diff --git a/multi_tasking/bike_system.cpp b/multi_tasking/bike_system.cpp
index 53ed6c2..a50fa00 100644
--- a/multi_tasking/bike_system.cpp
+++ b/multi_tasking/bike_system.cpp
@@ -191,6 +191,7 @@ void BikeSystem::speedDistanceTask() {
 
     const auto pedalRotationTime = _pedalDevice.getCurrentRotationTime();
     _speedometer.setCurrentRotationTime(pedalRotationTime);
+
     _speedometer.setGearSize(getCurrentGearSize());
 
     _currentSpeed     = _speedometer.getCurrentSpeed();
diff --git a/multi_tasking/bike_system.hpp b/multi_tasking/bike_system.hpp
index c9149a0..19b449f 100644
--- a/multi_tasking/bike_system.hpp
+++ b/multi_tasking/bike_system.hpp
@@ -82,6 +82,9 @@ class BikeSystem {
     uint8_t getCurrentGearSize();
     void setCurrentGear(uint8_t gear);
 
+    void dispatch_isr_events();
+    void dispatch_events();
+
     // timer instance used for loggint task time and used by ResetDevice
     std::chrono::microseconds _resetTime      = std::chrono::microseconds::zero();
     std::chrono::microseconds _onGearUpTime   = std::chrono::microseconds::zero();
@@ -90,16 +93,23 @@ class BikeSystem {
     Timer _timer;
     // data member that represents the device for manipulating the gear
     GearDevice _gearDevice;
+
     //////////////////////////////////////////////////////////////
     // shared resources between the main thread and the isr thread
     uint8_t _currentGear     = bike_computer::kMinGear;
     uint8_t _currentGearSize = bike_computer::kMinGearSize;
     //////////////////////////////////////////////////////////////
+
     // data member that represents the device for manipulating the pedal rotation
     // speed/time
     PedalDevice _pedalDevice;
+
+    //////////////////////////////////////////////////////////////
+    // shared resources between the main thread and the isr thread
     float _currentSpeed     = 0.0f;
     float _traveledDistance = 0.0f;
+    //////////////////////////////////////////////////////////////
+
     // data member that represents the device used for resetting
     ResetDevice _resetDevice;
     // data member that represents the device display
@@ -126,9 +136,6 @@ class BikeSystem {
 
     // Tread for isr events
     Thread _isrEventThread;
-
-    void dispatch_isr_events();
-    void dispatch_events();
 };
 
 }  // namespace multi_tasking
diff --git a/multi_tasking/pedal_device.cpp b/multi_tasking/pedal_device.cpp
index c4c5214..06ecdb5 100644
--- a/multi_tasking/pedal_device.cpp
+++ b/multi_tasking/pedal_device.cpp
@@ -36,10 +36,9 @@
 
 namespace multi_tasking {
 
-PedalDevice::PedalDevice() {
-    disco::Joystick::getInstance().setLeftCallback(callback(this, &PedalDevice::onLeft));
-    disco::Joystick::getInstance().setRightCallback(
-        callback(this, &PedalDevice::onRight));
+PedalDevice::PedalDevice(Callback<void()> cbOnLeft, Callback<void()> cbOnRight) {
+    disco::Joystick::getInstance().setLeftCallback(callback(cbOnLeft));
+    disco::Joystick::getInstance().setRightCallback(callback(cbOnRight));
 }
 
 std::chrono::milliseconds PedalDevice::getCurrentRotationTime() {
diff --git a/multi_tasking/pedal_device.hpp b/multi_tasking/pedal_device.hpp
index 60ab832..8787548 100644
--- a/multi_tasking/pedal_device.hpp
+++ b/multi_tasking/pedal_device.hpp
@@ -33,7 +33,8 @@ namespace multi_tasking {
 
 class PedalDevice {
    public:
-    PedalDevice();  // NOLINT(runtime/references)
+    PedalDevice(Callback<void()> cbOnLeft,
+                Callback<void()> cbOnRight);  // NOLINT(runtime/references)
 
     // make the class non copyable
     PedalDevice(PedalDevice&)            = delete;
@@ -43,12 +44,6 @@ class PedalDevice {
     std::chrono::milliseconds getCurrentRotationTime();
 
    private:
-    // private methods
-    void onLeft();
-    void onRight();
-    void increaseRotationSpeed();
-    void decreaseRotationSpeed();
-
     // data members
     volatile uint32_t _currentStep = static_cast<uint32_t>(
         (bike_computer::kInitialPedalRotationTime - bike_computer::kMinPedalRotationTime)