Measuring is easy, it's just crank/bottom-bracket center to rear axle center, and directly between those points, not horizontal distance at ground, that's something else. Just a tape measure needed. I think you mean to ask, does anyone have a BF Tikit, and would they measure the chainstay length (and make sure you describe)? If all else fails, you could try calling or emailing Bike Friday at their mothership and they could probably look it up for you in a minute.