Talk:Riven/@comment-5877442-20130724214917/@comment-4947142-20130725035750

Black Cleaver is your #1 CDR item, and the passive fits Riven's combo playstyle.

Other usable items that include CDR are: Ionian Boots (15%), Spirit Visage (20%), Spirit of Elder Lizard (10%), Spirit of Ancient Golem (10%), Frozen Heart (20%).

I'd personally go with Cleaver/Visage, since those are excellent items for Riven. However that gives 30%. You can fill the remaining 10% with the jungle items if you want, or the Ionian Boots. Either way gets you some wasted stats though.