Gearbag by Gatesnap Labs

Gearbag calculates your gear-inches and rollout based on your rim, tire, sprocket, and cog; then shows your gearing, along with other possible sprocket and cog combinations that are incrementally smaller or larger. Now, you can dial your bike in for race day without the guesswork.
Considering picking up a cruiser? Has your child outgrown Expert-sized rims? New tire sponsor? We've got you covered. Gearbag has a "Compare Bikes" mode - enter your current bike, then choose a second rim and tire to calculate equivalent gearing. Spend less time doing algebra, and more time in the winner's circle.
Features:
- 32-51T sprocket options with support for decimal gearing
- 12-19T cog options
- Tire options for most major makes and models in 18, 20, OS20, 24, and 26-inch sizes
- Show results in Imperial (English / American / Standard) or Metric
- Supported languages: English, Spanish, French, German