servo shopping done:
i have these in several of my 1/10's, redcats/traxxas ect.
they are cheap, metal geared and higher torque that most servos you get in RTR vehicles. you cant beat the price. go ahead and order 2 or 3. you wont regret it.
on the volcano, is it brushless or brushed?
if brushed, get a traxxas xl-5 ESC
if brushless, get an ezrun 35amp. or, if you can pony up a few more bucks get the 60amp.
the ezrun esc's are also on the site with the servos.
an yeh, concrete is murder on RC's! i used to jump my traxxas rustler vxl at the skate park. 4 sets of shocks, front bumper, reciever, rear hub, camber link later i decided to stick to dirt/grass.