# C-40 seatpost- contingency planning



## boneman (Nov 26, 2001)

On vacation last week on the SE coast of Massachusetts near New Bedford. Took my C-40 and Corrado up to do some rides in the Dartmouth, Westport and Little Compton, RI area. Given that I'm shipping out to Shangha at some point, I figured I'd better be getting use of the C-40 before it goes into storage.

Coming back from a 55 mile ride, I went across a bump at about 23mph, heard a crack and suddenly my saddle was not exactly attached to the post. The front bolt, the one with the tilt adjuster nut on the Colnago carbon post, had sheared. Last 7 miles were done out of the saddle. At 131lbs, I'm not exactly a Clydesdale so I'll just chalk it up to metalIurgical failure. Called around, not too many options in that part of the World, and no one had a new post in stock. Chicagoland had them but would only ship via an internet order and given that it was a summer beach house, no connectivity nor computer. The 28.0 size certainly limits one's selection and finding an appropriate shim on short notice also turned to naught. Good thing I brought the Corrado as back up.

I kept all the parts and when I finally got home on Sunday, took out an ITM Millenium post I wasn't using. At the end of the day, the Colnago post is made by the same firm making ITM and Selcof. I had to file off the round ridge by the nutted section and then turn down the barrel a bit to get it to fit through the top part of the Colnago post but I'm back in action. Finding a replacement bolt, well certainly not at your local hardware store. I'll email ITM and Selcof to see if I can get a replacement shortly. In the interim, I've ordered a shim so I can use a 27.2 post in the event this happens again. Probably just a one-off issue and it's only the third component (excluding tires/tubes/tubulars) that I've ever had fail on a ride in 40+ years or riding. The others were a Shimano Crane (Dura Ace) rear derailleur whose forging by the drop out attachment bolt sheared and a broken rear derailleur cable.


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## KATZRKOL (Mar 4, 2004)

*Here Boneman!*



boneman said:


> Called around, not too many options in that part of the World, and no one had a new post in stock. Chicagoland had them but would only ship via an internet order and given that it was a summer beach house, no connectivity nor computer.


Don't buy from Chicagoland. .They suck and rip people off. You need a Colnago Seat-post shim, and then you can use ANY 27.? post you want!

Here's a link:
http://www.totalcycling.com/Product...yID/83/v/02abbfb2-890a-4073-b8bf-40b7614af359


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## boneman (Nov 26, 2001)

*Thanks*

I thought about Total but ended up buying a USE shim from Competitive Cycling in Little Rock.



KATZRKOL said:


> Don't buy from Chicagoland. .They suck and rip people off. You need a Colnago Seat-post shim, and then you can use ANY 27.? post you want!
> 
> Here's a link:
> http://www.totalcycling.com/Product...yID/83/v/02abbfb2-890a-4073-b8bf-40b7614af359


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## Number9 (Nov 28, 2004)

Any chance you overtightened the bolt or do you think it was simply a latent defect, either in materials or manufacture? Not an accusation - just curious as all four of my road bikes use the same seatpost (Pinarello seatposts and Colnago seatposts appear to be the same except for the OD & logo).


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## boneman (Nov 26, 2001)

*Possible but doubt it*

I only use a torque wrench when working on suspension or engine related things on my car. That being said, I've never had a bolt fail, on a bike or car, by shearing in a tensile manner. I've also have the same design, ITM and Selcof, that I've run for thousands of miles with no issue. None of this means I didn't overtighten.

I'm not worried about it, just pointing out the oddity of the 28.0 size, and how the replacement is not readily available.


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## toast (Jan 6, 2005)

*In case you don't know*

Thomson does make the masterpiece in a 28.0

http://www.lhthomson.com/masterpiece_sizes.asp



boneman said:


> I'm not worried about it, just pointing out the oddity of the 28.0 size, and how the replacement is not readily available.


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## boneman (Nov 26, 2001)

*Interesting*

I didn't know that. I need a post with set back so it wouldn't work. Wow, those bad boys are not cheap, only a few more for a replacement Colnago although from the Thomson's I've seen, I'd not worry about breakage. Thanks for the tip.



toast said:


> Thomson does make the masterpiece in a 28.0
> 
> http://www.lhthomson.com/masterpiece_sizes.asp


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## toast (Jan 6, 2005)

*Know this too*



boneman said:


> I need a post with set back so it wouldn't work.


Look again, that page has both the set-back and regular listed for 28.0. Both at the same low price.

SP-M103 28.0 diameter by 240mm long 154 grams

Setback Seatposts
SP-M103SB 28.0 diameter by 240mm long 154 grams

(I have been specking out a new c50, so I have looked into these things...)


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## Monty Dog (Apr 8, 2004)

The Colnago carbon post is made by WR Compositi - who also make Pinarello's - they do a full range of components as well - been using their stem and seatpost on my Colnago for a few years.


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## boneman (Nov 26, 2001)

*Not sure about that*

I was in living in Europe since the beginning of 1999 and WR Compositi made some interesting stuff but their posts back then were not great. They were known as a weight weenie machine shop. All of the stuff was CNC'd, eventually getting into CF with their stems. Their posts until recently in no way resemble what Colnago uses for the C40 and C50, then and now.

I was using a Selcof post long before ITM came out with the Millenium post and it used the same cradle and two bolt adjustable system as the C40 post. I'm not familiar with the Pinarello post and have no view on that product.

That being said, having done business in Italy, land of the cottage industry, anything is possible. 



Monty Dog said:


> The Colnago carbon post is made by WR Compositi - who also make Pinarello's - they do a full range of components as well - been using their stem and seatpost on my Colnago for a few years.


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## Number9 (Nov 28, 2004)

The Pinarello and Colnago CF posts appear to be identical except for outer diameter (both are spec'ed in nonstandard sizes though) and the logo. Both have an 8 N.m maximum torque spec marked by the front bolt. Adjusting the front bolt is a pain with the post/saddle in situ, but apart from that problem, they seem to be decent seatposts.


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## Monty Dog (Apr 8, 2004)

Boneman, disagree - my WR Compositi post and stem are identical to the Colnago and Pinarello ones on club mates bikes - are you sure you're not thinking of PMP? Check out: http://www.competitivecyclist.com/z...=34&PAGE_NUM=3&PRSET_VERSION=1&TFC=TRUE&MODE=


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## boneman (Nov 26, 2001)

*Md*

I'm not saying that WR are not currently not making them for Pinarello, or Colnago for that matter. But I don't recall WR doing these types of post until the last couple of years. I'll have to go through some back issues of Cycling Plus, Cycle Sport and Procycling. Truth is, I don't think that WR's a manufacturer but again, anyone who can tell what goes on with CF manufacture in Italy will hit it for 6.

Bank holiday weekend in the States and I'm away so it will keep until next weekend. The other option is that six years of living in London pubs has softened my brain or simply that I've gotten CJD during my stay in your fair Isle.


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## divve (May 3, 2002)

May also be the cause of insufficient tightening. Bolts don't deal too well with bending stresses. Sufficient tensile load will greatly reduce that type of fatigue.


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