Originally Posted by
dsbrantjr
I would suggest setting it up to use the big and middle positions of the shifter and letting the cable go slack if accidentally shifted into the small position. Trying to lock out the big ring position with the high limit screw can result in jamming or damage to the shifter if attempting to shift against the stop; having a slack cable will do no damage.
It won't damage anything and avoids having 3 clicks and 2 gears. The limit screw would just block the shifter engaging the big chainring.
I've ridden for 6 years with a 11sp mountain bike shifter with a 10sp cassette and the last shift blocked with the limit screw without any issue.