A well designed bike doesn't. I'd put my commuter, an old Raleigh MTB with steel forks and 26 x 1.5 tyres, against the current rash of bikes with cheap suspension forks. Raleigh know how to build a decent bike by now, and steel forks and reasonably chunky tyres soak up everything that passes for a road around here. On towpaths etc it's all you need.
foxwelljsly
Me too, I ate one sour too.
For front suspension, smooth travel and damped rebound, serviceable and doesnt suffer sticky stanchions after 6 months.
I wouldn't buy a new bike with suspension for less than £1k, unless I planned to stick some S/H serviced old Fox RL's or similar on it.