Mavic Reflex came into being as a clincher and also a tubular:
http://www.mrrabbit.net/wheelsbyflemingapplications.php
Grab the spreadsheet...
Before you start, you need to decide where you are aiming depending upon the nipple and thread behavior:
http://www.youtube.com/watch?v=gCXFKN9JvCQ&feature=plcp
That video explains why you need to test the nipple you intend to use with the threads you will actually use as part of deciding on where you want to aim in terms of ERD.
Old school folks might still have 10mm standard profile nipple might and aim for the top. Modern day folks are typically using 12mm standard profile nipples and are aiming for the screwdriver flat or slightly above.
If you look at my spreadsheet I have the following for Reflex:
Tubular 610 SSD
Adding 2-3mm get you the screwdriver flat of a 12mm nipple or a hair higher.
Clincher 603.8 Flat of 12mm
Ciincher 605.0 Top of 10mm?
Here's what I roughly get:
Reflex Tubular + NR High Flange Front and Rear 3-Cross + 12mm Nipple
292, 292, 290
Reflex Clincher + NR High Flange Front and Rear 3-Cross + 12mm Nipple
12mm Nipple = 288, 288, 286
=8-)