Pake C'mute comes in a 47 frame. Standover says 29.5 but that's with thicker tires. If you're riding without brakes, there's always the option of just putting 650 wheels on the frame. It's been done before.

Also, in general, 'Track' bikes will have a shorter top tube than road/commuter bikes.

http://www.pakebikes.com/product/F8EF09/C%27Mute+Frame