Which Cog is Gear 1 on a Bike? (Understanding Your Bicycle)

Back in the day, I had a bike with 3 gears. On the twist grip gear shifter, these were helpfully labelled 1, 2 and 3. This made things easy. I knew when I was in gear 1…2…or 3, because the gear shifter told me.

Nowadays, bikes come with a lot more gears than my old bike and they don’t tend to be so helpfully labelled.

So, how do you tell which gear you’re in? Most importantly, how do you know which cog is gear 1 on a bike?

Quick explanation

It’s actually quite easy to tell which is gear 1 and I’ll show you how with a few simple diagrams to illustrate.

First though, I want you to hop on your bike and look down on the right-hand side so you can see the right pedal and the bike chain. These components, which includes your pedals, chain, front cogs (known as chain rings) and rear cogs (known as the ‘cassette’) are called the “drivetrain”. This is the power mechanism that drives your bike forwards as you pedal.

You’ll be in gear 1 when the chain is on:

  • The smallest chain ring at the front (this will be the cog closest to the bike frame), and
  • The biggest cog in the rear cassette (this will be the one closest to the rear wheel)

To get into gear 1 whilst you’re pedaling:

  • Use the left shifter to move the chain to the smallest chain ring, and
  • The right shifter to move the chain to the largest cog in the rear cassette

Specific examples showing Gear 1 with diagrams

Let’s illustrate that with some diagrams to show exactly how this should look on your bike. No matter how many gears you have.

We’ll look at three different examples: a triple chain ring bike (these often have 21, 24 or 27 gears), a double chain ring bike (16, 18 or 20 gears normally), and a single chain ring bike (up to 11 gears).

In each of these, you’ll see that the chain is on the front and rear cogs which are closest to the bike. This is worth bearing in mind as a general rule of thumb – to make pedaling easier, move the chain onto cogs closer to the bike.

Triple chain ring bike

gear 1 on a triple chain ring bike

On bikes with 21, 25 or 27 gears you should see 3 chain rings at the front where the right pedal attaches to the bike.

When you want to get into gear 1, you should shift the chain so that is on:

  • The smallest cog at the front, and
  • The biggest cog at the back

Double chain ring bike

gear 1 on a double chain ring bike

On bikes with 16, 18 or 20 gears, you should see 2 chain rings at the front.

To get into gear 1 in this situation, shift the chain to:

  • The smallest cog at the front, and
  • The biggest cog at the back

Single chain ring bike

gear 1 on a single chain ring bike

Bikes that have a single chain ring at the front, will normally have up to 11 gears.

On bikes like this there will be a single gear shifter and this operates the derailleur at the rear wheel.

Use the shifter to move the chain to the biggest cog on the rear cassette at the back wheel and you’ll be in gear 1.

Conclusion

So, there you have it. Gear 1 is an incredibly useful gear when you need to climb steep hills with ease.

Finding gear 1 is easy too – just use the gear shifters to move the chain so that it is on the front chain ring closest to the bike and the rear cog which is closest to the back wheel.

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