Originally Posted by
PeteHski
Modern MTBs achieve a long wheelbase and stability from slacker head angles rather than super-long chainstays. The latter are not popular because they make it harder to pop the front wheel up.
Not necessarily for popping a wheel up but for general maneuverability and responsiveness. Understand that they're also running 2.5-3.0" tires and full suspension to keep the rubber side down, and the slack head angles are for downhill stability. Mountain bikes also use super steep seat tube angles to shift the rider's weight forward in order to keep the front wheel planted when climbing, and high bottom brackets to keep the pedals and chainrings from hitting rocks. There's very little MTB geometry design that translates to effective road riding.