Chain tensioner for surly crosscheck?
 

I initially thought tensioners were only for frames with track ends until I saw a tuggnut used on a crosscheck. I'd like a recommendation for a good chain tensioner, non tuggnut (something less flashy). Any recommendations?

MKS chain tensioner

http://farm1.static.flickr.com/206/4...b0ef1e.jpg?v=0

Why do you feel you need one though? The Crosscheck has horizontal dropouts, so the axle is held in place and the chain is tensioned by the weight of the frame. A chain tensioner will actually pull the chain out of tension on horizontal dropouts, right?

Lately the wheel has been sliding forward, leaving the chain slack and jumping off the chainring.

Have you tried tightening the axle nuts or quick-release skewer more than usual?

I have, and it sort of fixed the issue.I'd just like a tensioner for backup.