KRENGO
NO

A tiny logger under the saddle

KRENGO

measures what you feel in the corner

Scroll

Every cyclist knows the feeling.

The bike leans into the corner, and for a second everything goes quiet.

Almost nobody gets to see it.

This is the story of one corner, ridden twice.

Act I

Without Krengo

Three corners. The rider only knows it feels fast.

He holds back. He brakes in. Little lean, low speed.

And pedalling? It starts late, because nobody knows when it is safe.

Illustration

Same corner. Now with the numbers in front of you.

Act II

With Krengo

Same three corners. Now the rider sees the lean as it happens.

He leans a little further, because the number says there is grip to spare. The speed stays.

And the moment it is safe, the signal comes: PEDAL NOW.

First to the line. Last lap’s ghost is still rolling.

Illustration

The difference, same corner

Without 0° 0 km/h · pedals out late
With 0° 0 km/h · pedals out on time

Illustration of a corner

Try it yourself

Tilt your phone.

This is what Krengo measures, 20 times a second. Lean your phone like a bike and watch the angle. On a computer: drag, or use ← →.

Lean 0° Deepest –°
20 times a second
Tilt your phoneDrag or use ← →

Your phone’s sensor stands in for Krengo

Where we’re headed

Here is how it could be.

Lean angle stops being a table of numbers after the ride. It sits on your bike computer while you ride.

Bike computer showing a live lean bar in a data field. Drawing of the vision.
01 A live lean bar as a data field on your bike computer, for example a Garmin Edge.
Slim aero box mounted on the saddle rails under the saddle, side view. Drawing of the vision.
02 A small, light circuit board in a slim aero box on the saddle rails.
Small circuit board from above with ESP32 module, sensor and battery connector. Drawing of the vision.
03 The board: ESP32, sensor and battery on one small surface.

The road so far

Built in small, safe steps. Here is what is in place, and what is coming.

  1. A readout that checks itself

    One copy of a log was missing its first minute and nobody noticed. Now every file travels with its length and a checksum, and is rejected if they don’t match.

  2. The box is drawn in code

    The enclosure is modelled in OpenSCAD, and a separate checker derives its own dimensions from the datasheets.

  3. Fourteen hours on one battery

    The logger ran 14 h 48 min at 20 Hz, 1,066,089 rows, and only stopped when the battery ran out.

  4. GPS cross-check and an honest README

    Comparing against a real GPS ride showed a different filter, not a sensor fault.

  5. No more drilling

    One printed box on the bottle-cage bolts, no soldering. 4 h 19 min and 190 g of PETG.

  6. Dress rehearsal on a synthetic ride

    Peaks of +35°, −35° and +35° read back as 35.00°. A bug in the angle formula for a tilted sensor was found and fixed before any ride.

  7. The box moves to the seat tube

    The down tube sits too close to the chainring, so the box gets its spot on the seat tube. Next up: a clearance check on the bike.

  8. Out on the road: first ride, first real curve

    Mount, charge, ride, read out, and lay the curve next to the GPS track.

  9. A lighter board and an aero box

    Once the logger has proven itself on the road, it gets small and sleek.

  10. The lean bar on your bike computer

    Live view while you ride. Where we’re headed.

See the corner. Take it faster.

THE END

Krengo · hobby project · no tracking, works offline