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Looking to find out what’s the best gear ratio for either climbing or descending hills on your road bike? Here’s the short answer…
Lower bike gears are the most suitable when climbing up a steep hill. Shift your chain on a smaller chainring and a bigger cog on the rear cassette. The best bike gear for riding down a steep surface is achieved by shifting the chain on a bigger chainring and a smaller cassette cog.
There’s quite a lot of nuance involved in selecting the right gears for any given climb or descent. In this post, I’ll take a look at the best options for going uphill, the best for downhill, and all the other facts you need to know about gears on a road bike.
Basics of Gears
Gears are controlled by shifters that are attached to the handlebar next to the brakes. Usually, the right shifter controls the chain setting on the rear cassette, while the left shifter is used to shift the chain between chainrings.
You can easily remember using the “right rear” alliteration. Some bikes may have only one shifter, as there is only one chainring in them.
Each time you shift the bike chain on cassette cogs or chainrings, new gear is achieved.
The total number of gears in a bike can be calculated by multiplying the number of cogs on the cassette with the number of cogs on the chainring.
For example, if a bike has 7 cogs on the cassette and 3 chainrings, by multiplying 7 and 3, we get 21 which is the number of total gears on that bike.
Normally, the number of chainrings in a standard bike is three. But bikes with two chainrings can also be found very easily.
The two most common types of chainring sets are compact and standard. The first one is suitable for climbing hills, and the latter is better for achieving high speed.
This is because compact chainrings have fewer teeth on their cogs, whereas standard chainrings have bigger rings with more teeth.
Cassette is a term used for the whole set of sprockets on the rear wheel. The number of cassette sprockets is always more than chainrings. Usually, hill climbing road bikes come with 7-12 cog cassettes.
The smaller the cog, the harder the gear will be, and you will exert more energy to pedal.
What is Gear Ratio?
When new riders are starting, they are bombarded with different gear numbers and combinations that they do not understand, leading them to utter confusion. It is easier to understand this phenomenon with the help of gear ratios.
The gear ratio represents the relationship between the number of cogs on both gears, i.e., cassette sprocket and chainring. If you divide the number of teeth on the active chainring by the number of teeth on the active cassette cog, you get the gear ratio.
For example, if your bike chain is set on a chainring with 50 teeth and a cassette cog with 25 teeth, dividing the number of teeth on the chainring (50) by the number of teeth on the cassette cog (25), we get 2.
So, with these rear and front gears, your gear ratio will be 2. In simpler words, the rear tire will make two revolutions for every complete spin of the crank arm.
Similarly, if the chain is shifted to 36 teeth chainring with a 12 teeth sprocket on cassette, the gear ratio will be 3, and the rear tire will turn three times with every complete pedal.
Or, when the active chainring and the active cassette cog, both, have 36 teeth, the gear ratio will be 1.
You will realize that some gear combinations result in the same gear ratio. Like, for gear combinations 32t/16t and 50t/25t, the gear ratio will be the same, i.e., 2.
This phenomenon is called gear lapping. Gear lapping is very common among bikes with many gear options.
Best Gears for Climbing Up a Hill
Now that you have gone through the working and functioning of gears in-depth, it will be easier to pick the right gear for riding up a steep surface and understand why certain gear combinations are the most suitable.
If you fail to use a suitable gear combination on your way up to a hill, it can result in a grinding halt. You will not be able to turn the pedal fast enough when the surface becomes steeper. The situation will not only cause you to exert more energy than necessary, but your top speed will also be considerably slower.
The key is to use a lower gear on an uphill track. A lower gear combination is achieved by shifting the front gear onto the smaller chainring and rear gear to a bigger cassette sprocket. (Source)
Riding the bike on a lower gear ratio is easier and requires less energy.
Your legs need to work less to maintain the cadence, as the pedaling resistance reduces when you shift the gears down. Your endurance is more important than strength and power while climbing up a steep hill.
Determining “the best” gear combination that suits every rider is almost an impossible job, as it depends on various factors like riders’ experience, strength, and cadence.
However, the most common choice among many riders is 48/17.
If you do not enjoy your ride with these gears, you can also go with other popular alternatives, like 49/13, 49/16, 48/16, and 46/16.
If the track is not too steep, and you are riding on smaller and occasional hills, 46/17, 46/18, and 42/17 are good gears.
The gear ratios mentioned above are more fitting as the middle ground for mostly flat trails with occasional hills. These cannot be used for riding up very steep surfaces.
You will need even lower gear ratios for steep hills that are 8% or more. The most preferred gear ratios on such tracks are 50/34, 40/34, 36/40, 34/36, 34/32, 34/30, and 32/20.
However, remember that using gears with such a low ratio will cause you to pedal more, but it will require less effort.
Moreover, your top speed will be much slower, but with good stamina and consistency, you will reach the top without fatiguing yourself.
Best Gears for Riding down A Hill
Riding down a steep hill is a completely different situation than climbing up on it, so the gear ratios or combinations required are also very different.
If you fail to pick an appropriate gear combination, you will end up pedaling with great effort and still not achieve enough speed. And you cannot enjoy your ride down if you are focused on spinning the crank arm.
To ride downhill, you need to go with higher gear ratios to allow you to move faster at a higher speed. The case here is opposite to what I recommended for climbing uphill.
This can be achieved by using the smaller cogs of the cassette combined with bigger chainrings with more teeth.
When riding on with greater gear ratios, you will feel more resistance while pedaling, but the rear tire will complete more rotations with one revolution of the crank arm.
Though your legs will have to put more power, it will increase your top speed.
Like choosing the right low gear ratio for a hill-climbing road bike, the best high gear ratios are subjective and vary from riding to the rider.
But some professional riders prefer to use a bigger chainring set with 53 teeth on the outermost ring to achieve more speed.
Generally, the chainring with 32 to 40 teeth is combined with smaller cassette cogs with about 11 to 20 teeth.
However, the rear cog can go as far as 36 teeth, depending on your strength, cadence, and how steep the surface is.
Although these gear ratios will suit most riders, if you want to go even faster and your legs can endure the extra pressure, you can shift the chain to even bigger chainrings with 50 to 54 teeth.
Hill Climbing Road Bikes
If you ever went to buy a hill-climbing road bike, you must have noticed the wide variety of gear options available on the market. Each bike seems to have a different gear set. New riders, who do not know the purpose and functioning of gears, can get easily confused.
The main role of gears is to make your riding more efficient and enjoyable for you.
To become a professional rider, getting the gears right is one of the most significant things. There are specific gear ratios and gear settings for each purpose.
If your gear is too low, your top speed will be much less, and you will be left behind. Similarly, if your bike gear is too high, you may not be able to pedal fast enough, and you will tire yourself down unnecessarily on your way up a hill.
That is why getting your gear right is crucial to help you save your energy and be efficient.
This article will guide you through everything you need to know about bike gears, their functioning, and the best gear setting for a hill-climbing road bike.
Things to Remember While Riding Uphill
Following are some tips for beginner riders that will help them to improve their performance on steep uphill trails.
Different types of hills require different strategies. You cannot use the same plan for a less steep hill that you used for a sharp slope.
That is why planning your ride ahead and formulating a suitable strategy always helps.
Take an Easy Start
One common mistake most beginner riders make is starting too hard too early. This way, they tire themselves quickly, and their lungs are gasping for air while their legs cannot put up with the effort.
Instead of surging the speed early on, take an easy start so you can use that reserved energy for the hardest part.
Build the Momentum
Building your momentum a little earlier before you start climbing up can make a big difference.
If there is a flat surface, begin pedaling faster a little before the hill comes. You can use this extra momentum instead of putting all the power using your legs.
Similarly, you can use the descending momentum of one hill to climb the next one.
Shift the chain to an easier gear before you start your ride uphill. It will give you a smoother transition, and the chain won’t have to undergo unnecessary pressure.
Sometimes when you cannot manage to move to a lower gear on time, the chain may not shift later on due to high tension.
Breathing is the key.
To keep your heart rate under control, make sure to take deep breaths to supply the maximum amount of oxygen to your lungs.
Maintain a relaxed posture with arms a little bent and shoulders down.
Standing up instead of sitting on your bike while climbing a hill can give you a power boost. You can use your body weight to push the pedal with more power (Source).
It will also give your back and legs a break if they have started aching.
Nothing consumes your energy like riding uphill on a bike. It makes your glycogen deplete very quickly. So make sure to eat up before you hit the ride.
And if you are doing a lot of climbing, you may need to take breaks in between and fuel yourself.
Get Rid of the Extra Load
If you are still facing difficulty while riding upon a steep surface, it can be because of the extra load you are carrying. Get rid of every needless part that makes the bike heavy.
Some bikes are made of lighter materials, designed specifically for hilly terrains. So, make wise decisions when you are purchasing one.
Although climbing up and down hills is always a fun ride, knowledge about gear ratios is necessary. Shifting the bike chain to the right gear combination not only increases the efficiency but also makes your journey more enjoyable.
Use the general rules and keep practicing with different combinations to find the gear ratio that suits you the best.