Derailleur Logo


One gearing
to rule them all.

Questions? Answers.

Derailleur helps cyclists analyze and optimize gearing configurations on their bicycles. Designed to be the best and easiest-to-use app for calculating gear ratios, Derailleur combines precise calculations with an intuitive design, so that changing a bicycle configuration is straightforward.

What is Derailleur?

Derailleur+ combines everything you love about Derailleur, along with even more great features. When you upgrade to Derailleur+ not only will you be able to create an unlimited amount of configurations, but you’ll also get an even greater experience.

What is Derailleur+?

Derailleur packs powerful features for free like working offline, saving configurations, importing and exporting DRL files, and much more. Intended to cater for all cyclists and modern bicycles, Derailleur offers a wide range of configurations for BMX, MTB, road bikes, fixed gears and track bikes.

How is Derailleur different from other calculators?

DRL is a file format developed by Derailleur in 2023 to facilitate sharing configurations between users of the app. It has a file name extension '.drl', and it can be shared by email and with most messaging apps.

What is a DRL file?

Yes. Everyone on the free plan get to create one configuration for free. You can upgrade to Derailleur+ at any time for more configurations.

Is there a free version of Derailleur?

Derailleur is available to download for iPhone on the App Store. To get the newest features, make sure your device is running the latest version.

Where can I download it?

App Icon


No iPhone?
Not a problem.