Bought this bike at Decathlon Philippines (Festival Mall). Im enjoying this very much but I do have some questions. I "sometimes" feel a very slight jerk when I pedal. Not very consistent and it seems to happen only when my pedal force is not the same between my right and left legs. Not really a concerning issue but curious if it is normal. Also, the heart rate belt does not seem to work, though I haven't t tried replacing the battery.