Bill,
Thanks for the quick reply.
Looking more closely at photos of the 27F, it appears that there is an integrated spacer at the mounting point of the rack, facilitating clearance at the fork blade when mounting from the below axle fork eyelets.
Is this accurate?
I had imagined that all the holes in the rack legs were useable with a non integrated spacer, so in switching from 700c to 650b one would use a different mounting hole, allowing for some adjustability of the platform to tire distance.
In your experience, does this seem feasible?
Much appreciated,
James