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.
Many equipments made for people with disability are designed specifically only to those populations. They won’t show any difference whether or not the rider’s body is controlled appropriately or not.
What happens if the rider keeps on the inefficient body use? It will lead to injury as well as damages on the equipment.
When we use Cycling Chairs, especially COGY, we need a mindset of cyclists rather than a person with special needs. If the unbalanced weight bearing leads to the noise, are you happy to make effort to try achieving better balance?