CAAD10 Seatpost slipping

[DCilliams]

Every time I ride, the stock seat post on my 2014 CAAD10 slips. I took it to my LBS and they said the seat post has more play inside my seat tube than usual, suggesting a slight manufacturing defect. I made a shim out of a coke can and tightened the collar real tight - - despite that, it still slips a bit after 40 miles or so.

Any suggestions? Better collars out there?

Thanks!

[AngryScientist]

carbon paste

[batman1425]

^^ This. Throw some in your stem clamp while you are at it. Good insurance.

[DCilliams]

I used some. Still slips :crap:

[AngryScientist]

then you need a new seatpost, made to tighter tolerances. the fact that you could get a alu can shim in there is a bad sign. new seatpin time.

[54ny77]

new seatpost and a campy collar.

[velotrack]

then you need a new seatpost, made to tighter tolerances. the fact that you could get a alu can shim in there is a bad sign. new seatpin time.

I would say that if you can get a coke can shim, it's the wrong size post altogether.

[DCilliams]

It's the post that is stock with the CAAD10. I also used a Thomson Masterpiece. Same issue. Post is 27.2 and collar is 30.9. What post and collar do you recommend?

[ftf]

It's the post that is stock with the CAAD10. I also used a Thomson Masterpiece. Same issue. Post is 27.2 and collar is 30.9. What post and collar do you recommend?

I'd recommend getting in contact with Cannondale support, sounds like your frame was a defect from the factory.

[batman1425]

I would buy or borrow a good set of calipers and measure the ID of the seat tube and the OD of your two posts. It isn't uncommon to find combinations that are at the extremes of both ends, that when put together result in a slipping post. That said, you should probably figure out which one is the biggest contributor to the miss match. If the frame is way out, contacting Cannondale for a warranty claim is probably the next step.

If it is just unlucky tolerance combinations, bring said calipers to your LBS and measure a bunch of posts to find one that is on the wide end of 27.2

[batman1425]

No one brand of post tends to run wide (IME). You can measure 10 Thompson Elites and get 10 very different OD's that are close, but not quite 27.2. Same goes for all manufacturers. Provided the frame checks out, it will take measuring a lot of them to find one that will work.

[bianchi10]

How long have you have this bike? Did you buy said bike at this bike shop?

If you purchased from them fairly recently, I would be wondering why they weren't swapping it out as a warranty issue. Especially since the mechanic had just told you that yiu had more play than normal. That's not ok. If you are tight nine the seatpost collar down to spec, you should not have to worry about slipping, especially using a cannondale supplied seatpost. If it were an aftermarket post, I would suggest trying a new post, but that's not the case here if I'm understanding you correctly.

[DCilliams]

Thanks for the great feedback! I will try those suggestions. Unfortunately, I purchased the bike, like new, from the original owner who worked at a local shop. So the warranty route doesn't sound promising.

[DCilliams]

How long have you have this bike? Did you buy said bike at this bike shop?

If you purchased from them fairly recently, I would be wondering why they weren't swapping it out as a warranty issue. Especially since the mechanic had just told you that yiu had more play than normal. That's not ok. If you are tight nine the seatpost collar down to spec, you should not have to worry about slipping, especially using a cannondale supplied seatpost. If it were an aftermarket post, I would suggest trying a new post, but that's not the case here if I'm understanding you correctly.

Yeah, I bought the bike from a guy off of Craigslist who was moving overseas. He worked at a different shop than the one where I recently had the bike looked at.

[DCilliams]

I've had the bike less than 6 months.

[azrider]

time to go Roubaix on that shiz....

http://cdn.coresites.factorymedia.com/rcuk/wp-content/uploads/2014/04/12-IMG_7866.jpg

[bpm]

Has the seatpost always slipped, or is this a new development? If this is a new development, I'd be checking that frame and clamp pretty closely for damage of some sort.

[DCilliams]

To my knowledge, it's always slipped.

[Anarchist]

I had a bike where I had this problem all the time.

I finally figured out that the problem was actually the Campy seatpost collar. It was an "ah hah" moment.

When I actually looked at it what I saw was that the seatpost collar did not meet the back of the seat post, it wrapped around a bit and came together in a situation where one side of the collar was longer and was meeting the other piece before the collar had a chance to tighten fully.

This is hard to explain without a picture, but once I took a file to the "long piece" of the seat post collar and filed it down, the slipping seat post never happened again.

[sitzmark]

Try going back to shop where the original buyer purchased/worked. They'll have record or knowledge of the purchase. More than likely they will handle warranty if the seller's story (employee/bought there) checks out and frame is actually defective.

If the frame is defective first line of action should be replacement, not bandaids.

I had a defective Thompson Elite post that was machined wrong. It slipped every ride until I discovered the machining error. Called LBS were it was purchased and contacted Thompson. Long story - Thompson originally refused to take care of it. I had LBS call Thompson and then I sent the post back to Thompson. Management said post was over tightened. Disagreed repeatedly - irregular (not completely round) machining even where the post had not been inserted. After a few months of "fighting" Thompson finally sent me a new post. Problem solved.

[henrypretz]

Have you tried spinning the clamp 180* ?
Might change the interface enough to hold it?

[GregL]

Have you tried another style of seatpost clamp? The stock CAAD10 clamp is (I think...) a standard round, symmetric type with the bolt threading into the clamp itself. Perhaps an asymmetric clamp, with the bolt threading into a barrel nut, would provide a more even clamping force. I know that my CAAD9 and Six13 both use asymmetric clamps and have no issues with the seatposts slipping.

- Greg

[sitzmark]

Have you tried spinning the clamp 180* ?
Might change the interface enough to hold it?

Pretty sure can't spin it on a CAAD 10. Slots in one direction. At least thats what I recall on mine.

[Cicli]

Have you tried spinning the clamp 180* ?
Might change the interface enough to hold it?

Cannondale clamps have a pin that sits in the split of the seat tube. No spinning it.

[Anarchist]

The attached is close to what my Campagnolo collar looked like. It wasn't all grabbing at the same time. Once I spent some time with a file at the outside edge of the collar, right by the bolt head, and took a bit of material off there. It worked fine.

http://www.excelsports.com/main.asp?page=8&description=Seatpost+Clamp&vendorCode=CAMP&major=11&minor=11

The other thing to think about is that not all collars are created equal. I had a collar one time that was a thing of beauty to behold, two thin bands of material with a cut out section. It was really lovely. Problem is it didn't apply clamping pressure to hold the post without slipping. It needed the extra bit of material that was cut out for looks.

[DCilliams]

Thanks for the fast responses. I really appreciate the help. I managed to track down the shop he worked at (after about a dozen calls) and the guy there said to bring it in and they'd go from there - had no problem contacting Cannondale if there was indeed a defect. It's an hour drive away, but a worthy first step. If that falls through, then I'll try all the methods listed above. Again, much appreciated.

[oldpotatoe]

carbon paste

And knurl the post if it's aluminum.