Weavile's Speed tier is unique to Weavile, Swellow, and some other uncommon threats, so max Speed is rather unnecessary. Stick with 216 Spe EVs to outrun Dugtrio / Alakazam.
You can AC mention max Spe EVs; most DD Nite are max Atk / max Spe, so I wont bother with the extra Spe EVs, alexwolf. It's still gameover if DD Nite carries ExtremeSpeed, and Weavile can always Ice Shard for the revenge-kill anyway.
OO mention Swords Dance ;o