I have a 2010-2013 Cervelo P3 TT bike. It works great except the seatpost keeps slipping. I have added carbon fiber grip paste, I've tightened the seat clamp to 5 Nm, I've lightly sanded the seatpost, I've checked that the bolts are going in correctly, and I fashioned a shim (as pictured) out of some brass sheets. The seatpost hasn't slipped (yet) with the shim, but I've not done a full ride yet. There is still a giant gap on the side between the frame and seatpost. I tried to do a horizontal shim (instead of vertical as pictured) and it slipped with very little pressure. MAYBE the current shim will hold, but I'm not holding my breath. What are my other options?
Solutions for slipping seatpost (aero carbon, older TT bike)
byu/AStruggling8 inbikewrench
by AStruggling8
1 Comment
I had the same issue on my 2012 P2 back in the day. I took the aluminum clamp off and milled off about 1mm so there was a tiny gap between the clamp and the frame when it was torqued up. Never had a problem ever again. If you dont have access to a milling machine you can use a file and some elbow grease. Just make sure you torque the bolts a little bit at a time equally. I didnt care about the gap on the side.