Any one can shoot me some pointers on what to do to change the oil and what oil to use. i have looked online for a Manual but nothing found. For some reason they are waaaayyyyy to "Squishy" to even ride comfortably. I am hoping that changing the oil in them will stiffen them up quite a bit. They are to the point where they will almost bottom out from just bouncing on the bike. Any help would be great. Thank you