Originally Posted by
glye
Hi! I want ca. 1.6 to 8 meters advancement, or in Sheldon Browns very sensible gain ratio, ca. 1.45 to 7.3. This assumes 175 mm cranks and 44-355 tyres. With a 52t chainring the e*thirteen 9-46 cassette provides this. SRAM 10-42 cassettes also work, if I go down to 48t chainring and sacrifice some high end gearing. The crucial question is frame clearance.
The original 9-32 cassette is much too narrow, but with a double crankset it should work (though 52-36 is a big jump). I have a 56-42-32 triple on another bike, that would be nice here too, with the original cassette.
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.