I have purchased two of them and have them both here in the stable. One I ordered through my LBS from Merry Sales. It is the 26" version, the Mt Campee. The other I purchased from Alex's Cycles in Japan, and it is the 27F model which I think of as the 700c version.
The heights of these two racks are quite similar. By my reckoning the 27F measures 372mm from the center of the lowest attachment hole to the underside of the platform. The 26" Mt Campee is only slightly shorter at 360mm.
Both of these racks have the dogleg bent lower legs intended to reach to the fork tip eyelet below the fork tip. In the photos I've seen of the 650b sized one, the lower legs are straight , which appears to mean they should be attached to eyelets above the fork tip.
My Mt Campee is made of 10mm tubing. My 27F is made of 8mm tubing. The lowriders are identical and interchangeable, the outer hoop being 10mm tubing. Left and right are not interchangeable.
Bill Lindsay
El Cerrito Ca