You’ll occasionally hear cyclists make extravagant claims about the interaction between gears and hills. “With proper gearing, climbing is just as easy as riding on flat ground,” they say. These statements aren’t quite true, but there’s a big nugget of truth hidden in the exaggerated claim.
How many speeds should your bike have to rocket up hills with ease?
Most 7- or more speed bikes with 700c wheels are suited for climbing hills, however, more important than the number of gears is the gear ratio of the lowest gear. Low gear ratios provide more torque which riders need the most when climbing up hills.
Let’s talk about gear ratios, bike gearing, and why the raw number of gears on your bike might not matter as much as you think it does.
About Gear Ratios
If you’ve got a bike with the right gear ratio for your ride, you’ll be able to maintain the same cadence and level of effort the whole time, even on steep hills. This means you can pedal at a comfortable pace without standing up while still progressing on any terrain.
So how does this work? Can you do this on any bike?
Your bike uses a front cog (called the chainring) to turn a rear cog (the collection of cogs is called a freewheel or cassette) via a linked chain. These cogs behave exactly like any gears that you encounter in an engine or other mechanical device.
This means that if the cogs are the same size, rotating the front cog once will rotate the rear cog once. On the other hand, if the front cog is twice as big as the rear cog, rotating the front cog once will spin the rear wheel two times.
While varying the relationship between the cogs will change the number of times the rear wheel spins each time you rotate the pedals, It takes the same amount of force to spin the rear wheel once.
This means that doubling the size of your front chainring will require twice as much power from your legs for each rotation.
On the flip side, doubling the size of your rear cog (or halving the size of your chainring) will require half as much power from your legs. You’ll go slower, but each pedal rotation will be much easier.
Calculating the exact gear ratio of your bike is pretty simple. All you need to do is count the number of teeth on your largest and smallest cogs at each end. If you’ve got a set of front chainrings with 36 and 22 teeth, for example, and a rear cassette that goes from 12 to 32 teeth, your bike can have a gear ratio between 3 (or 36 divided by 12) and 0.68 (22/32).
When it comes to hills, your gear ratio is important because it lets you multiply the difficulty of pedaling your bike. Going from a 2.0 to a 1.0 gear ratio makes pedaling twice as easy. Since pedaling against gravity gets a lot harder, lowering your gear ratio to compensate will let you output a constant level of effort while keeping your bike moving.
Does the Number of Gears (speeds) Matter When Going Uphill?
The number of speeds your bicycle has doesn’t matter when going uphill — technically. Changing gears on a bike gives you a selection of different gear ratios, as mentioned above. This means that the easiest speed on a bike is dictated by the size of the biggest cog in the back and the smallest chainring in the front.
It doesn’t matter how many other gears your bike has since you can only use one at a time. If the cogs are the same size, a 6-speed and a 12-speed will pedal the exact same.
There are two big advantages to having more speeds on your bike. First, bikes with more gears give you more “in-between” options, allowing you to select a speed that perfectly matches your desired cadence.
While a 1×6 and a 1×12 that go from 12 to 32 teeth will have the same biggest and smallest gear ranges, you’ve got twice as many options in the 1×12 setup. This means it’s much easier to dial in the right gear for each section of a hill.
Secondly, bikes with more gears tend to have bigger gear ranges overall. The more cogs your bike has, the bigger the difference between the lowest and highest gear can be without making each in-between step gigantic.
Modern 1×12 drivetrains take advantage of this to run 50+ tooth cogs, which would be difficult and unwieldy on drivetrains with only 6 speeds or 8 speeds in the back.
What Makes a Bike Good for Climbing? (gear-wise)
Generally speaking, high gear ratios are ideal for going really fast, while low gear ratios make it easier to pedal your bike uphill or into a headwind. The exact gear ratio you’ll want will depend on how steep your hill is, your level of fitness, and how much you’re willing to work.
In general, having a big cog in the back and a small chainring in the front will make climbing hills a lot easier. Luckily, both of these parts are pretty easy to replace. The trick here is to make sure that anything you get is compatible with your whole drivetrain.
9, 10, 11, and 12-speed bicycles use different-sized chains that have special cog requirements, so you’ll have to be extra careful with anything you put in the back. Front chainrings don’t have quite the same compatibility requirements, but it’s still a good idea to do some research on your manufacturer’s recommendations before you buy anything.
What Other Factors Make My Bike Good For Climbing?
A light bike with low rolling resistance will conquer climbs with less effort than a heavy bike with lots of drag. Make sure your tires are inflated, use the skinniest tires you can get away with, and make sure that your derailleurs and brakes have been tuned up recently and that your wheels are true. These little maintenance checks can put a big dent in how easy it is to keep your bike rolling up a long hill.
As far as features go, consider your frame geometry and handlebar setup when choosing a bike for climbing. Climbing is about endurance more than aerodynamics, so be sure to use a bike that you can ride comfortably for long periods.
Ideally, your bike will keep your weight far enough forward to keep the front wheel down while seated comfortably, which means you’ll want a somewhat steep seat tube angle. If you have to lean forward while climbing, your arms might become fatigued and you’ll likely find yourself worn out far sooner than if you had chosen a bike with better geometry for climbing.
Do I Need to Have a Front Derailleur To Climb Up Hills?
There’s a growing trend in higher-end modern bikes to use a setup with a single front chainring and a LOT of gears on the rear cassette. These bikes tend to climb hills totally fine. For one, this trend is most prevalent in mountain bikes.
Mountain bike drivetrains are usually designed with climbing difficult terrain in mind, so they’ll have some super low, torquey gears that make climbing a breeze.
While 2x or 3x setups offer more gear ratios to choose from, the total difference might surprise you. There’s a big band of overlap between the two chainrings, meaning that a 2x setup often only gives you four or five more effective gears.
A high-end 1×11 or 1×12 setup can actually have a bigger overall gear range than a 2×8 or even a 3×8. In other words, worry about the ratios, not the number of total gears.
If I Ride On Hilly And Flat Terrain, How Many Speeds Should My Bike Have?
An ideal bicycle will have a high gear that enables you to put your legs to work on long sections of flat road and downhill runs, while also giving you a low gear that lets you relax and pedal comfortably up the steepest hill on your route.
As mentioned above, there’s no magic number of speeds that will guarantee that a bike will have the right ratios. You can, however, use a few quick rules of thumb to try to figure things out.
3-speed bikes often have planetary gearboxes or other hub gears that allow the bike to change how your pedal power is applied within your rear hub. These bikes tend to have narrower gear ratios than bikes with derailleurs and may lose a bit more power due to the complex operation of the gearbox.
3-speed bikes are pretty uncommon, but they’re usually best for city riding with fairly uniform terrain.
Bikes with 3 front chainrings, or 3-by drivetrains, are usually entry-level mountain bikes or hybrids. These bikes tend to have plenty of options for casual cyclists. You might find your options are a bit lacking on one end, however.
Bikes with 6, 7, and 8 speeds in the back also tend to be entry-level models. There’s nothing wrong with this, but it does mean that you’ll see fairly tame cog setups that don’t have the incredibly small or large cogs that you need to get an outlandish gear ratio. You’ll usually see these bikes with 2 or 3 chainrings in the front, although this may vary.
Bikes with 9, 10, 11, or 12 speeds start to use some pretty serious (and expensive) components. The more cogs your rear cassette has, the more complicated and delicate it gets. The good news here is that these complicated and delicate systems can handle ridiculous cogs.
1×12 setups can be found in 11-52 configurations, which is nuts. The easiest cog is 4.72 times easier to pedal than the hardest cog. This is a bigger difference than some 3x systems. If you’re after a bike with a bigger variety of gear ranges, look for a bike with 9, 10, 11, or 12 speeds in the back.
As far as front derailleurs go, 1x systems are cool but not necessary. While there are some definite advantages in terms of frame design and reduced complexity from a 1x system, there’s also nothing wrong with having a front derailleur.
If a 2x or 3x system works with your frame, be sure to check out all of your available options. Don’t forget to check the actual gear ratios, too. Some 2×9 drivetrains can hit the same gear ratios that a super fancy 1×12 system can hit while giving you more gears overall, but others might not have the right size chainrings out of the box for your hill-climbing needs.