I've been riding belt-drive bikes across continents since 2010, and after more
than 100 thousand kilometres across 100 countries, I'm ready to tell you there is
no better touring, bikepacking or commuting drivetrain available. I've
taken belts across the hottest deserts, into icy snowfields, through dense
jungles, along beaches, up muddy tracks and to the top of the highest road in
the world. I suspect there are few people on Earth with the same real-world
experience as me. In this video, we'll look at what belt drive is, what the
advantages and disadvantages are, and then I'll go through the frequently
asked questions to make sure no rock is left unturned.
Oh, and this is not a sponsored video, I haven't invested in any belt drive
businesses and I am free to use chains on my bikes at any time. I'm just a big
old fan of belts and I hope you can soon see why. So, what is belt drive? Belts are
used to run the blowers on 10,000 horsepower racing engines, the power
trains of 150 horsepower motorbikes and more recently the drive trains of many
bicycles. Gates Corporation invented their first automotive bolts about a
century ago, and today, they're the most popular brand of belt system for bikes.
The belts themselves are made from a polymer that is reinforced using
multiple carbon-fiber cords. They are then usually paired with stainless steel
cogs and durable alloy chain rings. And why do I think belts are the best
drivetrain? Number one, belts have a very long service life. You can expect a belt
drivetrain to last three to four times longer than a typical chain. That's
upwards of 30,000 kilometers, even in the poor riding conditions you often see me
flailing about in! Additionally, they're impervious to water and salt, so there's
no rust here, even after months of cycling through intense wet seasons.
Number two, belts require little to no maintenance. Belts do not stretch, they do
not require lubrication, they are never greasy and they do a
surprisingly good job of clearing the mud.
Just a splash of water is usually enough to keep them going.
Number three, belt drive trains are perfectly silent. You know when your
chain is freshly cleaned and lubed and running perfectly silent? Well, that's
about pretty much all of the time! Number four,
belts are lighter than chains. You can expect a weight saving of between 100
and 300 grams when compared to chain drive. The upsides are looking pretty
darn good, but what about the downsides? Number one, you cannot use belt drive
with derailleurs. A belt is designed to run in a perfectly straight line. That means
it cannot be paired with derailleurs, chain rings or cassettes, but it can be used
with a gearbox at the crankset or an internal gear hub at the rear wheel.
Number two, you need a belt compatible frame! As belts are usually one-piece, your
frame will need to be designed with a belt splitter in the rear triangle so
that you can fit a belt to your bike. The frame also needs to be 'stiffness test
approved' to ensure that the frame will not flex sideways too far,
causing the belt to wander off the rear cog. Number three, replacement parts and
not found in typical bike shops. I personally have never found this to be a
problem, I buy all of my spare parts online and I always carry a spare belt
for emergencies. I usually travel for 18 months before I even start thinking
about ordering replacement parts. Number four, there's a higher upfront cost. A
belt drivetrain is not super cheap, but they are cost-efficient provided you get
the full mileage out of your belt drivetrain. I've estimated you'll go 125
kilometres per dollar. This is the equivalent of a chain drivetrain costing
you about $60 per 7500 kilometres. For reference, that's the same price as the
longest-lasting chain we have, which wears out at between 5,000 and 7,000
kilometres. And number 5, it's a less efficient drivetrain. Derailleurs are
undoubtedly the most efficient drive trains available with an average drive
efficiency across all gears of between 95 and 98
percent. As you need to employ a gearbox system on a belted bike, there will
always be additional frictional losses. According to the data we have, Shimano
internal gear hubs and Pinion gearboxes are a bit over 90 percent efficient,
while the Rohloff hub jumps to over 94 percent efficient.
The efficiency discrepancy is one of the reasons you rarely see gearbox and belt
drivetrains on race bikes. There can be additional resistance at the belt too,
but it's a much smaller percentage than the gearbox itself. Let's move on to all
of the frequently asked questions you might have about belt drivetrains.
How does Gates Carbon Drive feel to ride? It rides just like a well-lubricated
chain, but it has a slightly different humming sound. And, despite its looks, it
feels just as stiff and solid to ride as a chain. How do you repair a belt? It's
very easy to remove a chain link on the side of a trail. Belts on the other hand
are designed to be replaced. Rather than carrying a chain tool, it's prudent to
carry a spare belt which coils down into a small enough size. I've broken just 31
thousand kilometre old belt in the last 10 years, so emergency belt replacement
never actually crosses my mind. When do you know a belt is too worn? Surprisingly, it's
the rear cog that wears the fastest on a belt drivetrain, the teeth can get very,
very pointy! Given that I stray pretty far from services
I usually swapped my entire drivetrain out as a precautionary measure at about
30,000 kilometres. I've never actually found the true distance limit where the
belts cease to work, but it looks like the lifespan may have just been extended
as Gates has just introduced a new high-hardness steel cog this week! What's the
deal with belt resistance? Perhaps you've seen videos of people stacking weights
on pedals to show the difference in drive resistance between a belt and a
chain. These tests are a bit misleading because chain and belt friction
increases at different rates - the belt slope is actually four times less steep.
There is a crossover point where a belt becomes more efficient than a chain, it's
when you're pedalling at two hundred and twelve watts. This is a bit
higher than the typical cyclist pushes, so expect around half a watt penalty on
the belt system in ideal riding conditions, but likely a better
efficiency in adverse conditions due to the way a belt can remove debris from
the cogs. That said, if you use a particularly stiff frame, you can lower
the belt tension below the recommendation. You didn't hear this from
me, but I've been slowly reducing the belt tension on my Koga over the last
year, and frankly, it's getting ridiculous. My belt can now touch my chainstay, it is
so far beyond the minimum that I can't even measure it! And I'm a very strong
rider, with a very heavy load, riding up incredibly steep mountain roads. At my
approximate belt tension and at the power outputs I push, my belt is likely
running the same or lower friction than a chain. I only recommend trying this
with a belt snubber fitted which will make sure the belt stays on, even if the
belt tries to skip. So, what is the actual maintenance like? If you ride in adverse
conditions, it's a great idea to use a toothbrush and water to clean any debris
off the system - if only to reduce the wear on your cogs. In dry conditions with
very fine dust, a belt drivetrain can sometimes make an infuriating squeaking
sound. This is very easily remedied by using a silicone spray which immediately
dries onto your belt. I am currently experimenting with
treadmill silicone lubricant which stays wet a bit longer, attracting more grit in
the short term, but it seems to require fewer applications. Rohloff
biodegradable chain lube is known to work similarly. Just make sure to skip
the Hanseline belt care stick, it's extremely sticky, and frankly, a terrible
product for a belt. How do you adjust the belt tension?
Unlike chains, belts do not get longer over time, resulting in a true
set-and-forget drivetrain. There are two typical ways to set the tension of a belt.
Some bikes use sliding rear dropouts, but from speaking to a handful of bike
engineers, it sounds like an eccentric bottom
bracket shell allows for the stiffest possible rear triangle for running the
lowest possible belt tension. You can use your smartphone to
appropriately determine the tension of your belts. By plucking the belt, your
smartphone app will decipher the tension frequency and determine if your belt
tension is correct. As you can see, my belt falls below the frequency range. But
if we tension everything up, we can get a reading.
Don't belts destroy bearings? It's possible that a belted bike with the
maximum belt tension could prematurely wear bearings. But on a bike engineered
for belts, the frame will be stiff enough so that the tension is the equivalent of
a rider using a chain and pedalling at 250 watts, which is not at all that
unusual. Aren't there limited gear ratios
available? There are four rear cog sizes, there are four sprocket sizes and there
are twenty belt lengths to choose from. This should not at all be limiting for
the purposes of touring and commuting. Can you modify a frame for belt drive? I
have taken two touring frames to a custom frame builder to get rear belt splits
installed in the rear triangles. They have worked just fine but I've had to
use a high belt tension as the rear triangles had more side-to-side flex
than a dedicated belted frame. Are there any other belt companies? Gates
completely dominate the market when it comes to belt drivetrains, but there are
a few manufacturers offering alternatives, including Veer, Accord and
Driveline. Veer looks to be the most promising and has one big advantage over
Gates - their belts are able to split, which means that you can fit them to any
bike! As the rear triangles of a typical bike and not designed to be particularly
stiff, I suspect the Veer system will have a
high friction when retrofitted to a bike. But that said, you still get all the
advantages of belt drive, so I think it's a really cool product if your belt
curious and don't want an entirely new bike. Let's wrap this up!
I hope this information has hit every possible belt talking point. I have put
belt drivetrains through the wringer for 10 years, taking them into the
world's most remote locations, and I'm certain there is no better drivetrain
available for touring, bikepacking and commuting. If the idea of a gearbox
system like the Rohloff or Pinion is compelling to you, definitely
skip the chain option and pair it with belt drive. They are incredibly
long-lasting, virtually maintenance-free, lightweight and silent to ride. You can
support this content over on Patreon, you can follow me
@cyclingabout on Instagram and Facebook, check out the Bikepacking Bike Buyer's
Guide and the Touring Bicycle Buyer's Guide, learn cool shit on CyclingAbout.com,
leave a comment below, and here's a challenge - try and convince me that chains
are better than belts!