How Qoolbike dynos-x1 Power Meter Work?



This article was written to answer a few questions on us about the technology base of Qoolbike dynos-X1 power meters such as; Is it possible for Dynos-X1 can measure the cycling power without using a strain-gauge sensor like other power meters? or Why does dynos-X1 looks just like an ordinary cadence sensor? or Does dynos-X1 uses a guesstimate method such as strava applications?

The answer is; dynos-X1 can measure the cycling power even though it doesn’t use a strain-gauge sensor. Our explanation will consist of two parts; The first part describes the principles of bicycle motion based on physics theory and the second part is how we get parameter data that required by mathematical equations to calculate the cycling power of the theory of physics above.

Our goal of designing anti-mainstream power meters are;

(1) Affordable prices; The use of the strain-gauge sensor causes high production costs, the dynos-X1 is easily assembled because it uses a full electronics components design (2) Can be used on all types of bicycles; because it is not in the form of certain bicycle components such as pedals, crank, spider etc. (3) Easy to install without using special tools; even easily moved from your one bike to another bikes and finally (4) Increase the results of your cycling training with special mobile apps support designed for Qoolbike dynos-X1 Power Meter.

Part 1 : Physics of Bicycle

Part 1 : Physics of Bicycle

crank, chain ring, chain, sprocket gear

Shown are crank, chain ring, chain, sprocket gear and rear wheel (drive wheel) on the flat surface

rear wheel (drive wheel) on the flat surface
Physics of Bicycle Table
Torque equations
Cycling power is torque on pedal multiply by average crank rotation
bicycle motion on surface up
bicycle motion on surface formula
bicycle motion on surface down
bicycle motion on surface formula

Shown bicycle motion on surface with slope angle ϴ

torque on bicyle pedal
cycling power formula

The above equation shows how to calculate the cycling power based on the principle of physics from a bicycle motion Of course there are still some more parameters that need to be added to the details of the calculation such as the Rolling and Drag Resistance Factor.


In the next section it will be shown how Qoolbike Dynos-X1 can solve the equation above to get Cycling Power for you.

Part 2: QoolBike dynos-X1 power meter design and implementation

Part 2 : Qoolbike Dynos-X1 Power Meter Design and Implementation

Power Meter Design and Implementation

Power meter module (primary): installed on left crank of bicycle.
This module always connected with speed sensor module to calculate real time cycling power.  The data generated by this module are cycling power, Left/Right power balance (one of cycling dynamic), cadence and speed.  Power meter module has 2 bluetooth/BLE and 1 ANT+ wireless connection, IMU (Inertial Measurement Unit) sensors, digital motion sensors, hall sensor and slope sensors.

Speed sensor module (primary): installed on rear hub of bicycle.
This module act as client module to power meter module. Speed sensor module has 1 bluetooth/BLE and 1 ANT+ wireless connection and IMU sensors.

Zero marker module (primary): installed on seat tube of bicycle frame.
This module as a marker to power meter module to initiate all calculation for one crank rotation.

Bike Computer display module: installed on handlebar or stem.
If standalone, this module is lookalike simple bike computer for displaying very basic parameter, but if its work together as dynos-X1 and QoolBike mobile apps companion it will be very powerful bike computer.

QoolBike Smart mobile apps: available in Android and IoS smartphone device.
This application needed to set-up some primary parameter for power meter module such as type of bike, wheel diameter, rider weight etc. QoolBike mobile apps also provide data analysis that you can use to manage your cycle training program. With this application you can analyse your training progress with comparing individual parameter.

The modules marked primary must be installed and work together to be able to measure the cycling power. Bike Computer Display Module can be replaced with other computer bike (some features such as gear ratios will not appear in ordinary computer bike). Qoolbike Mobile Apps can also be used as a computer bike or just used when set-up Dynos-X1.

Take all the parameters of all sensors and put them in the cycling power equation :
cycling power equation



Why can we find this way to get cycling power?
Because we integrate all sensors reading in one system as part of our future QoolBike SmartBike concept.

Until this time you always buy electronic parts for bikes such as Speed/Cadence Sensors, Power Meter, Heart rate Sensors, Bike Computer even Mobile Apps separately and from different vendors. Data from all sensors will be read separately so that why it does not produce a comprehensive conclusion for you.

QoolBike SmartBike concept includes the concept of SmartRider too, in addition to reading the sensor of bicycle motions (Speed / Cadence, Power, Cycling Dynamic, Gear Ratio / Gear Shifter etc) we will also read rider’s vital Sign like; Heart rate, Body Temp, Fatigue & Stress Level, Hydration Level etc. With this concept, we expected you not only getting healthier but also felt safe and fun in cycling.

QoolBike Power Meter Concept