Joined: Feb 2012
Posts: 19,381
Likes: 5,527
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
A recumbent trike with a coaster brake? I have been the recumbent guy at the shops I've worked ever since I had my Avatar 2000 and I've never seen this spec as stock. The chain path and the tubes and pulleys certainly would make a non der tensioned chain run interesting.
We need more info to be better able to help. Photos are a real aid to our understanding what hasn't been yet mentioned. Where does the chain derail? Front, rear of in between? Andy.