| thicker oil slows the compression damping down so it takes longer to get to bottom out but it still will bottom if the bump force is big/fast enough. a combination of thicker and more volume might help but it all depends how far out the springs are or whether its actually to much rebound packing the fork down ( the fork can't recover from one bump before it hits another so eventually it runs out of travel)
Preloading a spring with more washers won't make it harder, it'll increase the ride height but thats all. a spring moves a set amount for a set load, so its rated as say 10kg/mm it'll take 10kg to move it 1 mm and no matter how much you push it it down it'll always take the same 10kg to move that 1mm until the coils on the spring bind together. if you start with a higher ride height there is less chance you'll bottom it as the fork needs to move further. try and set sag up correctly and if possible swap the spring to a one which is correct. |