What knee tracking is
Seen from the front, each knee should travel up and down in a fairly straight line over the pedal.
Some riders’ knees drift in toward the top tube, others flare out, on every stroke.
Why it costs you
A knee that wanders sideways sends some of each push in the wrong direction.
It is often a sign that something in the set-up, such as saddle height or cleat position, needs a look.
What to check
Check saddle height first, since a saddle that is too high or too low changes the knee path.
If the knee still wanders, look at cleat position and stance width with a fitter or a bike shop.
One check to try
- Pedal steadily for a minute, filmed from the front.
- Watch one knee at a time on the replay, top to bottom.
- Change one thing, ride another minute, and film again.
How to film it so Llyr can read it
Stand your phone in front of the bike at about knee height, centred on the bike, with your whole body in the frame.
The front view shows which way each knee travels. Pedal steadily for at least thirty seconds.
Already have a clip? You can import a video you filmed earlier instead. Read the full filming guide.
What you see in Llyr
When a knee drifts inward, stroke after stroke, Llyr names it Knee in. A knee that flares out is Knee out.
Either one is shown on a still from your own video.
The cue to take into your next ride is Knees in line with feet.
Llyr is a second set of eyes, not a professional bike fit. Check each correction on the replay, and if a fitter sees it differently, go with your fitter.