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Cycling App of the Week: Bike Gear Calculator

A quick and easy way to compare different gear options

 What is it?    

Bike Gear Calculator is a quick way to compare different gears on your bike and on setups you’re considering, and for seeing how fast you’ll be travelling in a given gear at a particular cadence (pedal revolutions per minute).

You just add details about your bike and all the maths is done for you. Of course, you could do the calculations yourself, or use something like Sheldon Brown’s Gear Calculator, but this app makes things fast and simple.

A free version of the Bike Gear Calculator is available, with £1.99 getting you a more advanced edition.

What makes it unique?      

There are quite a lot of gear calculator apps out there but what makes this one especially useful is that you can just spin the chainring and sprocket graphics to the relevant positions, and adjust the speed and cadence settings via little sliders on the side of the screen. The ability to compare two different gears alongside one another is handy too. 

Bike Gear Calculator

Say you’re trying to decide between a road bike with a 53/39-tooth standard chainset and a 12-28-tooth cassette, for example, and 52/36-tooth semi-compact chainset with a 11-28-tooth cassette. The Bike Gear Calculator app will comparing the top gear (or any other gear) in each, expressed in various different ways including gear inches, gain ratios, development metres and your speed at a given cadence. 

You can also create complete gear charts for your bike that you can store or share by email.

How can it help me?    

This app can help you work out the best setup for your bike. If you’re struggling to get up hills with your current components or you find your cyclocross bike overgeared, how much difference will changing the cassette make compared to swapping the chainrings? You can check out the results of the various options open to you in seconds.

The app tells you how fast you’ll be going in a chosen gear at any cadence you choose, and you might use this information to inform your riding technique. It can tell you, for example, that if you’re in the 53-tooth outer chainring and the 23-tooth sprocket, using 700 x 25 tyres and pedalling at 90rpm, you’ll travel at 16.2mph (you can switch to km/h if you prefer).

If you want to maintain that speed when you drop to the 39-tooth inner chainring, you can select the 17-tooth sprocket and pedal at the same cadence, or go to the 19-tooth sprocket and pedal at 100rpm, or go to the 21-tooth sprocket and pedal at 111rpm. 

If you’re a time trialist or you take your Strava KOMs very seriously you could even use the app to help plan your next assault. Want to average 22.1mph and your preferred cadence is 90rpm (same wheels as above)? Your best gear, assuming consistent terrain, would be 53 x 17 or 50 x 16.

Where can I get it?

The Bike Gear Calculator is available in both the Play and iOS app stores.

Arriving at in 2017 via 220 Triathlon Magazine, Jack dipped his toe in most jobs on the site and over at eBikeTips before being named the new editor of in 2020, much to his surprise. His cycling life began during his students days, when he cobbled together a few hundred quid off the back of a hard winter selling hats (long story) and bought his first road bike - a Trek 1.1 that was quickly relegated to winter steed, before it was sadly pinched a few years later. Creatively replacing it with a Trek 1.2, Jack mostly rides this bike around local cycle paths nowadays, but when he wants to get the racer out and be competitive his preferred events are time trials, sportives, triathlons and pogo sticking - the latter being another long story.  

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