Who would not want to spend more time riding their bike and less time adjusting and cleaning it?
Belt drives promise to make them happen, and we’ve seen several more belt-drive offerings on the market in recent years.
But are they just passing novelty, or are belt-drive bikes worth buying?
After proper set-up, belt drives require almost no regular maintenance and often last 20,000 miles or more (about 10x longer than a chain). They rinse clean with water and have no exposed grease to stain your clothes. However, they’re less mechanically efficient than a chain, they use expensive proprietary cogs, and they require an internally-geared hub for multiple speeds. You generally can’t retrofit a belt onto a chain-drive bike, and options for new belt-drive bikes are very limited to due high prices and limited appeal.
Belt drives a nifty idea and great in principle but it can be hard to figure out whether they’re right for you, so let’s take a closer look at their biggest pros and cons. If a belt drive does seem right for you, then jump over to this list (coming soon!) of excellent belt-equipped bikes that I would personally want.
(Featured photo: the belt-equipped Classic Plus from Priority Bicycles)
What’s the point of a bicycle belt drive?
Tire pressure is the most common maintenance point on a bike. And drivetrain adjustment and lubrication is the second.
Part of that is because chains stretch over time, and part of that is because grit and grime have a sandpaper effect that wears down you chain and gears.
Basic drivetrain maintenance isn’t realistically that big of a deal, but minimizing does stand to save you some time and hassle–especially in harsh weather or gritty conditions.
A belt drive uses something kind of like an automotive timing belt to replace the chain. That means it stretches out incredibly slowly, if at all, so you’ll typically get 20,000 miles or more out of a single belt.
Very roughly speaking, belts last ten times as long as a chain, but only cost three or five times as a chain. In that sense, they’re a good deal if you’ll own the bike long enough to reap the savings and you didn’t pay through the nose for the belt drive set-up in the first place. (Still, seeing as a $25 chain can last a year for most of us, I wouldn’t decide based on price alone.)
One of the best aspects of belt drives is more incidental: they don’t use grease. Without pivoting joints or metal-on-metal contact like a chain drive, there’s just no need for it. In fact, the manufacturers deliberately caution you not to lubricate grease the drivetrain. That means your pants stay cleaner, or at least you only get dirt on your pants instead of greasy dirt. It also means you can simply rinse the drivetrain clean.
How does shifting working with a belt drive?
The belt is wide and very stiff, so you can’t just use a derailleur to shift it onto another cog for changing gears. It has exactly one chainring in the front and one cog in the back, whereas a chain permits up to three in front and anywhere from 7-12 in back.
So, how do you get multiple speeds? Well, you can run it as a single-speed, of course, but the more common approach is to shift with an internally-geared hub, or “IGH” for short. An IGH replaces a derailleur entirely, since it contains all the gears and shifting mechanisms inside of the weatherproof rear hub.
Note that internally-geared hubs are common options with a chain drive, but they’re necessary with a belt drive assuming you want more than one speed.
One small disadvantage of internally-geared hubs is some have only a narrow gear range. Three-speed IGHs are very common, especially at lower price points, and that’s sufficient for flat terrain or rolling hills. On steeper hills, they’re still rideable, but you may have to work harder than you’d like to.
Above entry-level prices, you’ll find 7-speed or more often 8-speed IGHs. Those do in fact get close to the range of gears on a typical chain drive. The steps in between gears are larger, but the ratio of your highest to lowest will be similar.
Finally, there are 11- and 14-speed IGHs, and even some continuously-variable ones, with a wider range yet.
Whatever the IGH’s gear range, it’s all relative to the chainring and cogs. Those are effectively a baseline gear from which the hub will shift up and down a certain amount.
And that leads to one very important caveat…
What if I don’t like the gear range?
With an internally-geared hub on a chain drive, it’s cheap and quick to replace the front chainring or rear cog with larger or smaller ones. That effectively moves the entire gear range up or down to your liking.
With an IGH on a belt drive, that’s very expensive since: a) the cogs themselves are pricey and b) it may require a new belt of a different length, since you can’t shorten or splice a belt like you can a chain. Depending on the exact parts, sizes, and mounting styles, it’s easily a $200+ project.
So, you may wonder, is there any way to know how many speeds you need?
Well, it requires a little guesswork, but you can actually get a very good idea by trying a chain-drive bike on the routes you’ll normally ride. If you find yourself in need of the very lowest gears, then you’ll want at least an 8-speed IGH for your new belt-drive bike. Conversely, if you never need to go more than one or two gears below the very middle of the range, then a 3-speed IGH should easily suffice.
This test is pretty simplistic, but it’s a reasonably accurate way to figure what gear range you actually need. And given the pricing of changing that after the fact, it’s worth going to a little more trouble up front.
Pro tip: if you don’t mind geeking out on this a little, then it actually is possible to know whether the gear range will really work for you. The key is to use a gear-inches calculator like this one from the late Sheldon Brown, a legendary mechanic and writer. It tells you exactly how far the wheels rotate for each turn of the cranks, and that in turn tells you how “hard” a gear is. Crank length does make a slight difference, but generally speaking, the same gear-inches number means the gear feels about the same.
Simply run the calculator using the exact gearing on a bike you’re familiar with, then repeat with the belt drive’s sprocket teeth and IGH, and you’ll cut out the guesswork altogether.
How do belt drives feel?
You won’t notice a night-and-day difference the first time you hop on a belt-drive bike. It’s very quiet, and sometimes you can feel just a hint of the very large teeth engaging, but those things aren’t a big factor in the riding experience.
There is a small but noticeable increase in pedaling resistance. During laid-back riding–thinking cruising in the park–it might feel like a very slight headwind. But as you ride harder, that resistance becomes trivial relative to the power you’re putting out, so you more or less cease to notice it.
However, the internally-geared hub (remember, that’s necessary for multiple speeds) adds its own mechanical inefficiency beyond a well-maintained derailleur. You can feel it equally during gentle and hard riding, but the magnitude depends on the hub model and the specific gear you’re in.
What kind of maintenance does it require?
It’s critical to set the belt tension properly before your first ride. Otherwise, whether too loose or too tight, it will wear out prematurely and get nowhere near the phenomenal lifespan you’d expect.
Assuming you’re using a Gates Carbon Drive belt (the industry standard), the Gates smartphone app makes it easy. Here’s a great demonstration of the process:
How you actually adjust the tension will depend on your bike’s frame. The example video shows adjustment with an eccentric (elliptical) bottom bracket, but many bikes have horizontal or diagonal rear dropouts instead.
In principle, you should never need to repeat this process during the lifespan of the belt. One hopes it will arrive from the seller with the proper tension in the first place, but it’s worthwhile (and surprisingly fun) to double-check with the app.
Interestingly, some reports like in this StackExchange discussion say that belt tension changes with temperature.
In my personal experience, commuting through hot and cold seasons with a belt drive, that was not the case. One single, initial adjustment lasted until I sold the bike. But your experience may vary, so initially tensioning it in slightly cooler weather seems like a reasonable precaution.
Don’t forget to maintain the IGH!
On a belt-drive bike, it’s not actually the belt itself but the internally-geared hub that needs more hands-on attention (if only rarely).
First off, the hub will require cable tension adjustment on occasion. In my experience, it’s infrequent: in the realm of a couple times a year. And it doesn’t matter much, because it only takes a few second anyhow.
(Most hubs have some sort of visual indicator that you should periodically check. Details depend on the manufacturer and model, so the manual will tell you what to look for and how to adjust the cable in response.)
The IGH will eventually need service. It’s usually once every couple of years, but mileage is the biggest factor, so follow the manufacturer’s recommendations to the letter.
Servicing an internally-geared hub can be complicated, so it’s best reserved for professional mechanics or more intrepid amateurs. IGHs aren’t as popular on North American city bikes as on European ones, so it’s possible that your local shop would prefer not to work on it–although most should be perfectly willing and able.
Can’t I just put a belt drive on my current bike?
You cannot simply upgrade a chain drive bicycle to a belt drive. That’s because the frame has to be specially designed for it.
The way you install a chain in the first place is by separating one of its links, looping it around the chainstay, and then reconnecting it.
But belts don’t separate (which is part of why they’re so durable).
That means the seatstay itself needs to separate so the belt can pass through. A sturdy but separable joint requires more engineering and testing, so it’s simply not a standard feature. Manufacturers don’t build it unless they’re specifically designing the frame to be belt drive-compatible.
And there’s one more critical criterion. To get the right belt tension (see the video above), you need an eccentric bottom bracket or horizontal/diagonal dropouts. The latter are common on vintage bikes and modern single-speed and IGH bikes, but most bikes with a derailleur have neither.
A simple alternative for bikes without derailleurs
If your bike has a single speed or an internally-geared hub, then a full chain case will get you close to a belt drive’s cleanliness. Dutch-style metal chain cases are extremely effective, but also heavy, complicated to install, and arguably a little ugly.
A lighter and simpler alternative is the Hebie Chainglider (available here). It slides into places on top of the chain, so a bit of friction is theoretically possible, but shouldn’t be a problem.
Again, you must have a single speed or IGH, since neither the Chainglider nor a traditional, full chain case will fit a derailleur.
What about universal belt drive kits?
More recently, companies like Veer Cycle have introduced separable belts that get around (literally) the need for a split seatstay.
Unlike the standard Gates belt, I have not ridden Veer’s firsthand and reviews are practically nonexistent as of writing. But the tiny bit of early feedback I could find (as in this Reddit discussion) is positive.
But just because it’s compatible doesn’t mean it’s cheap. Remember: the belt itself is just one part of the system, which means you’ll need a special chainring (the front gear), cog (the rear gear), and perhaps adapters and horizontal spacers for certain chainring and crank combinations. All told, the Veer upgrade is a roughly $350-$400 endeavor, which is most of the cost of a complete, entry-level belt-drive bicycle.
There’s also some risk with a small, upstart brand. While I’d love to see Veer do well and stick around for many years to come, it seems wise at least to stock up on spares…
Perhaps most importantly, I should reiterate that you’re completely out of luck without an eccentric bottom bracket or horizontal/diagonal dropouts. Unfortunately, that’s something no aftermarket upgrade can change.
Bottom line: is a belt drive worth it for your bike?
When all is said and done, a belt drive drastically limits your choice of bikes. And seeing as chains and derailleurs have gotten us around just fine for over a century…well, if it ain’t broke, don’t fix it.
In practice, the major disadvantage is slight but noticeable pedaling resistance, especially during gentler riding.
But there’s no question that belts are far more durable and far lower in maintenance. If day-to-day drivetrain maintenance feels like an irritating waste of time, then a belt drive will pretty much scratch that off your list
They’re also delightfully clean to handle, although a good chainguard can be equally effective at protecting your pants.
While these parts are very expensive up front, they can last an extremely long time: usually up to tens of thousands of miles with nearly no maintenance whatsoever.
And if that sounds like a good choice on balance, then you’ll be glad to know that a few brands are finally making them available on complete bikes at surprisingly accessible prices. Stay tuned for my upcoming round-up of the best belt drive bikes around right now.
Meanwhile, you can also check visit the Gates Carbon Drive website for their list of almost every belt-drive bike and belt-compatible frame on the market.