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Discussion Starter · #1 ·
On the other thread there was some mention of the Carbon Rush not being compatible with carbon seatposts and I was wondering what the story is on this. I checked both my printed catalog and Cdale's website, and they picture the Carbon with Carbon Cdale or FSA posts, but now under the specifications it lists the seatposts on all the models as the Thomson Elite 410mm, which I have on my 800 and a very impressed with. Are there any strength or size issues here that have only now been discovered?
 

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LA CHÈVRE
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According to a Velonews or Cyclingnews article on the carbon Rush (cannot remember which), it's not incompatible but rather that Cannondale just changed because they say too many users over torque seat collars with carbon posts... and you can't break a Thomson Elite.
 

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Discussion Starter · #3 ·
All I can say is I love my Elite and it is the best upgrade I have ever made on a bike. Well, good to know it wasn't due to any problems with the frame breaking or anything like that.

I was wondering, is the Thomson Elite with setback much weaker than the standard straight seatpost?
 

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bi-winning
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TalonSL said:
All I can say is I love my Elite and it is the best upgrade I have ever made on a bike.
Can you explain that statement? I don't really see any major advantages to a seatpost upgrade. My stock post clamps the saddle rails pretty well :confused:

A clipless pedal upgrade leads to more power. Brake upgrade results in better control of your stopping. Drivetrain upgrade leads to crisper shifts. What does the post do?
 

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USED2COULD
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rkj__ said:
Can you explain that statement? I don't really see any major advantages to a seatpost upgrade. My stock post clamps the saddle rails pretty well :confused:

A clipless pedal upgrade leads to more power. Brake upgrade results in better control of your stopping. Drivetrain upgrade leads to crisper shifts. What does the post do?
I think Talon had problems with his oroginal post flexing...
 

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Discussion Starter · #6 ·
Yes, my original stock FSA 270 flexed horribly, sometimes even more than a quarter inch. The Thomson just feels much better, more efficient with less flexing, safer, and that slick glossy black finish looks sweet. :)

Before I upgraded, the bike made this odd clicking clanking noise which I eventually discovered was the seatpost and seat tube flexing.
 

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I can.

rkj__ said:
Can you explain that statement? I don't really see any major advantages to a seatpost upgrade. My stock post clamps the saddle rails pretty well :confused:

A clipless pedal upgrade leads to more power. Brake upgrade results in better control of your stopping. Drivetrain upgrade leads to crisper shifts. What does the post do?
After bending, breaking a few posts, I upgraded to a Thompson 27.2x440 (2001-2002). It has been on each of my dale's, and currently supports me on my Gemini. By far, THE BEST plug-and-play part ever. I will NEVER use a different post. it is not worth it.

I am 235lb or so, and run it WAY long because of the 35" inseam.
 

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Discussion Starter · #8 ·
And remember, upgrading other components does not always lead to better shifting, braking, etc because many of them are only aimed at cutting a few grams of weight, which can sometimes be a bad thing because it can lead to increased failure. The seatpost is a great example of this, and the FSA 270 was just too light and shaved down for me that it had the problem. Sure, the Thomson is a bit heavier, but definitely worth it. The cranksets are the same, and many here love the XT over the XTR, Race Face, etc because they are just more durable.

I myself have a 36+ in inseam and weigh almost 200. My seatpost is set so high on my Rush it looks ridiculous.
 

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Ok, i see where flexing would be a problem if you combine all of; 200+lbs, lots of extension, and a small post diameter.

Personally, i am ~150lbs, and have a 30.8 post, with "normal" extension, so, it feels pretty stiff. I would like a few g of weight savings, and would happily accept a thompson, but, I simply would not notice a large difference like you did Talon. Thanks for the explanation.
 

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Discussion Starter · #11 ·
damion: Here's a pic of my Rush with the ridiculously high seatpost. It's pretty extreme, and I still feel a slight amount even with the Thomson, but it is barely noticeable. When I was first looking at bikes I almost went for the Prophet instead for this reason even though I never do anything aggressive enough to need one.



rkj_: I know what you mean about being lighter, and I really wish I was lighter and didn't have such an excessive inseam. When they measured me to build my road bike my inseam was 36.67 in! It's much nicer to be of smaller stature if you're into cycling because you can ride a smaller frame and use lighter parts to save weight. Most of my weight is due to my height, plus I also have heavy bones because I am way too skinny for someone of my weight.
 

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Just a bit of extra info on these 2 seat posts. I happen to have both seatpost in the same place at the same time there was a postal scale available.

The Thomson (410mm x 31.6) was 10 grams lighter than the FSA (350mm x 27.2).
 

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Discussion Starter · #13 ·
wv_rider said:
Just a bit of extra info on these 2 seat posts. I happen to have both seatpost in the same place at the same time there was a postal scale available.

The Thomson (410mm x 31.6) was 10 grams lighter than the FSA (350mm x 27.2).
Wow, that's pretty sweet, so no weight penalty after all! A much better and stronger seatpost with no compromises! And isn't the 31.6 heavier than the 27.2?
 

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wv_rider said:
Just a bit of extra info on these 2 seat posts. I happen to have both seatpost in the same place at the same time there was a postal scale available.

The Thomson (410mm x 31.6) was 10 grams lighter than the FSA (350mm x 27.2).
The carbon Rush stays with 27.2, so that means that the Thomson is even lighter!!!

Please say it isn't so....I added 10+ grams by keeping the FSA?.....what kind of weight compulsive psychopath am I? I have let everyone down!!!!
 

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Discussion Starter · #15 ·
trauma-md said:
The carbon Rush stays with 27.2, so that means that the Thomson is even lighter!!!

Please say it isn't so....I added 10+ grams by keeping the FSA?.....what kind of weight compulsive psychopath am I? I have let everyone down!!!!
Plus the Thomson was a 410 mm vs. the FSA at 350 mm. ;)
 

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Dan Gerous said:
According to a Velonews or Cyclingnews article on the carbon Rush (cannot remember which), it's not incompatible but rather that Cannondale just changed because they say too many users over torque seat collars with carbon posts... and you can't break a Thomson Elite.
Yeah thats mosty the issue. The agents here recommend the same thing.
Over torquing a carbon frame with a carbon post in it would probably have a greater chance o failure since neither frame nor ost enjoy excessive compression forces. I've seen some road frame crack near the seat tube / top tube junction because of overtightening.
An Aluminum post just resists compression better and you can't break it :thumbsup:

Personaly I 'm still not sold on the Carbon Rush but it is growing on me...
 

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Discussion Starter · #18 ·
Brad said:
Yeah thats mosty the issue. The agents here recommend the same thing.
Over torquing a carbon frame with a carbon post in it would probably have a greater chance o failure since neither frame nor ost enjoy excessive compression forces. I've seen some road frame crack near the seat tube / top tube junction because of overtightening.
An Aluminum post just resists compression better and you can't break it :thumbsup:

Personaly I 'm still not sold on the Carbon Rush but it is growing on me...
Makes sense, and good technical explanation. I agree about the Carbon Rush too, and this has me concerned. I will readily admit, however, that there's a large part of me that's simply jealous that I can't afford one despite having an aluminum Rush plus another being built. It is slowly growing on me, but I think I'll give it a year or two to prove itself before I seriously consider it, and I would most likely buy one if I had tons of money. Still, that Ibis Mojo or Yeti ASR-SL looks pretty sweet!:D
 

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TalonSL said:
Makes sense, and good technical explanation. I agree about the Carbon Rush too, and this has me concerned. I will readily admit, however, that there's a large part of me that's simply jealous that I can't afford one despite having an aluminum Rush plus another being built. It is slowly growing on me, but I think I'll give it a year or two to prove itself before I seriously consider it, and I would most likely buy one if I had tons of money. Still, that Ibis Mojo or Yeti ASR-SL looks pretty sweet!:D
I like what Titu have done with the Racer-X. They fitted a carbon crash plate on the downtube to take the abuse. Thats a clever bit of marketing and I hope Cannondale offer a similar solution for the 2008 Carbon Rush.
Also A Flythrough seatpost would be great and reduce weight for us competitive types who never drop their seats.

Is a Thompson Elite stronger? Oh yes it is. The Lay post is machined from a solid billet of Aluminum, not bent into shape. Also the internal wall thickness is greatest along the plane f bending i.e. the front and rear of the post are thicker than the sides.
And it's stil very light.
I have one on my Rush and I can feel that it's a lot stiffer than the FSA it came with. So when I'm hammering in the saddle, I don; find my wriggling from side to side to stay over the pedals. The Thompson is that stiff.:thumbsup:
 

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Okay, here's the real deal. Disclaimer: I'm Doug, and I'm a Cannondale dealer.

1. For the Carbon Rush, Cannondale stuck with a 27.2 seatpost, as they have with virutally every bike, save for the Synapse Carbons, SystemSix and Caffeines, which are 31.6;

2. Rush bikes have tons of standover with the curved top tube. Weirdly, but appreciated by us big boys, the larger sizes have better standover than the smaller sizes;

3. A nifty thing Cannondale prints on the back of the Carbon Rush's seat tube is a minimum insertion line, just like they do on seatposts themselves. Cannondale (smartly) wants to make sure there's enough post inside, just like the seatpost guys;

4. With a lot of standover, and a minimum desired seatpost insertion of ~4" (I haven't actually measure it, but it's fairly long), you're gonna probably want to spec a 400+mm seatpost...but it has to be 27.2;

5. There ain't that many 27.2 x 400 carbon seatposts out there...they tend to max out at 350, as previously mentioned...and those few longer ones that exist don't have any track record;

6. Thomson makes some of the lightest and strongest seatposts, in tons of diameter and length options. And yes, as we all know by now, they are alloy. And yes, they make a 27.2 x 410mm. They're proven, sought after, fairly chi-chi/boutique-y;

7. It doesn't hurt that Thomson is a eastern US-based MFR..

Given all that, it was a pretty smart spec by Cannondale. Even if lots of folks want (or think they want) carbon doo-dads all over their bikes

So now you know.

Doug
 
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