Bike Gear Calc & Maintenance

Put in your chainrings, cassette, tyre and crank length, and the whole gear table appears: gear ratio, gear inches, metres per crank turn, gain ratio and speed at your cadence, for every combination. Cross-chained combinations are greyed so you can see which gears you actually use.

A bike gear calculator for road, gravel, mountain and commuter bikes. Pick a common crankset and cassette from the presets or type the teeth yourself. Wheels come from the ETRTO size on the tyre sidewall, or from a roll-out you measured. Save a setup per bike and switch between them from the top of the screen.

Planning a change? Compare two setups side by side: how much lower the bottom gear goes, how much top end you give up, which gears overlap and where the jumps get big, charted gear by gear. Pro also opens the speed table from 60 to 120 rpm, tyre pressure and chain length helpers, unlimited bikes, chain-wear logs, reminders, PDFs and backup restore. Choose yearly Pro with a 7-day trial or lifetime Pro. The app always shows the price Google Play returns for your country.

Bike maintenance follows the parts that wear: chain, cassette, chainrings, tyres, brake pads, cables, bearings and suspension service. This bicycle component tracker gives each part its own interval in distance, months or ride hours, whichever comes first. Add distance by logging a ride or typing the odometer; nothing is tracked by GPS. Export all my data is always free, and Delete all data removes bikes, parts, setups, records, settings, reminders and local files.

No ads, ever. No account, no location, no Bluetooth, no sensors, no uploads: everything stays on your phone except Google Play Billing diagnostics. Tyre pressure is a starting point only; never exceed the maximum on your tyre or rim. Build sheets and service histories are personal records only. For personal record-keeping. Not an official document.