Use a fish scale...seriously!
I replaced the steering stem bearings on my last bike (cbr1100xx); the manual described the correct tension as a certain amount of pounds of force to move the bars from rest. The way to determine that was to suspend the front of the bike, turn the bars all the way to one side, attach a fish scale (no joke!) to a certain spot (can't remember right now if it was the bar end or a spot on the triple tree...), then gently pull while checking how much the fish weighs. If it weighs between (I can't remember exactly, but this is an example) 5 and 7lbs, the tension is set correctly!
Even though I went from ball bearings to tapered rollers, that scale seemed to do the trick...I could finally take my hands off at any speed, and the bike was stable from 0-160mph. :-)
Not sure if there's anywhere that Suzuki publishes that kind of info...
2004 V-Strom 1000 (currently broken - parts received - repairs in progress - snag hit - repairs on pause - unsnagged - repairs in progress)
Two Brothers with P1 tips, PCIII USB, SuperBrace Fork Brace, K&N filters, ROX bar risers, Kappa top and side cases, MadStad, Givi tall windshield, Givi engine guards, Sargent Seat, 12 volt air compressor, 530 Conversion, 17/44, SpeedoDRD, Rudolph Nose and Antlers