Board Thread:The Flash discussions/@comment-28354683-20160501172546/@comment-24152851-20170609032730

Hold up. Barry did not beat Zoom using tachyons, he just narrowed the speed gap between them. Barry only beat Zoom after he got the huge speed boost from being inside the Speed Force, which neither Zoom nor Eobard would get since they're evil. Eobard merely used the tachyons to push past Barry's speed, as before he was running on fumes due to the Speed Force stripping him of his speed. The Zoom that stole Barry's speed should be way faster than even tachyon Eobard.

One more thing. The tachyon prototype is a machine attached to a speedster, while with Zoom it's a part of his physiology. So if Zoom figured out how they were getting faster, he could easily swipe the tachyons and slow them back down.