I've got a Dahon Speed Uno that's about 4 years old that's used for a 3 mile ride to and from work daily, and it's been beaten on quite a bit over that time frame. The folding frame is wearing (most notably in the handlebar hinge), the cranks are starting to have issues, the pedals have needed to be replaced twice, now I need new wheels, etc.
So basically, I'm looking at buying a new bike instead of putting the money into repairing the old one. First of all, I love the simplicity of the Speed Uno that I have, and in general I take it around the city with no problems. The main areas where I use it are mostly flat. Even still, sometimes on large hills I miss having another gear to shift to. Because of this, the Tern Duo models that use the SRAM Automatix seem nearly perfect for me.
The problem is that I have seen zero reviews anywhere (on this forum or elsewhere) of either model. There must be people who have these, right? What do people think of them? Does the automatic shifting help, or is it more trouble than it's worth?
I would lean towards the Swoop Duo because I'm used to a 20" bike, but also noticed that there seems to be conflicting information on the gearing of that one. Tern's specs page says 48"-58", and Tern's store page says 29"-80". I'd have to assume that the latter listing is a typo talking about a bike with more gears, but I'm not entirely sure. Anyway, my Speed Uno is 64" for that, and I would be mildly disappointed if the Swoop Duo would be 58" and (in my limited understanding of it) go slower at the same RPM.
The Castro Duo (57"-69") seems like maybe it'd be better for higher speeds, and I have to admit that there are definitely times I'm jealous of the people passing me by on the road.