I spied on the
Cruzbike blog a close-up of the boom holding the bottom bracket.
The new T47 bottom bracket means I can no longer use my short (152mm) square taper triple crank (used as a double). I'm not sold yet on 1x drivetrains, so currently I get the low gearing by running a 26t small front chainring with a 11-32 cassette. This works surprisingly well in combination with a 50t large chainring, and SRAM Red 22 shifters.
One of the few short cranks that seems readily available that might work is the Rotor ALDHU crank, which comes in 150mm and 155mm crankarm length options, and offers a 46/30 chainring option. With that, I would need a 11-36 or 11-39 cassette to get gearing that is equivalent to what I currently have. Or I could get a 1x drivetrain with a 10-52 cassette.
The 2x options tend to be a bit heavier than 1x unless I get away with SRAM Red shifters and an ultralight 11-32 cassette, and a really small front chainring, but that would require converting a triple crank into a double, and modifying the crankarms to be shorter. Finding a suitable crank that is not square taper, and suitable chainrings, so far seems challenging, which is why the Rotor crank seems so far one of the best options for what I want.
Another contender might be the cranks from White Industries with the 30mm spindle. They offer a wide range of chainrings down to 24 teeth, but the arms would need to be shortened.
Did any of you already consider this, and what short crank/low gearing option would you get for the V20c ?