Klinklang@sitrus berry or leftovers or life orb
Ability: clear body
Evs: 252 attack, 252 sp. attack/ 252 speed, 4 def.
Recycle/ charge beam/ lock on
Zap canon/ thunder bolt
Shift gear is just awesome. Its boost klinklang's already decent attack while doubling its speed and with a base 90 speed, is almost impossible to out speed unless the other Pokemon has a boost. Gear grind hit for 150 damage when STAB is included. Recycle recycles thee sitrus berry, making sure klinklang has a semi-reliable way of recovering, although I don't recommended it much. Lock on allows zap canon to have perfect accuracy, while charge beam gives a boost to its sp. attack. Zap canon is raw damage and paralysis. Thunder bolt is for accuracy.
The evs maximize klnklang's damage output, while adamant gives a boost to its attack, which is good for gear grind. Sitrus berry is to recover health lost from setup, leftovers Is passive recovery, and life orb is a staple for attackers.
Hoped this helped:)