Pedal Wench

I'm having a recurring problem with the saddle clamp on my Campy Record carbon seatpost - a 2004 model, from what I can tell. I've had the seatpost since June, probably put about 2000 miles on it. Recently, the clamp has been slipping, so the saddle starts to tilt back and up. I'll tighten it as tight as I can (CroMoly rails on my Specialized saddle) but after a while, it slips. I had to pull over three times today, and finally gave up. I was about to ride the last mile of my ride standing up. I had it pretty tight - actually had a strong guy tighten it up, but it still started slipping backwards again. It's pretty dangerous - starts subtly, but then really tilts back and practically tosses me off the back. Anyone have a solution, or at least a suggestion?

gcasillo

No solutions or suggestions, but I was scared away from those posts from the reviews it got on roadbikereview.com. Seems a fair share of folks have had problems similar to yours. I'm a Campy fanboy, but there's some things I won't mess with. My seatpost is one of them.

Pedal Wench

No problems with the actual carbon post, my problems are strictly with the saddle clamp. Those reviews were pretty scary, but not one had a problem with the clamp. I'm pretty gentle on bikes.

pigmode

Did you disassemble to inspect the index grooves? That was one of the parts I downgraded to Chorus. Did not know about the reviews, but the carbon head did not make much sense.

adamfresno

There was a recall on campy seatpost a year or two ago if I recall correctly. However campy should have a 3 year warranty I think.

Pedal Wench

The grooves seem to be rather shallow, and probably getting worse each time it starts to slip - I'm sure it just scrapes those away. It was a Performance purchase, so I'll let you know if they exchange it - I just want to prevent it from happening with the new one.

pigmode

I'm sure you already have this covered but... When you get the new post, make sure when you tighten the clamp down that the grooves are indeed fully indexed, and the curved piece above the hex is properly seated as well. The latter can be tightened down even when slightly out of position.

biker7

I too am a Campy fanboy but in general prefer a two bolt smooth interface clamp design to a single bolt serrated interface. Virtually impossible to get a two bolt to slip...competing bolt tension isn't going to budge and a smooth clamp interface is much more tuneable to precise saddle angle...critical to comfort IMO. 2 bolt clamps can be made virtually as light as well.
George

pigmode

I hear you. My Aliante is the best saddle I've ever had, but is also the most critical with positioning. But I have what I have and am commited to making it work, and am not one to jump around always searching for improvements. Not into accessorizing.

Pedal Wench

What is sad is that in my attempts to just get the darn thing to stay on there at all, I've been riding with the saddle in whatever position it is when I get the thing clamped on. Did the larger portion of a century last weekend with the nose so far down I was afraid I'd slip off the front onto the toptube - did the first part of yesterday's 45 with it still at an awful angle - I guess I'm not as particular about the positioning as I thought...

I had a two-bolt design on my Cannondale R1000, and I did not care for it. It seemed very tricky to get it positioned - as soon as I thought it was positioned properly, I would tighten it up and it would start to tilt either too far up or down. I thought I would be really happy with Campy's single bolt design, until all of this started happening.

You know, I might not have checked the positioning of the serrated grooves before I clamped it down, but it just started doing this after about 2,000 miles without ever touching it. Not sure why it would start to loosen up after all that time, but then again, I probably should have checked the tightness of the bolt occasionally.

Pedal Wench

Hmmm, do you think a lock ring on the bolt would keep things from loosening up?

biker7

Your answer is in the dynamic that is occurring. If the bolt is retaining its initial tightening torque and your seat is changing attitude then a lockwasher...star or thrust washer won't help. If bolt torque is being retained the serrations are either worn or rounded or inadequate to support your weight due to vibration etc. Running the clamp on the far side of seat rail travel will test it more. If the seat angle starts to change if the bolt loosens...try some loctite 242 on the threads and/or a washer as you noted.
The dillemma or design tradeoff for a serrated single bolt seatpost is adjustability versus retention. In an effort to provide more precise adjustability, mating clamp serrations are made more fine. This can cause slippage if the serrations aren't just right or are not engaged fully when tightening. Slippage is aggravated of course by higher rider weight. Big serrations for better engagement isn't acceptable because will not afford precise enough saddle angle adjustment. A two clamp design is not encumbered with this tradeoff. Biggest challenge for a 2 bolt clamp is weight. Again...2 bolt clamps are the ticket if you want more precise adjustability and a more secure attachment. Can you tell which I prefer?
HTH,
George

pigmode

Shouldn't need one, nor do you need a "strong guy" to tighten it up for you. Your post was either defective, or it sustained damage due to being ridden while being improperly seated.

Pedal Wench

I'm hoping it was just a defective clamp, and not higher rider weight, as you suggest. If it can't handle about 120 lbs, Campy's got more serious issues going on! If the new one has similar issues, I'll go back (reluctantly) to a two-bolt design. I have a Bianchi seatpost on my other bike that I can use in the meantime. Doesn't look as nice as Record, but not much does...

biker7

A buck twenty?...what is that? You aren't one of those guys that flies up the hills are you? Serves you right to have clamp problems
George

Pedal Wench

Ha! Nope, just a woman who crawls up the hills! Now, quit being mean! (Jeez - I thought my user name was pretty unambiguous...)

biker7

Unambiguous?...lol. Funny, I thought the same thing about your technical question.
You're welcome for the advice.
George

pigmode

For some reason I thought you were Pedal wRench. I asume you have a new post on the way already?

Pedal Wench

This is what I get for trying to be clever...

Yeah, the seatpost is on its way back for exchange. I'll let y'all know how it works out. I'll make sure that it's properly 'seated' in the serrations before I tighten it up. Thanks for the suggestions and help!

pigmode

Don't forget the form fitted piece above the hex (if the Record has one, as does the Chorus). It must be seated properly as well, with no visible gaps.

bvfrompc

This happened to me on my mountain bike, an hour and a half into a 3 hour ride.

There are two things you need to do.

#1 While on the ride, take a patch and place it between the clamp, it will help hold it in place. We tore a small hole in the middle of the patch for the bolt to go through and then clamped the sucker down. It held for the rest of that ride and until #2 played out.

#2 When you get home, grab a catalog and order yourself up a two bolt clamp. You only have to set the dern thing once in a lifetime, maybe twice if your not already sure what angle you like your seat. It may take 15 minutes of fiddling, but thats a lot better than your seat slipping on a great 60 mile ride.

I felt like mcguiver with the fix, very cool.

Pedal Wench

Someone suggested a Thompson Masterpiece seatpost. Biker7, do you think it would 'go' with a Bianchi/Campy setup? Hate to lose OCP points! Seriously, any thoughts on that clamp?

biker7

Hi Pedal Wench,
The Thomson Masterpiece is just that...a masterpiece IMHO...the nicest alloy seatpost out there....again my opinion but shared by others as well. I have the Thomson Elite on my Campy equipped Biachi which is only a few grams heavier than the Masterpiece and certainly lighter than the factory Bianchi single bolt offset seatpost I removed. I can go on and on about the engineering behind it but will spare you. The Masterpiece is quite a bit more money so for 40 grams more in weight I prefer the Elite. The Elite/Masterpiece comes straight or with offset which they achieve unlike other posts by having an elbow in it approx. 80-100mm down from the seat clamp to rail interface so you would have to measure your bike for suitability to ensure you are running enough straight post to accomodate the elbow/offset. The other thing is the Thomson offset post has only a modest set-back...only a bit more than 1/2" or so and hence some prefer a different post for more offset. Again if you don't need offset, simply purchase the Thomson straight post. Also measure the length of post you need. I modified my Elite because I wanted about a 280mm post total and Thomson sells in 250 and 330mm lengths so I purchased the 330 length and cut it down. Below is a pic on my bike with a Brooks B.17 I ride a lot of time. The biggest factor over and above your existing challenge of staying in position which a two bolt clamp excels at is... adjustability....where the Thomson shines. Seat angle for me is critical....a balance between perineal pressure and sliding forward. I can dial in precisely the angle I need which greatly improves riding comfort.
Thomson posts are available on e-bay all the time and a nice if not almost new example will go for about one half of retail...where I picked mine up. Lastly, your question about how would a Thomson post 'go' with a Bianchi with Campy...is a good one and something we all consider as we change parts on our bikes.
I guess my response would be...the performance is so good with the Thomson and the post is so beautifully made and superior to the Campy post, it wasn't a difficult decision...it clearly goes with the bike as any nice upgrade would.
HTH,
George

sydney

Thanks for that.It would likely be right up there with the blather about ratchets working on friction.....

biker7

Blather to you because you are the village idiot of BF.
George