Looking to find a chainstay (universal) mounted chain tensioner or retention device. I saw one in singletrack I think, don't have the mag with me now so can't look, the september one, on a new bike which is part of the frame. Essentially it looked like an O ring hanging down to guide the chain through, pulling the chain up close to the chainstay.
I found a Brand-X one on CRC, but can't seem to find many more. Are they common? Do they work? Really I think they look pretty cool but I am running 1x9 and still get the chain coming off when doing large drop offs etc. and wonder if this will resolve those issues.
I tried making a couple of DIY ones which I am usually OK at, using couple of bits like a headset spacer and 2 cable ties crossed over, as well as the neck of a sprite bottle with 2 cable ties, but both were too flimsy and they weren't actually long enough such that it didn't drop into the gap between links, making it snag quite a bit.
I am thinking about something like an enclosed jockey wheel, somehow hanging off the frame near to where the rear wheel passes by. This allows the gears to work efficiently, but retains the chain at the important point. I think this could be quite a fun project, but would like to see what else is out there for inspiration and, quite frankly if it's been done well, I'll try one of them !
edit: just found http://www.youtube.com/watch?v=rxUXmQsjiiU
looks perfect... bar the fact I don't have a bionicon, and therefore that mounting method would not work. But I like the tube.
edit edit: looks good http://www.bionicon.com/ac/c-guide-v02 - where can I get one!?