Joined: Jul 2015
Posts: 7,465
Likes: 3,281
From: NW Oregon
Bikes: 1982 Trek 930R Custom, '91 Diamondback Ascent w/ XT, XTR updates, Fuji Team Pro CF road flyer, Specialized Sirrus Gravel Convert, '09 Comencal Meta 5.5 XC, '02 Marin MBX500, '84 Gitane Criterium bike
your chain might be too tight... the freewheel is complaining, or the chain is complaining.
the tightest spot only happens when the two sprockets match at their respective tightest, most out-of round, places.
try loosening the chain adjustment a little bit.
other than that, i'm no fan of GXP bottom Brackets... they tend to wear faster than most others... a Scott CX Bike i wrenched on went through one every 3 to 6 months, repeatedly... the bike was also his daily ride, 85% of the time.