# What is "ISP" carbon?



## armstrong (Jul 9, 2013)

I see some carbon bikes advertised as such. Is this a good thing?


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## Typetwelve (Jul 1, 2012)

Integrated seat post?

I'm pretty sure it's a frame where the seat post is actually part of the frame and when you get it, you cut it to exact length and then stem it for seat mounting. Honestly...seems like a pain in the ass to me...


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## Sundog (Sep 25, 2013)

Integrated seat post. Courtesy of Google. I didn't know either.


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## PJ352 (Dec 5, 2007)

As others have stated, integrated seat post. There are variations in design, but it's essentially a seat tube designed to function as a post, holding the saddle in place. 

Since saddle height is pretty unique to individuals even when frame size is similar, the disadvantage is that once the tube is cut, saddle height is set for the life of the frame. Better designs offer some latitude on this, but it's still marginal, so resale value can suffer. 

Lastly, despite this disadvantage, advantages are few, with weight being basically the same for ISP's and the more traditional post design. 

Personally, I wouldn't buy an ISP frame.


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## cxwrench (Nov 9, 2004)

Trek does this on the 5, 6, and 7 series Madones and 5, and 6 series Domane frames. It is a no-cut design though. They offer 4 different seat mast 'caps', 135mm and 175mm height, each w/ either 5mm or 20mm offset. They allow a large range of adjustment w/ this design and nothing ever has to be cut. 
The main benefit is ride quality. It is independent of the post used since the frame is always flexing as intended. With a 'normal' frame the seat tube has to be reinforced to accept a seat post, and the top has to be built up for the clamp. With the Trek design the entire tube can flex more and provide improved ride quality. This is obviously more noticeable on the Domane w/ the Iso Speed decoupler.


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## Rashadabd (Sep 17, 2011)

Look does it on their 695 and Wilier on the Cento1 SR and Ridley on some of their bikes as well.


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## Mapei (Feb 3, 2004)

If you like to buy a new bicycle every few years, and you want to be able to sell the one you got at that time, then it's probably best not to buy a frame with an integrated seat post. Also, if you happen to buy an isp frame and discover you hate it (Damn! It's black; the same color as that guy's bike who always beats me up the hill and then gives me the finger!), you may be plumb out of luck.

On the other hand, if you're buying the bicycle to just enjoy the heck out of for who knows long, there's no reason not to do it. And who knows? Maybe the maker _did _incorporate an isp for a practical reason...


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## Jay Strongbow (May 8, 2010)

Mapei said:


> On the other hand, if you're buying the bicycle to *just enjoy the heck out of for who knows long, there's no reason not to do it.* And who knows? Maybe the maker _did _incorporate an isp for a practical reason...


If looking to keep the bike forever is the case I think there's even more reason to shy away from an ISP (some of them anyway). A lot of the heads/seat clamps on those things are specific to the bike maker so I would be concerned about replacing one that breaks. At best it would need to be ordered and take a while and at worse the company is no longer making them and you're SOL. You'll always be able to go into a bike shop and find a traditional seat post.


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## redondoaveb (Jan 16, 2011)

On the flip side, an ISP frame worked for me. I found a Ridley Noah Pro frame that had the ISP and steerer tube cut and was advertised as used although it had never been built up. Seller sent me BB to top of seatmast measurement and I found that with a seatpost extender from Ridley, the frame fit me perfect. Cost for frame $970.00. I saved about $2,500.00.


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## Roland44 (Mar 21, 2013)

armstrong said:


> I see some carbon bikes advertised as such. Is this a good thing?


As others stated it stands for "integrated seat post". It's definitely a nice feature to have!


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## Kerry Irons (Feb 25, 2002)

Roland44 said:


> As others stated it stands for "integrated seat post". It's definitely a nice feature to have!


Or as others have stated, it's not a nice feature to have.


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## r1lee (Jul 22, 2012)

Cons - could make it difficult to sell. If you have short legs, the ISP is going to be cut low. If you have long legs, this usually isn't an issue for future owners.

Pros - allows for compliance. You'll find a bike with an ISP that much more comfortable.


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## PJ352 (Dec 5, 2007)

r1lee said:


> Pros - allows for compliance. You'll find a bike with an ISP that much more comfortable.


Subjective. Many would argue that experimenting with tire size/ construction/ pressures would do far more to better ride quality.


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## Kerry Irons (Feb 25, 2002)

r1lee said:


> Cons - could make it difficult to sell. If you have short legs, the ISP is going to be cut low. If you have long legs, this usually isn't an issue for future owners.
> 
> Pros - allows for compliance. You'll find a bike with an ISP that much more comfortable.


No reason whatsoever that a bike with an ISP would be "much more comfortable." To the extent that a seat post could make a bike more comfortable that could be done just as easily with a conventional seat post. Tire size and tire pressure will have far more impact on comfort and ride quality than the choice of seat post.


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## paule11 (Jun 11, 2011)

Her is a link to the ISP picture thread

http://forums.roadbikereview.com/bikes-frames-forks/isp-frame-picture-thread-281540.html


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## r1lee (Jul 22, 2012)

Kerry Irons said:


> No reason whatsoever that a bike with an ISP would be "much more comfortable." To the extent that a seat post could make a bike more comfortable that could be done just as easily with a conventional seat post. Tire size and tire pressure will have far more impact on comfort and ride quality than the choice of seat post.


Yes you are right that tire sizes and pressure has more of an impact on comfort. But that wasn't the point I was addressing. The ISP adds compliance and that was what I was addressing.

If you already have your tire size and pressure to your liking, how lower can you go in psi? Additional compliance is what we're talking about here.

The domane is a good example. The 4 series is a normal seat post and it's comfortable. But going up to the 5 and 6 series, trek uses a seat mast which is pretty much an ISP design. There is way more compliance on the ISP design then the non ISP. Much easier for the seat post to flex when there isn't two carbon structure bracing itself.


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## spade2you (May 12, 2009)

Probably something to avoid if you're a beginner. I have a Bianchi frame with an ISP, but only because their next higher model is insanely expensive and the next lower model left a little to be desired.


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## Mapei (Feb 3, 2004)

spade2you said:


> Probably something to avoid if you're a beginner. I have a Bianchi frame with an ISP, but only because their next higher model is insanely expensive and the next lower model left a little to be desired.


A good, practical approach. Putting it another way, don't go nuts over the notion that the bicycle you're considering does or does not have an integrated seat post. There are other more important considerations. Such as Shimma or Campa? Or Sharamm?


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## Kerry Irons (Feb 25, 2002)

r1lee said:


> Yes you are right that tire sizes and pressure has more of an impact on comfort. But that wasn't the point I was addressing. The ISP adds compliance and that was what I was addressing.


And you are confusing yourself if you think there is something inherent in an ISP that makes for a more compliant ride.


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## armstrong (Jul 9, 2013)

Just browsed that picture thread. There was this exchange which gave me a chuckle so I thought I'd repost.

_Special Eyes:_

*Am I supposed to know what ISP means?
*
_James 6B:
_
*Internet Service Provider. All the bikes double as a mobile hotspot.*

LOLz!


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## cxwrench (Nov 9, 2004)

Kerry Irons said:


> And you are confusing yourself if you think there is something inherent in an ISP that makes for a more compliant ride.


That's for sure. There are lots of 'aero' ISP frames out there that most likely have considerably worse ride quality than normal frames.


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