Hey I've been reading the forums for a while now as there aren't too many quality trials forums based here in southern Ontario (Canada :-). Basically I came across a discussion in the members' area about tensioners, found here: http://www.trials-forum.co.uk/forum/index....showtopic=61626 . After the majority of the posters came to the conclusion that running a tensioner was a better idea than not running one, and then started throwing out names of tensioners, I couldn't help but notice that the Rennen Rollenlager was not brought up. Not sure if they are just not shipped to the UK or what the reason was, but I figured I'd throw this into the conversation as a huge recommendation. You can check out the rollenlager here http://www.rennendesigngroup.com . Slightly expensive but for the money you're getting a nearly bombproof (will literally handle more abuse than you can throw at it), light, and effective tensioner.
If there is indeed a reason that the rollenlager is well-known but not popular in the trials community, please let me know!