I have broken 3 P3c Seat Clamp bolts. I use Park grease and a torque wrench at the recommended 12NM. Am I doing something wrong or is this just a weak part? Can you use a normal bolt? Any other ideas?
The manual says 12Nm, but I can swear my P2C has 4Nm stamped into the bracket. (I’m not at home right now.) Is there a spec on your bracket or printed near the threads? That should override whatever might be in the manual.
Are we talking seat clamp bolts (at the top of the post) or seat post clamp bolts (where the frame enters the post)? If you torque the later to 12 nm, you’re gonna toast your frame.
I have a p2c and is 4nm (bolts where seat post enters the frame), there blue clamps and stamped this)
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OK, it seems like he might be asking about where the saddle connects to the seatpost. I just tighten that one until the seat doesn’t slip when I ride over speed bumps. Probably tighter than 12Nm…
How much do you weight?? I’m about 185lbs.
The seat clamp at the top of the post. It tightens the brackets to the seat rails. Not the 2-small bolts at the frame
I used super glue and tightened the shit out of it. No slipping problems anymore. The clamp is probably permanently attached, but that’s ok with me.
I also use the brown anti-seize between theparts that mate to the hole. Per Cervelo, if you don’t tighten to 12NM then the seat will tilt nose down as you ride and you will ruin the seatpost. The anti-seize is supposed to help prevent the slippage.
“The seat clamp at the top of the post. It tightens the brackets to the seat rails.The seat clamp at the top of the post. It tightens the brackets to the seat rails.”
as i recall, this is an old style seat binder type bolt, a male and a female bolt and nut that mate. again, this from memory, that part is very close to “bottoming out” right when it gets sufficiently tight. i believe on one fellow’s bike i had to grind down the male “bolt” terminus to make it a mm or so shorter, so that it would not bottom out. then it got the saddle nice and snug. my own p3, i did not have this issue.
i just wonder whether this might not be the issue with your bike. 20sec on a bench grinder solved this problem for this one fellow. i don’t want to speak out of turn, perhaps a cervelo person, chris bastie or sombody in tech support, might see this thread and comment.
I broke another one today. I don’t think this one was bottomed out. I was able to see threads thru the female side. This one was a campag binder bolt. They seem to hold until I make a saddle adjustment. I think they may be bending then breaking. Not sure what to do about it other than replace the binder bolt with a strong normal bolt.
Same problem here, I broke my first last week. The setup is in the fwd position with 1cm left on the rails of a fizik arione tri 1st edition.
Next binder bolt will be fitted with locktite. Keau
i have work with so many of these p3 and p2 and never had that problem. What is your weight?
150 lbs
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yep, get in touch with cervelo customer service. Perhaps you need a new set post and hardware. At 150 lbs…you should definitly never have any problem… i ride a lot on the saddle also and never had my saddle go down even when hitting big bump…that s about 3 years of cervelo riding and 1000s of miles…
I solved the problem by getting a new bolt and using a mid-length front brake nut that was just short enough to allow the seat bolt to be torqued to spec without bottoming out. The brake nut has a huge amount of threads to accept additional torque if needed. Works like a champ and should be standard on Cervelo.