, meaning that these bikes should rarely have to be taken off the roads for repair and servicing (notwithstanding battery issues such as charging).
Now you’ve read the article, the only question remaining is, how long before an eBike makes its way into your bike collection? And will it be featuring a belt drive or chain system?
Let us know below!
