Originally Posted by
twocicle
I found the exact opposite to be true... that stems with more surface interface area hold the steerer better than those stems (ie: 3T ARX) with less gripping area. This should make rather obvious sense. I have had zero slip problems with Ritchey 4-Axis stems @ the mfr torque spec, whereas the 3T ARX was problematic. You can augment the stem grip by using carbon grip pastes. So there you have it... two solutions to zero for your LBS.
I use carbon assembly paste. It's a carbon steerer after all. One of the stems I tried was a Thomson with a greatly cutout contact area. That worked better, but was a 0° stem and I wanted a 17° drop. The best stem so far is an Eleven81, which has a short body, about the same as the Thomson and is 17°. I stacked washers on top of it to make up the difference. It's possible that the increased PSI from the lower surface area helped, or that it does not grip the steerer in the worst worn area. Anyway, that's what works the best.
I have a ~.5mm plastic washer between stem and top cap. Should there be another, thicker washer? If so, what would it do?