With 252 EVs, his Speed reaches 139. At +4 (2 Shift Gears), it reaches 556. Combine that with Bullet Punch, and Ferrothorn becomes a Speed demon. Well, not quite, but close.
And yeah, I typed the EVs wrong. Means to say 252 Atk / 4 SDef / 252 Spd. Don't know why I did a bulky spread, but...