Bright.Cards

Master Your Bike's Performance with Professional Gear Ratio Analysis.
Transform your cycling experience with DrivetrainPro, the ultimate app for precise gear ratio calculations. Whether you're a weekend rider, competitive cyclist, or bike mechanic, unlock your bike's true potential with instant, professional-grade analysis.
Why Gear Calculator?
Stop guessing which gear to use! Calculate exact gear ratios, gear inches, and development distances for any bike configuration. Make informed decisions about upgrades, optimize your performance, and save money by avoiding incompatible purchases.
Key Features:
Complete Drivetrain Support
- 1x, 2x, and 3x chainring configurations
- Major cassette brands: Shimano, SRAM, Campagnolo
- Custom chainring and sprocket combinations
- All wheel sizes: 700C, 26", 27.5", 29", and more
- Precise tire size and crank length adjustments
Multiple Calculation Units
- Gain Ratios for mechanical advantage
- Gear Inches for traditional measurements
- Development for distance per pedal stroke
Instant Professional Results
- Real-time calculations as you adjust parameters
- Clean, intuitive interface
- Comprehensive gear ratio tables
- Perfect for on-the-go analysis
Perfect For:
Performance Cyclists: Optimize gear selection for training zones, race strategies, and different terrains. Find the perfect cadence match for maximum efficiency.
Everyday Riders: Understand your bike better! Discover which gears work best for commuting, recreational rides, and challenging climbs.
Bike Mechanics: Provide professional consultations with instant, accurate calculations. Compare different component combinations for customer recommendations.
Touring & Bikepacking: Calculate optimal gear ratios for loaded riding, long climbs, and varied terrain adventures.
Smart Benefits:
Save Money: Avoid buying incompatible components
Boost Performance: Find optimal gear combinations for your riding style
Professional Accuracy: Calculations used by bike shops and mechanics
Easy Comparison: Test different setups before purchasing
Comprehensive Database: Stock cassettes from major manufacturers
Custom Flexibility: Enter any chainring or sprocket combination
How It Works:
1. Setup: Select your wheel size, tire width, and crank length
2. Configure: Choose your chainring setup and cassette type
3. Calculate: Get instant, comprehensive gear ratio analysis
4. Optimize: Compare different combinations to find your perfect setup
Real-World Applications:
- Climbing: Find easier gear ratios for steep ascents
- Speed: Optimize higher ratios for flat terrain and racing
- Loaded Touring: Calculate ratios for heavy bikepacking loads
- Component Upgrades: Preview changes before purchasing
- Bike Builds: Design optimal drivetrains from scratch
Requires iOS 14.0 or later