If your treadmill is making a knocking noise when on a slight incline it could be that the frame is touching the bump stops. It might be worth trying the treadmill without the bump stops installed or increasing the treadmill incline slightly.
What are bump stops?
The bump stops are designed for the frame to rest on when at 0% incline. This provides a much firmer running surface as the incline mechanism does not provide a cushioning effect. The removal of the bump stops allows the incline mechanism to absorb more movement between 0-2% incline.
What will I need?
To undertake this you will need:
1. Star screwdriver.
1. Locate the bump stops mounted on the bottom left and right side of the frame base.
2. Remove the bump stops using a star screwdriver. Keep the bump stops and screws safe in case you want to install them at some later stage.
3. Ensure the treadmill base and running frame wheels are level.
4. Job done.