TXZOO

Hey, this is my first time posting at this site. I just got my new ZOO (actually used but in very good condition) with horizontal dropouts. There are two tensioners made by Threshold, and they are not doing a very good job. Both are bowing and the wheel after doing some 5+ foot drops creeps forward. Are these tensioners intended for use on a 26" bike, or do I need to get a snail type tensioner? What are you guys using? thanks -thom