Why the 'right' bike fit is a range, not a number

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

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 individual. Your correct position depends on your body and your goals, so a friend's correct position is not yours.
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.

Here is an example of how the saddle height fit window looks like inside BFF EZ. The green band is the range where your fit is most likely to be comfortable and effective. The yellow and red areas above and below it are outside the window. Tap the markers for the details.

One distinction worth keeping straight: BFF EZ doesn't build a customized window around a profile of you. It checks you against a target range for your bike type, established fitting standards, and patterns of completed fits from professional bike fitters, adapting the knee angle target to how you actually pedal (read from your video). The window is individual because riders differ, so your body stays the final judge of the right spot inside it.