I have noticed my seatpost is slipping about 1/8" every time I ride it. I marked the height I ride with a black sharpie, so I can tell how far it is going. I am riding a USE alien carbon and am leary about tightening too much to damage the post. Any idea how to stop the slipage? I really am not a big fan of their seatpost securing method.

I do not have the problem on a 381i. I tightened it down and there is no slippage. But then again, I am using an aluminum ITM post. I suggest that you send an e-mail to USE. They may tell you the best way to fix the problem. A couple of years ago, one of the pro teams(CA I believe) was using the 381i and the USE post. So someone may have an answer for you.

I have noticed my seatpost is slipping about 1/8" every time I ride it. I marked the height I ride with a black sharpie, so I can tell how far it is going. I am riding a USE alien carbon and am leary about tightening too much to damage the post. Any idea how to stop the slipage? I really am not a big fan of their seatpost securing method.

Try some hairspray. Sometimes it provides just enough tack to prevent the post from slipping

I had the same problem with a Thomson Elite in my KG486 frame. I just inserted a thin plastic strip between the seatpost collar and clamp - no más problemas!