How to Change Gears on a Bike Like an Expert
Very few places that you ride your bike will be perfectly flat so when the gradient changes then correct use of your bicycle’s gears will ensure that you have a smooth and comfortable ride. In this guide, we will explain the theory behind changing your gears and share some essential tips to make sure your bike runs efficiently whilst going up and down the sprockets. By the end of this article, you will know how to change gears on a bike like an expert, even if you’re only getting started in the world of cycling.
What Do I Need for This Tutorial?
Simply put, the only thing you will need is a bike with multiple gears! This tutorial does not require any specialist tools or equipment, but as general advice, your bicycle drivetrain should always be well maintained and regularly serviced by somebody with a good knowledge of bicycle mechanics. A well looked the set of gears will be your best friend when out riding but poorly maintained gears can be frustrating and distract you from your ride.
Cassettes and Chainrings, What is the Difference?
On the vast majority of bikes, the gears comprise of chainrings connected to the crank (between 1 and 3) and multiple cassette sprockets connected to the rear hub in a cluster (ranging from 6 to 11 sprockets).
A Cluster of 9 Cassette Sprockets on a Rear Wheel
A "Double" Chainset with 2 Chainrings
These two sets of gear wheels are connected by the chain and by selecting different combinations of chainrings and sprockets it is possible to vary the gear ratio of your bike. The table below shows the number of total gears available with different chainring and cassette sprocket combinations.
Number of Cassette Sprockets
|No of Chainrings||6||7||8||9||10||11|
So do more gears mean a better bike? Well not necessarily, as ever it depends on the type of terrain and style of riding you are tackling. For very hilly areas where you will be riding up and down steep gradients, a wide range of gears will help you manage your efforts accordingly, but a higher number of gears usually means extra weight (more sprockets) and more attention required in indexing your gears, so if you are riding predominantly flat terrain then a smaller range of gearing can be a wise choice.
There are also certain applications such as downhill mountain biking where the security of staying on one chainring and hence reducing the likelihood of a dropped chain, outweighs the benefit of more gears.
What Size Sprockets and Chainrings do I Need?
It’s no good having a plethora of gear ratios if none of them is suitable for the type of cycling you’re doing, see below for the typical sprocket and chainring sizes for road and mountain bikes;
- Road Bikes - The traditional chainring setup for road bikes is a double setup with 39 and 53 tooth rings but triple chainsets are also common with the addition of a 30 tooth ring for steep climbs. In recent years the “compact” chainset has gained popularity, this is a 50, 34 tooth combination which gives a slightly wider range of gearing than traditional setups. Specialist time trial bikes built for absolute top speeds sometimes feature chainrings up to 60 teeth in size but these are specialist items and not usual. On the rear wheel, 9, 10 and 11 cogs are the most common configurations with the majority of cassettes covering a range of 12 to 25 tooth cogs. Gearing designed specifically for racing sometimes have a smallest cog of 11 teeth, and cassettes specifically designed for climbing sometimes feature bottom gears of up to 29 teeth.
- Mountain Bikes - The slower speeds experienced in MTBing require much smaller gear ratios than road bikes, chainring sizes typically range from 28-40 which isn’t too different to road gearing, but MTB cassettes feature largest sprockets of up to 40 teeth which give significantly smaller ratios for steep climbing on loose ground. Smallest cassette cogs are as small as 11 or 12 to provide downhill speed meaning that generally there are bigger changes in the resulting ratio when changing gear on a MTB.
A MTB Cassette features much bigger 'large' sprockets compared to the road equivalent
So How Do I Change my Gears? The Operation of Shifters
With modern bicycle components, it’s not always obvious at first glance how you operate gear shifters with paddles and levers being seamlessly integrated into your brake levers so here are the most popular systems on the market currently and an overview of how they operate:
Shimano STI (Mechanical)
Shimano shifters with cable operated gears are the most common offering on road bikes. Each lever has two shifting movements; by moving the entire brake lever sideways (inwards) cable tension is increased. For the right-hand shifter this makes the chain move to a smaller cog on the rear cassette (easier gear), on the left-hand shifter, this results in the chain moving to a larger chainring (harder gear).The second movement is achieved by pushing the small paddle behind the brake lever sideways only. This decreases the cable tension which, on the right-hand shifter moves the chain to a smaller cog on the rear cassette (harder gear) and on the left-hand shifter moves the chain to a smaller chainring (easier gear).
Shimano STI (Electronic)
The electronic range of Shimano road shifters (Di2) operate slightly differently by having two buttons on the outer face of the shifter and no sideways movement of the brake lever.
On the right-hand shifter the textured button (closest to brake lever) shifts to a larger sprocket on the rear cassette and the smooth button shifts to a smaller sprocket on the rear cassette. For the left-hand lever, the textured button moves the chain to a larger chainring and the smooth button moves the chain to a smaller chainring.
SRAM Road Shifters
SRAM are the newest big player in the road drivetrain market and they entered the ring with a revolutionary double-tap shifter design. It features a single, sideways moving paddle behind the brake lever with a two-stage mechanism. A small sideways movement results in decreased cable tension which, on the right-hand lever moves the chain to a smaller cassette cog and on the left-hand lever moves the chain to a smaller chainring. Conversely, a large sideways movement increase the cable tension which moves the chain to a larger cassette cog on the right-hand lever and on the left-hand lever moves the chain to a larger chainring.
Mountain Bike Gear Shifters
The vast majority of mountain bikes have ‘trigger shifters’ which consist of a thumb operated lever below the handlebar and an index-finger operated trigger above the handlebar. With these type of shifters the thumb levers increase cable tension (shifting to an easier gear on the right hand lever and a harder gear on the left hand lever) and the index-finger operated trigger reduces the cable tension (shifting to a harder gear on the right-hand lever and an easier gear on the left-hand lever).
Another type of MTB shifter is the 'Gripshift' design which achieves varying levels of cable tension by rotating a portion of the handlebar forwards and backwards with your wrist. This can be an easier method of changing gear in cold conditions where thick gloves make it harder for you to pick out small levers and paddles with your fingers. In most cases twisting the shifter back towards you increases the cable tension and rotating forwards away from you reduces the cable tension.
Putting it Into Practice:
So now that you know how to operate your gears, when should you be shifting and how often? Below are the essential tips you should know to ensure smooth and efficient use of all the gears on your bike:
- Look at the terrain ahead of you and try to anticipate any gradients that will require a gear change. In general, it is always better to change into an easier gear before a steep hill as this will help you to conserve your momentum as you begin climbing.
- Don’t forget that hills are not the only obstacles that require gear changes, strong winds will affect your effort and subsequent speed just as much so think about which way the wind is blowing, especially if you are about to change direction.
- In order for your gears to shift your chain must be moving forwards. Make sure you are always pedalling when you shift and never try to shift your gears when your bike is stationary.
- If you do a lot of riding in built-up areas, remember to change to an easier gear before stopping at a traffic light. Trying to pull away in a gear that is too big is very hard work and can be dangerous with other road users around you.
- Don’t shift gears under heavy load. This is again about changing into an easier gear before you need to on a steep hill. If you wait until it is very hard work to turn the pedals before shifting down then there is an increased chance that your gears will slip, causing a sudden jerk in the pedals. This is especially likely if you try to shift gears when standing up out of the saddle and in some cases could cause you to lose your balance.
- Your preferred cadence (the revolutions per minute of your pedals) is individual to each rider, but generally, your legs are most efficient in the range of 70 to 100 revolutions per minute. Try and use your gears to keep your cadence within this range at all times.
- Keep your drivetrain clean from debris and well lubricated. The chain is the only component that should need oiling but all cogs and other drivetrain components should be kept as clean as possible to ensure crisp and reliable shifting.
- Regular maintenance is essential - Adjusting the cable tension in between your shifters and derailleurs (indexing) is something that should be checked every 500 miles or so to ensure your gears change quickly and cleanly.
- Avoid Cross-Chaining: Cross-Chaining refers to using combinations of gears that result in your chain running at extreme angles. There are three main downsides to this practice:
- An extreme chain angle increases the risk of gears slipping
- The further away from straight your chain is, the less efficiently it transfers power to your wheels.
- Large chain angles increase the rate at which your chain, chainrings and cassette cogs wear, which means they will need replacing more often.
Cross chaining occurs when you use the smallest chainrings along with the smallest cassette cogs, and the largest chainrings along with the largest cassette cogs as shown in the diagram below.
As we have seen, there are a plethora of gear shifting systems, and gear sizes available to suit all riding styles. By following the tips advice you will be able to master your own gears and make sure they enable you to enjoy riding over all manners of terrain.
As manufacturers continue to develop new and improved gear shifting systems the way we change gears on our bikes is always changing. Have you used a system different to those mentioned above or have you seen a different system and are wanting more in depth information? If so please leave us a comment.
Do you have any other tips for changing gears on your bike from your own experience? If so please let us know in the comments section.
We also have a related article called How to change bike pedals that covers everything needed for changing bike pedals.