Has anyone else experienced this problem. I know this was torqued to spec during a fitting. I have a healthy scratch in the post now. Have inserted a very thin piece of rubber and tightened-but still having the problem. What have others done-I am a bigger rider-6’ 174 lbs-but never experienced with previous bike P2K.
Would appreciate your help.
Darcy
Same size (but a little fatter). Same problem. Hadnt had the problem with 2002 Cervelo One (anyone want to buy it?). After getting sick of it, I just tightened her up real tight…probably too tight but it works. Nice scratch in the seatpost for me as well. Be interested to see what other solutions are out there.
is the shim still in place?
What is “torqued to spec”, I contacted Cervelo to find out what the spec was for my P2k and they didn’t have one. I finally settled for as tight as I could get it using one of those little allen wrenches without any kind of handle.
This is a carbon post, yes?
Have you checked to see that the post and the inside of the seat tube are both completely free of any grease or lubricant?
Do you still have/use the original small brass shim in the seat tube (goes between post and frame)?
this one always comes up a couple of times a year. First, no lube on seat post or in seat tube. Second, because you mentioned a scratch on the seat post, there is probably a spot of blow-thru or weld slag on the inside of the seat tube behind a weld. Inspect and file down the bump on the inside of the seat tube. Make sure there is a shim in place. If not, I can give you a sketch on how to make one. After you make sure the above are correct, I guarantee that you’re seat post will stay in place - e
sort of off-topic, but where do you get the thin-gauge brass for the shim?
You should be able to find shim stock at Home Depot. Copper alloy shim stock is fairly inexpensive and you can get it in a multitude of thicknesses.
Hobby shop is a another good source of sheet brass.
cervelo uses brass. you think copper shim would work equally well? isn’t it softer? or does it even matter?
Brass would work better in this instance as it is harder and is used constantly used in mechanical environments where interferences occur. The previous poster mentioned hobby shops for sheet brass. Brass would be your best bet if your post slides.
Made an assumption Tom-the torque wrench was set during and he tightened until it clicked. Figured he was going to a set target.
Darcy