mattkime

My seatpost on my CAAD10 keeps slipping. Its a Thompson Elite. I have the original seatpost clamp. I feel like I'm torquing on that clamp much harder than i should be and my seatpost is still slipping. Some options -

a) grease the seatpost clamp bolt and maybe a little bit on the collar (but not the seatpost!!). Maybe I'm suffering from the wrong kind of friction.

b) replace the seatpost clamp with another cannondale clamp. (size 30.9mm)

c) get a thompson seatpost clamp. 31.8mm is close enough to 30.9mm

Any advice?

dsbrantjr

Make certain that you have the proper size post, you will not be able to clamp an undersized post. You need to know the diameter within +/- 0.1mm.
If the slot on the post is getting clamped shut it cannot hold the post.
The clamp needs to be sized to fit the outer diameter of the seat tube, and no, 31.8mm is not close enough to 30.9mm

SkyDog75

On a CAAD10, you should be using a 27.2 mm seatpost and 30.9 mm clamp. It doesn't seem that a Thomson clamp would be an option since their nearest sizes are 29.8 and 31.8, neither of which is "close enough".

If everything is properly sized and the post is still slipping, you can use something like Ritchey Liquid Torque or any common carbon assembly paste between the seat post and seat tube to give you some extra friction -- hopefully enough to cure the slippage.

redlude97

I had the same problem with my CAADX, I ended up using a soda can shim and a surley clamp Slipping seat post fix: Epoxy a shim?

Wheever

Carbon assembly paste on the seat post might help. Depends on how loose the whole assembly is, however.

mattkime

The smallest reading i got out of my micrometer was 27.10mm for my 27.2mm post

Carbon paste seems to have helped thus far. Did a 25 mile ride and it seems to have stayed in place although I think a longer test is in order.