I was given a used specialized rock hopper last year but the seat angle is too high in the front. I've loosened the hex sockets beneath the saddle to adjust the angle but it always screws back in the same. Any help?
You have to loosen the correct bolts.. Its not the seat tube one (attached to the frame.) On most saddles these days there is just one or two bolts that allows for rail and angle position. If you have a forward and rear bolt fitting.. You need to loosen BOTH bolts.. otherwise the seat angle will likely stay the same. To lower the front of the saddle start to tighten the forward saddle bolt first and then the rear.. These bolts are effectively a cradle system so adjusting one has an effect on the other, you just set the appropriate seat angle and ballance the bolt torque evenly..
If the rocker has stuck... Loosen the adjustment bolt/bolts quite a bit, then use either a plastic mallet or small hammer and piece of wood to tap on the adjustment rocker, this should loosen it up and allow you to adjust the saddle angle.