Belt drive vs chain: Which is best for your ebike?

If you’ve been considering buying your first ebike — or perhaps your second or third — chances are you’ve come across some models equipped with a belt drive instead of a traditional chain. But what difference does a belt drive really make, and is it actually worth the usual premium over a tried and trusted chain?

We’re here to help.

What is a belt drive?

Until ebikes started to become popular, almost every bicycle on the market used a chain. But the advent of ebikes has increasingly made belt drives a popular alternative. The Gates Carbon Drive is by far the most popular of these, and it’s the one we’ll focus on the most. There are some alternatives too, but Gates’ belts are so ubiquitous that unless otherwise specified, you can assume we’re talking about this one brand. This isn’t a sponsored post or anything, it’s just the nature of the market right now.

Anyway, to answer the question: at its most basic level, a belt drive is exactly what it sounds like. Instead of a chain transmitting power from your legs to the rear wheel, a belt does the job instead.

Duh, but what’s the point of using a belt?

The most often-cited benefit to a belt drive is durability. The Gates Carbon belt drive is reinforced with — you guessed it — carbon fiber. In case you haven’t heard, that stuff is pretty tough.

Gates’ carbon fiber belts were originally designed for high-power applications like motorcycles and industrial machinery. Ebikes are comparatively puny, so they should pretty much last forever. Gates says its CDX CenterTrack belt is rated for 10,000 miles under peak loads, while chains designed for ebikes “failed at only 275 miles.” In real-world usage, its ebike chains should be replaced every 2,000 miles, while a Gates belt is should last you up to 19,000 miles.

Of course, we’re taking Gates’ word for it here, but in my experience, hearing of a belt drive failing is exceedingly rare. It does happen, but only under extreme conditions or use (often situations in which a chain would have given up much earlier). Meanwhile, ebike chains are more prone to failure with mid-drive motors due to the high torque placed on them relative to a regular bike.

Durability aside, belt drives are almost completely silent, feel extra smooth while pedaling, require no lubrication, and won’t get grease on your pants. The only maintenance required is keeping the belt clear of too much debris and the occasional tensioning, which is easy to do at home (and involves strumming the belt like a guitar).

Plus, they just look pretty cool, if you ask me.

What’s the catch?

There are two big caveats to using a belt drive.

The most notable one is that belts are incompatible with traditional derailleurs. That means that virtually every belt-drive bike is either a single-speed (which isn’t the biggest deal when you have a motor to help), or uses internal gears.

Usually, belt-drive ebikes that aren’t single-speed use an internally-geared rear hub. That means it’s rare to find belt-drive ebikes that use rear hub motors and have multiple gears, although occasionally you’ll get bikes with gears closer to the pedals, such as a Pinion Gearbox or Schlumpf Drive. Still, those are the exception to the norm.

Derailleur and chain on Juiced CCX