# C50 seatpost clamp?



## lhart (Oct 25, 2005)

Any C50/C40 riders here that've had seatpost slippage issues?
I've got a 28.0 Colnago post that's sliding down the seat tube a bit, and while I've applied some Tacx Assembly compound, it'll still move a little after a few hours. I don't want to get crazy w/the seatpost clamp pressure on a carbon post.

So:
Has anyone here replaced the Colnago seatpost clamp w/the Campy unit? (maybe better clamping force?)
Anyone have any issues w/shimming a 27.2 post to 28.0? (kinda budget...)
Anyone using a Thomson Masterpiece 28.0 post?

I just want to deal w/this, it nags (no pun intended) at me.
Thanks in advance for reading/replies!


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## dnalsaam (Dec 6, 2004)

Turn the collar around with the opening facing forward and the writing saying Colnago facing the rear of the bike. It will overcome all slippage problems.


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## lhart (Oct 25, 2005)

Thanks for the reply, D!
Great rides and smiles to ya'.


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## campagnoloneutron (Sep 15, 2005)

lhart said:


> Any C50/C40 riders here that've had seatpost slippage issues?
> I've got a 28.0 Colnago post that's sliding down the seat tube a bit, and while I've applied some Tacx Assembly compound, it'll still move a little after a few hours. I don't want to get crazy w/the seatpost clamp pressure on a carbon post.
> 
> So:
> ...


I have had three recent Colnagos, Dream, C50 and Extreme and on all of them I have replaced the Colnago branded seatpost clamp that came with the frame. Reason for replacing is that I use carbon seatposts (FSA and Campagnolo). For any carbon seatpost you need a clamp that is engineered to equalize the clamping force so as not to crush the carbon seatpost. The Campagnolo seatpost clamp is specially engineered to do so. The Campagnolo clamp is not an expensive part to purchase but is well engineered to do the job. In my opinion Colnago cheaps out on continuing to supply a substandard part on a high end product when they should be doing the opposite. The Campagnolo seatpost clamp comes in a couple of different sizes; the correct one for C50 and the Extreme C is marked diameter min 31.6mm - max 31.9 mm (this because they are referring to the outside diameter of the tube to be clamped).

On the seatpost shim item; I have used a reducing shim on the C50 and Extreme to change it from 28.0 to 27.2 successfully for a couple of seasons. No problems with this whatsoever and it does give you a super wide range of seatposts to choose from. The USE shim is a good one that I have used, it is black, very unobtrusive and has a small lip which keeps it from slipping down into the tube. Again, I have to comment on the original Colnago seatpost that Colnago "recommend" for the frame. They produce/provide a seatpost in the proprietary size of 28.0 with their own branding at extra cost to the frame and while it looks cool, functionally there are lots of better ones out there, ones with better/easier adjustablity, better finish, lighter weight and for the most part they are less $.


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## Clevor (Sep 8, 2005)

campagnoloneutron said:


> I have had three recent Colnagos, Dream, C50 and Extreme and on all of them I have replaced the Colnago branded seatpost clamp that came with the frame. Reason for replacing is that I use carbon seatposts (FSA and Campagnolo). For any carbon seatpost you need a clamp that is engineered to equalize the clamping force so as not to crush the carbon seatpost. The Campagnolo seatpost clamp is specially engineered to do so. The Campagnolo clamp is not an expensive part to purchase but is well engineered to do the job. In my opinion Colnago cheaps out on continuing to supply a substandard part on a high end product when they should be doing the opposite. The Campagnolo seatpost clamp comes in a couple of different sizes; the correct one for C50 and the Extreme C is marked diameter min 31.6mm - max 31.9 mm (this because they are referring to the outside diameter of the tube to be clamped).
> 
> On the seatpost shim item; I have used a reducing shim on the C50 and Extreme to change it from 28.0 to 27.2 successfully for a couple of seasons. No problems with this whatsoever and it does give you a super wide range of seatposts to choose from. The USE shim is a good one that I have used, it is black, very unobtrusive and has a small lip which keeps it from slipping down into the tube. Again, I have to comment on the original Colnago seatpost that Colnago "recommend" for the frame. They produce/provide a seatpost in the proprietary size of 28.0 with their own branding at extra cost to the frame and while it looks cool, functionally there are lots of better ones out there, ones with better/easier adjustablity, better finish, lighter weight and for the most part they are less $.


I agree with the crux of your post. I too, am going with a USE shim on my C50 for two reasons:

1. Heard about the out-of-round issue with the inner diameter of the Colnago seat tubes. I'd like a shim between the post and tube to serve as a buffer zone to prevent damage to either. I will use a light coat of Taqc Dynamic Compound on both to prevent seizing.

2. The shorter 27.2 Record post will also shave weight over the porky Colnago. I believe the Colnago post is made by Selcrof.

I had also planned on a Colnago headset (Silva) but it looks like a toy compared to the Chris King. I decided to forego keeping the build all-Italia because of this, and will go with a CK headset and Phil Wood Ti BB. I'm going with what's the best in the business.

And based on your advice, looks like I'll be swapping out the Colnago seatpost collar too .


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## campagnoloneutron (Sep 15, 2005)

Sounds like a good plan for your build. I am just starting to build the Colnago Extreme in EITA color scheme and I am also planning on using a Chris King headset, a great product, just deciding on either black or silver. I may post a "build thread" on the Extreme as I did last year when I built the C50 in the NL38 world champion paint scheme. NO bottom bracket for me this time... going with the new 175mm ultra torque 2007 Record cranks.


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## Clevor (Sep 8, 2005)

campagnoloneutron said:


> NO bottom bracket for me this time... going with the new 175mm ultra torque 2007 Record cranks.


Some are probably wondering why I am installing a square taper crank on this dream C50 build. For one thing, I had been saving a 2003, hand-made Record crank - which I had purchased brand new on Ebay - for this build. Mainly I liked the unidirectional weave, which should match my Bora Ultras nicely . The crank is also very light for a 53/39 double (mine weighs 528 gms). However this crank is becoming somewhat of a collector's item as time goes on, and I feel it will gain value better but not having been installed at all. Mine is boxed with instructions and sealed crank bolts. Casran over at WW (who is an European Campy distributor), was just looking for one in my size.

Secondly, I couldn't resist picking up a 2006 Record CT crank from CC for $249, and since this is a square taper (which doesn't bother me in the least), this gives me an excuse to try a legendary Phil Wood Ti BB. Besides, this setup (with Ti crank bolts) should come in just under the weight of a 2007 Ultra Torque setup :thumbsup:.

Alternatively, I just found out that the ole Kooka Rasta ATB cranks will work on road bikes. It should weigh around 525 gms with 50/34 rings. I got two of them on closeout 10 years ago. The Rasta cranks come in rainbow colors of green, yellow, red, and blue, and should look very interesting on a WC frame :wink:.


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## lhart (Oct 25, 2005)

"Some Rabobank bikes ran with seat collars that were rotated such that the slot in the frame and the slot in the clamp were offset by 180 degrees. This was done to prevent crimping of relatively fragile (as compared to aluminum) carbon fiber seatposts."
via cyclingnews.com
http://www.cyclingnews.com/tech.php...ank_Colnago_Extreme_Power_reverse_seat_collar


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## KATZRKOL (Mar 4, 2004)

*Much a do about nothing. .*



campagnoloneutron said:


> I have had three recent Colnagos, Dream, C50 and Extreme and on all of them I have replaced the Colnago branded seatpost clamp that came with the frame.


The Campagnolo clamp is a POS, and everyone knows this who buys a Colnago. Quick fix: Buy a Campagnolo seatpost clamp. Beautiful!


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## crashjames (Jan 14, 2003)

KATZRKOL said:


> The Campagnolo clamp is a POS, and everyone knows this who buys a Colnago. Quick fix: Buy a Campagnolo seatpost clamp. Beautiful!


I'm confused - the Campy clamp is a POS so buy a Campy clamp to replace it? Or did you mean a Colnago clamp replaced with a Campy clamp?


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## KATZRKOL (Mar 4, 2004)

*Sorry!*



crashjames said:


> I'm confused - the Campy clamp is a POS so buy a Campy clamp to replace it? Or did you mean a Colnago clamp replaced with a Campy clamp?



Late work day low blood sugar thing:blush2: . Yea. Get the Campagnolo seatclamp. It works great. The Colnago clamp is a POS. .And kinda heavy too!


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