Cannondale Synapse Carbon 5 2015 seat clamp click

My 2015 Synapse does the same. As long as that isn't the sound of carbon cracking, I don't mind, though sometimes I've wondered if the seatpost was about to break off. I'm used to "Creakindales", my old T700 is prone to creaking too, I think from the giant aluminum tubes echoing the sounds.

thepiratebays.org I have no idea of it

I have the same problem with my 2016 Synapse Carbon.  Yesterday,  my bike shop took the wedge out, greased it heavily and put it back in.  The wedge is aluminum and rubs against the carbon...thus the creaking.  Seems one could be made of a hard rubber or acrylic as a solution.

  I also changed out my Selle Italia for a Specialized that I had from a previous bike.  The Selle was creaking and no amount of tightening could fix.  So far, since I bought the bike in Sept., it's been back in at least 6 times for creaking and once for the bottom bracket noise problem.

All is quiet today but I'm not optimistic.  Does anyone know if Synapse Alloy frames have the same problems?

I've got this same exact problem on my 2016 Cannondale Synapse Carbon. Does anyone know how to fix it? I tried grease, new seatpost etc. but nothing seems to work. Best result I got was when I dropped the seat by 2cm. Even then the wedge loosened after while and started clicking again.

Wait until the BB30 starts clicking/creaking/groaning - you won't notice the seatpost then. This comment is from one who knows

I went a bit overboard and used carbon assembly paste on the post and the bits of the wedge that grip the frame, but then used Park polylube 1000 (basically carbon friendly grease) on the two sliding faces of the wedge. Basically coating every surface in some sort of grease.

It sort of worked for a while, I've got countless creaks at the moment which may or may not be from the seatpost ...

Great bike, absolute chore to keep creak free

Carbon paste on the post and tightening the bolt tighter than what I was comfortable with cured that creak on my Synapse.