This might not please the Terratrike people but... I bought a Rover Tandem some over a year ago. About a month. And a half ago while riding I/we noticed it was riding hard! We also noticed that the wheels were leaning in on top, and quite a bit too! We got home and parked the tandem and the next day I went out to diagnose the problem. After turning the tandem on it's side the problem was very obvious! There is a design flaw on the front cruciform. Those of you who have Blue Rovers would do well to turn them on their side and look the frame over. The "gusset" welded to the round tubes across the square tube is the point of failure, The welding procedure on this gusset is the problem, because this gusset was welded to the weakest point of the round tubes. On my tandem the one end of the gusset was cracked, and the other was not only cracked, but it broke the round tube half way around. This caused the frame to sag a half inch in the center, which caused the wheels to lean in at the top.
When you check your frame, look for rust on the ends of the gusset. This will likely indicate cracking. We are fortunate that ours didn't break completely, which would have damaged more of the trike.
Terratrike replaced the part under warranty, and out LBS didn't charge for replacing the part! This is wonderful! But, we live in Dodge City and there is no Terratrike dealer here. We took the trike to Harley's in Hutchinson, which is where we bought the tandem. They are our closest dealer, about 2 and a half hours away.
Talking to the manufacturer of Rans bikes (they are 30 minutes from us)... Jerrill confirmed my thought (that this is a design flaw). I have been a welder/ metal fabricator for 27 years and by experience know that this design will cause trouble.
Check your trike for this problem! This is the only issue we have had with the tandem beyond normal maintenance issues. We all know maintenance is required so these are really not issues!
Take care! Happy riding! keep on triking!