remember they are frame sliders not plastic sliders.. ment to portect your frame. they work well in most cases....stay away from metal ones, they dig in to the pavement then send you bike tumbling which like 90% of the time ends up going end over end fucking all your shit up. the plastic ones slowly get filed down by the pavement keeping the bike from going into a nasty tumble.

the one that "recoils" i think the material in called derlin, they dont break on sudden impacts like some plastic ones. they kind look like a mushroom.

you need sliders and swing arm spools to keep the damage to a minimal if you have a misshap.