They come with 3 springs. The one installed is the middle, so there is one above and below in weight rating. I don't have my book handy to tell the exact weight rating. On the bottomout control, if you get the RC2 you get a low speed and high speed comression control. The high speed control would help in bottomout, but you'd have to be careful not to rely on it too much as you could get spiking if you dial in too much. I don't find any bottomout issues with mine with both compression controls set at the recommended wide open, minimum setting. There's quite a bit of compression tuning in this fork, and I'm sure you can dial in a fair amount without getting too harsh. You can't do an oil level adjustment in this fork like you can with most Marz forks.