Why bike fit matters, and what "right" actually means

The phrase we'll use throughout this course is the fit window: a range of bike adjustments inside which you'll be comfortable and ride well. The BFF EZ app uses the same idea. Every recommendation it gives you is framed as whether you're inside your window or outside it.

Drag the saddle and find the window for yourself:

Three things are true of the window:

1. It's a range, not a point. Two riders with similar bodies might settle on slightly different saddle heights inside the same window and both be correctly fit. There isn't one number to chase.
2. It's specific to you. The window is set by your body, your bike, and your riding. A friend's correct position is not your correct position.
3. It moves. The window shifts as your flexibility changes between seasons, as you recover from injuries, and as your goals change. Periodic re-checks are part of staying fit, not a sign you got something wrong.