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Bicycle Crunch Rep Counter

Skip the mental math. Point your phone at yourself and every full-range bicycle crunch counts itself — sets, reps, and PRs logged while you train your core and obliques. Free in your browser today; coming to Google Play and the App Store.

Coming to Google Play & the App Store▶  Try The Rep Counter
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BICYCLE CRUNCHES7/ 10
Live screen in miniature — the app’s real bicycle crunch demo (side view), with the rep counter, form bar, and phase dot. On-device.
Straight From The App

HOW TO DO A PROPER BICYCLE CRUNCH

Setup  Lie on your back, side-on to the camera, hands by your head.

  1. Bring one elbow toward the opposite knee as you extend the other leg.
  2. Alternate sides in a pedaling motion.
  3. Keep it controlled — don't pull your neck.
Form cue: Elbow to opposite knee

Same sheet as the ⓘ panel in the app — animated demo included.

How The Counting Works

HANDS-FREE IN THREE STEPS

1

Prop your phone and get in frame

Phone at roughly torso height, set up side-on to the camera. A quick camera test checks lighting, distance, and angle before you start.

2

The camera locks a 17-point skeleton on you

GOODREPS measures your knee angle (hip → knee → ankle) on-device — no wearables, no clickers. A mat — no gear required.

3

Just work — the counter does the counting

A rep banks at the bottom (~80°) and re-arms near ~160°. Half reps don’t count; after 3 clean reps it calibrates to your range.

Under The Hood

WHAT MAKES A REP COUNT

Form Still Matters

COMMON BICYCLE CRUNCH MISTAKES

Pulling on your neck

Hands support the head lightly. Elbows wide; chin untucked from the chest.

Flopping side to side without extending

Long legs matter. Extend fully on each switch.

Racing until form dies

Smooth pedals beat frantic ones the camera cannot score.

Holding your breath

Exhale on the twist. Inhale as you switch.

Your Data

PRIVATE BY DESIGN

Rep counting runs entirely on your device — your camera feed is never uploaded.

Pose detection runs in your browser via TensorFlow.js. Camera frames are analyzed in real time and immediately discarded — nothing is recorded, nothing leaves your phone, and we never see them. Sign-in is optional; skip it and everything stays local.

FAQ

QUESTIONS, ANSWERED

Do I need any equipment to check my bicycle crunch form?

Just your phone for most variations. Add free weights when the pattern is clean — the app still scores the movement either way.

Does it work in a home gym or low light?

Run the built-in camera test first — it checks your lighting, distance, and angle with live green checks before you start. If a rep still slips through, manual counting is always one tap away.

Is my camera feed uploaded anywhere?

No. Pose detection runs entirely on your phone, in your browser. Frames are analyzed in real time and immediately discarded — nothing is recorded, nothing is uploaded.

Keep Going

RELATED GUIDES

Coming to Google Play & the App Store▶  Try GOODREPS Free

Free forever — camera counting for all 60 exercises, no account needed. Pro (voice coaching, programs, depth-camera form checks) is $7/mo, $49/yr, or $99 once. No ads, ever.