How Do Bike Gears Work? Find Out Here!

Changing gears on a bicycle can seem like a very demanding task to some, but that couldn?t be any further from the truth. Having the comfort that your bike can handle pretty much any condition that you may encounter is something most cyclists enjoy.

Whether it?s a steep descent or climb, a flat tarmac surface, muddy or gravel trail, knowing how to circumvent such situations with a geared bike may be the difference between a few splotches of mud on your shoes and having to drag more than enough muck to fill a pig’s sty.

Understanding how a bike’s gears work

A bike moves when a front cog wheel (professionally referred to as a chain ring) spins, causing the chain attached to it to turn the cog wheels (cassette) to spin, thus resulting in the forward movement of said bike. Gone are the days when you had to climb off your bike when going uphill, or alternatively having to use way too much power to make the ascend.

Most bikes these days come fitted with a gear to help cyclists triumph over traditionally challenging obstacles.

Let’s now try to understand this process a little bit more by going by its individual components.

1. Chain ring and cassette

The cassette is attached to the rear wheel and can spin independently anticlockwise but causes the wheel to spin when rotated counterclockwise. For the gears to shift, the cassette must spin in pedaling motion.

The cogs on the cassette vary and may count from just one to as many as eleven and they are arranged in descending order, meaning the bigger the cog the lower the gear. The chain ring on the other hand is the complete opposite; the bigger the cog, the higher the gear, and most bikes have them from one chain ring to three.

The chain ring usually sets the amount of power output you want to use, while the cassette makes small adjustments to smoothen your ride (with regards to speed).

We already covered the topic of bike chains, so you should read the article to better understand how gears work.

2. Derailleurs

The shifter cable is connected to the shifter on the handle bar via the derailleur (VIEW PRICES HERE). The front (chain ring) shifter is commonly on the left side of the handle bar while the cassette shifter is on the right.

The front derailleur is attached (clamped) to the bike frame, right above the chain ring, while the rear derailleur is screwed on to the outer frame of the bike, right next to the cassette. The derailleur usually puts constant tension on chain and helps guide the chain to the next cog when the gears are changed. When a rider shifts a gear, the derailleur moves right or left; making the chain to go either up or down the cassette and chain ring.

3. RPM (Revolutions per minute)

One thing you will always want to keep in mind when switching gears on a bike is that maintaining your cadence is key. This is achieved by planning out your next step on your route/trail. Most people cycle at a speed of between 70-100 revolutions per minute (RPM). RPM is the amount of times a rider rotates their legs on the pedal.

This simply means that higher gears require less RPM when compared to lower gears, which is why riders use lower gears when going uphill since the amount of effort required to move the pedal is very low.

So, knowing what terrain you are approaching is very crucial, since changing gears when already engaged on a steep climb puts strain on the shifter cables, which in turn starts to wear out and will make shifting gears extremely strenuous, almost impossible, and an overall bad biking experience, since your body is also affected.

There’s an online program for calculating your bike’s speed relative to its rate of revolutions per minute which you can access by clicking here.

If you choose the wrong gear pairing, the strain is not just on the bike, but also on your muscles and joints and not to mention a complete waste of energy. Shift gears early to avoid this.

What to Avoid When Shifting

One of the things to try as much to avoid when shifting gears is something called cross chaining. Cross chaining is when the chain is not kept straight when being shifted and occur when the chain is on the big cog on the chain ring and the big cog on the cassette. Though the bike will still be moving, this kind of shifting wears out the teeth on the cogs and may even cause the chain to split. It also leaves you with minimal shifting combinations when you really need them most.

Ride On!

Knowing how and most importantly when to shift gears on either a mountain bike, a road bike or even a beach cruiser, is not as complicated as you may have initially thought. Just as long as you can remember that high gears (i.e. big chain ring and small cassette) are good for speed and require a lot of energy to use and lower gears (i.e. small chain ring and big cassette) are good for more challenging obstacles and require less energy, enjoy the open road as much as you can.

Read our other article on gears by clicking here.

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