Joined: Jul 2015
Posts: 7,501
Likes: 3,302
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
the carbon bars FLEX and TWIST around in the two bolt stems... the four bolt stem will hold them in two places, and should eliminate the issue...
Carbon fiber BENDS and TWISTS... this is why we all love the ride provided by the CF frames.... same for the old steel tubed frames... aluminum is very stiff, and it rides rough. Once aluminum YIELDS to a load, it fails/cracks, or will, eventually...