I'm pretty sure 21.1 is the quill diameter. BMX standard which is being phased out on nicer BMX bikes. Also older, usually cheaper road bikes. A few early 80s MTBs. A lot of old Schwinns, etc.

The sunlite looks to be at least a 30mm extension to me.


Remember stems are measured from quill centerline to bar centerline. A 21.1mm length stem would have a 25.4mm bar and a 22.2mm quill intersecting each other.

12.7 + 11.1 = 23.8mm (this would be a stem length in which a 25.4mm bar and a 22.2mm quill are touching.)

For the OP, assuming 26.0 bar clamp,

13 + 11.1 = 24.1mm