These are the infamous bungies. They are giant elastic rubber bands that cushion the transfer of weight to the wheels and frame on landing. They are infamously hard to replace. Fortunately, mine are still OK. You can see the brake fluid hoses in the top of the picture running from the rudder pedals out the bottom of the plane to the brakes. The yellow stuff in the upper part of the photo to the left is brake fluid leaking from a brake cylinder. We fixed that.