Quote Originally Posted by Catrin View Post
Thankfully they have ONE FS mountain bike with a compact double that is probably small enough for this purpose.
The term "compact double" doesn't apply to mountain bike cranks. A MTB double is almost always just a MTB triple with the big ring removed (and probably replaced with a bash ring.)

There are now some MTB cranks designed as doubles ever since SRAM introduced their XX race groupset. That's a 2x10 setup designed to save weight over a more conventional 3x9 setup.