Free Bike Fitting Tools
VeloArena — Data Duel Arena ⚔️ BETA
Climb legendary cols with your real FTP & weight: 30-second sim verdicts, or ride it live in 3D — drafting, sprints, W′ management. Nine courses, four procedurally-generated seasons. Send async challenge links or race friends head-to-head in live P2P rooms. Full English UI.
VeloTunnel — Online Wind Tunnel 🌬️
A 2D fluid simulation in your browser: switch positions and wind speeds, watch drag change in real time, upload a riding photo to put your own position in the wind, and test drafting. (UI in Chinese — fully visual.)
Rider Power Card 🚴
Enter your best power numbers or pull them from intervals.icu in one click — get a five-axis radar card on the Coggan power profile: overall score, category, rider type (climber / sprinter / diesel…), saved as a shareable image. (Chinese UI for now)
Bike Size Calculator 📐
Confirm your frame size in 30 seconds before you buy: height + inseam to road/MTB/hybrid sizes in cm, inches and letters, with charts and between-sizes advice.
Saddle Height Calculator
Enter your inseam and instantly get LeMond (0.883) and Hamley 109% saddle-height references, in cm or inches.
FTP Calculator
Enter any 5–40 minute all-out test power and your weight to estimate FTP and W/kg, with per-duration factors and a power-duration curve.
Cycling Guides (Knowledge Base)
Knee pain, low back pain, saddle height, crank length, TT position — research-backed fitting content with a citation library.