Originally Posted by
Abu Mahendra
Wow, you want 20-100 gear-inches on a dereilleur drivetrain on 355 wheels? I don't have that range on my double crankset 451er. SRAM DualDrive may be just the thing for you. There's a reason it used to be speced on the Birdy Touring. I used to have 19-113GI on a 406er with it.
Have You given thought to dereilleur ground clearence? Anything beyond 1x11-36T is going to require at least a medium cage RD which, on a 44-355 wheel, is gonna be quite close to the ground.
Yes, I'm also considering dual drive. I heard the SRAM one is being discontinued, but Sturmey Archer also has one, anyway. More weight/complexity than a 1x11 setup, but smaller steps between gears. Again, harder to fix if anything goes wrong on tour. Might as well choose a triple crankset, then I don't have to build a new wheel. The original 9-32t cassette won't fit on a dualdrive, I'd have to use a Shimano-compatible 11t minimum.
The original Deore Trekking setup looks like a long cage to me, though it doesn't say: htt¤ps://¤
http://www.r-m.de¤/en-us/folding-bik.../#18B02_130411 (remove ¤ from url)
Yes, it's pretty low. I won't be riding offroad with it, but it's a risk.