When you are worried about any noise, ask your supporter to ride Cycling Chair instead of you.
Ask them to carefully pedal.
Do you see the same symptom?
Most of the time, you won’t.
The tips for smooth pedalling are,
to use your pelvis and upper body, rather than legs.
People tend to focus on pushing on pedals.
But did you know, you have to be pulling the other foot at the same time?
This can be more easily achieved if you
twist your pelvis,
making the difference in physical distances of right hip and left hip, from the pedal.
This article applies to any body size.
It explains the practical every day practice for smooth pedalling.