RoadBikeReview.com's Forum Archives - General


Archive Home >> General(1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 )


Carbon Seatpost?(33 posts)

Carbon Seatpost?BhamBike
Jan 26, 2004 5:53 AM
Do carbon seatposts actually soften the ride? Are they a worthy investment or just a status symbol? Can you feel the difference, is or a numb butt just the same on carbon?
re: Carbon Seatpost?Woof the dog
Jan 26, 2004 6:02 AM
no, no, yes, no idea but likely the same

But of course I didn't follow my rule of "don't knock it till you try it." I just think the money that you'll spend on purchasing a carbon seatpost could be spent a lot better. But if you didn't have a problem with money, you wouldn't have posted this question in the first place.

Woof the d.o.g.
re: Carbon Seatpost?innergel
Jan 26, 2004 6:54 AM
1. it did on my aluminum Trek2300
2. worth the money to me
3. I can feel the difference from my old post

BTW - If you are worried about price, the Easton EC70 is only $20-25 more than a Thomson. Not much cash in the long run.
re: Carbon Seatpost?KG 361
Jan 26, 2004 7:01 AM
1-Yes, in my experience.
2-Yes, if you have the cash.
3-Yes, but if your butt is numb, it may be something more than a seatpost that you need.
Postscript-you don't have to spend big $$ to get a decent carbon post. Check out the Weyless posts @ Supergo. I just put one on my KG 461 and it is a really nice post-easier to adjust than the more pricey Look Ergopost that I had on my KG 361.
NO...C-40
Jan 26, 2004 7:19 AM
People who think carbon posts "soften the ride" have vivid imagintions. A carbon post is short and very stiff. It might reduce the transmission of high frequncy vibration by some extremely small anmount, but it won't do a thing for the bigger bumps. A carbon post is a bit lighter and a lot more expensive.

One on the best carbon posts it the ITM Millenium. It's about $90 at www.txcyclesport.com.
Three false statementsBergMann
Jan 26, 2004 5:30 PM
1) "A carbon post is short..."
Carbon posts are made in lengths from 180 to 350mm.
On compact geometry frames and mountain bikes with a 350mm post, this can leave a significant amount of post exposed. 3" exposed post won't make much of a difference, but 6-8" is a whole different ball park.

2) "... and very stiff ..."
it's all about the lay up and the amount of carbon used. It's like with any other material: I rode the very complaint, thin-walled MRC and Synchros Ti posts for years, and then went out and bought a Dean Ti for a new hardtail, only to discover Ti isn't just Ti -- the Dean's walls were twice as thick and it felt like I was riding on a steel girder!
The various generations of Easton carbon posts I've been riding on and off road for the last 5 years have all been every bit as forgiving as my old Syncros posts, and _considerably_ flexier than that Dean.

3) "... it won't do a thing for bigger bumps ..."
Seat tube angles vary, but precisely on larger bumps, shock is not conveyed straight up the seat post to your posterior. Not convinced? Do a little reading up on MTB rear-wheel suspension travel. Also, anyone who has ever hit anything big like a raised manhole cover, speed bump, or baby head while in the saddle knows that you don't just get hit from below: you actually get thrown out of the saddle and then come back down on it -- an impact which is also seldom in line with the post angle. A more resiliant post not only softens the initial impact, it also softens the landing.

For those who ride conventional geometry road frames on well paved roads, I would agree that the comfort of a carbon post is not a significant factor.

To issue a blanket statement that there is no difference whatsoever is simply false, and rather foolish given the range of variation between post manufacturers, bikes, and potential uses.

Given the posts on this board, I can only assume that most American roadies don't do much extended riding on cobbles or venture off road into serious rock gardens.
Anyone who has, knows that the combination of a good resiliant saddle and post combo can make a significant difference in the amount of fatigue you'll experience getting bounced up and down over the course of several hours.

Try it some time. It might just do something for your "imagination."
Feel better now???Dave Hickey
Jan 26, 2004 6:41 PM
The original poster rides a Cannondale R600 so is a carbon post is going to have any effect?-NO. It's not compact and assuming the bike fits, it has very little seatpost exposed.

Given the posts on this board, I can only assume you should do a research before you start blasting everyone on this board.

Sorry for the harsh reply but damn you came across as arrogant as hell.............
more imagination....C-40
Jan 26, 2004 7:00 PM
You've taken every statement out of context or added your own qualifiers to suit your need.

Seatposts are very short relative to the other tubes on a bike frame. My entire C-40 frame (and seatpost) are carbon, but it sure as hell isn't compliant. Since no seatpost, whether it be Al, Ti or carbon will have any significant flex in the axial direction, I take it you're suggesting that the ride can be improved with a post that bends forward or back, or side to side. Personally I don't want a post which exhibits that type movement. Even the longer carbon post on my 5cm sloping TT aluminum frame is short enough that it exhibits no such flexure as far as I can tell.

You also have a viid imagination if you think you can assign "resilience" to a seatpost and not the saddle.

Since my bikes are ROAD bikes, I ride them on the ROAD. That's what we discuss on this forum. The roads that I ride are all relatively smooth asphalt. The roughest surface I ride is gravel sealed asphalt that creates a high frequency vibration. An entire carbon frame does reduce the transmission of this vibration, but little of the improvement can be attributed to the the seatpost. If I were to ride a rough section like cobbles, I'd be smart enough to get my ass off the saddle.
fair enoughBergMann
Jan 27, 2004 1:01 AM
A response to Dave & C-40 in tandem:
Fair enough, the prickly tone of my post was in part reacting to previous threads on the same topic which in my recollection involved a majority of respondents sounding off saying that there is effectively _no_ appreciable comfort difference to be had by switching seat posts.

I've spent enough time abusing my body & equipment both on and off road to know that this isn't true.

Yes I added qualifiers to both my own and C-40s statements because that's what I was doing: qualifying. It's not just that I can feel my seat shell and rails flex under load, I can _see_ the posts on my riding buddies' hardtails flex under load while we ride. I also feel the difference in post flex when I ride the same trail on the same bike with the same saddle after switching posts.
These same forces are at work on a road bike -- just in a diminished capacity contingent upon post length, road surface, frame geometry, rider weight, etc. What is more, you can't ride out of the saddle indefinitely, so there are situations in which you will have to _sit_ over cobbles, cracked pavement, etc.

If the originator of the thread is on a conventional Cannondale frame then what I have to say based on my experience is clearly _less relevant_ than if he were on a bike that were to expose more post. That still does not make it irrelevant to the (largely conceptual) discussion at hand regarding the differences between post makes and materials.

It's one thing to call me on my tone (point taken), but recriminations based on my not having intimated what the threader is riding, or dismissing what I have to say off hand because it is outside the scope of your personal experience is not exactly sticking to the "sporting" high ground either.
Cool. Now that's over. Where did you ride cobbles? nmDave Hickey
Jan 27, 2004 4:29 AM
Where did you ride cobbles?BergMann
Jan 27, 2004 10:31 AM
Germany mostly (where I lived for the better part of the 90s), with some Denmark, Holland, France, Italy and Austria thrown in for good measure.

Most of this stuff was reasonably well maintained (Europeans typically don't mess with speed bumps, they just use a lot of cobbles in inner-city and other areas where they want to keep traffic speeds down), and I rarely ever hit stuff as nasty as what they ride in Paris-Roubaix, but even a quick 20 minute jaunt across town on cobbles on a daily basis is enough to change your attitude about bike comfort & compliance.

One of my regular training rides around the town of Hammeln in Germany (famed as the home of the Pied Piper) featured a good, long stretch of cobbles: it seemed like it lasted for days, but in reality it was probably only 1/3-1/2 of a 3 hour ride that you spent on the rocks.

Truth be told, I can't say I ever spent too much time during that ride worrying about my seat post! Just trying to keep the pace over 20 mph to take the edge off the hits and stay on the dang bike in the wet was enough to keep me occupied.

Try it some time. It will definitely create a soft spot in your heart for what poor old George Hincapie goes through year after year chasing Belgians down muddy farm roads!
If your looking for comfort, switch to 25c tiresDave Hickey
Jan 26, 2004 7:25 AM
Most bikes today come with 23c tires. If you really want a more comfortable ride, switch to 25c tires. The price is about the same as a carbon seatpost and you will notice the difference.
"you're" not "your". note to self.. proof read posts...nmDave Hickey
Jan 26, 2004 7:27 AM
And "proofread" is a compound word.BigFatSal
Jan 26, 2004 12:16 PM
Just to bust you a bit. ;>)
Ditto on the imagination...Elefantino
Jan 26, 2004 7:42 AM
Carbon is stiff. Very stiff. It does not soften the ride, because it would have to give and if it gave it would likely snap.

Vibration, maybe. Softness, no way.

I had a USE Alien and I noticed no difference between that and my Thomson except for the money in my wallet. Believe me, my back of all backs would tell the difference.

But, like anything else, buy a carbon post if it makes you feel good.

FWIW,
Mike
re: Carbon Seatpost?lyleseven
Jan 26, 2004 7:52 AM
If you have a stiff, harsh riding aluminum bike (most aluminum bikes!) the carbon seatpost will make a difference, albeit, slight. Otherwise, they are a waste of money and seize frequently, which can ruin you whole frame....I went back to good quality aluminum, saved money and can't tell the difference.
Let 5 psi out of your tires, send me $100 for the consult. nmSpunout
Jan 26, 2004 8:22 AM
You got that right.divve
Jan 26, 2004 10:35 AM
On my ride yesterday I had my rear tire pumped up too hard by about 10psi. I normally ride about 105 and must have misread the gauge at 115 when I was hurrying. I felt it immediately.
The biggest difference is probably thatdjg
Jan 26, 2004 9:41 AM
carbon seatposts are black. Although some al seatposts are also black. And at least one carbon seatpost is sort of white. But generally, your carbon posts will be darker than alloy or ti posts.

Ride quality: nope--on a standard road frame within standard fit parameters you're dealing with a short rigid post. It shouldn't make a difference and I haven't experienced anything that would make me question that. To be charitable to those who think they feel some sort of difference: depending on your saddle, some clamps might work better or worse than others when it comes to allowing the rails to flex. And that might make a perceptible difference in comfort. My guess is that some folks feel this difference and identify it with the post itself.

Whether they're a worthy investment depends what you want them for and how much you care about the money. Depending on your wallet and your point of view, a cf post may be either a relatively inexpensive or grossly overprice way to dress up a bike and/or trim 75 grams from your ride. I really like the setback I can get with a Look ergopost--it's not a fortune (at least not for me), it looks cool (at least to me), and it helps me achieve a position that I like. So I say that it's worth it. If what you want is some compliance, then move up one size tires and/or reduce your tire pressure by a few lbs. and forget about the post.
They really do make a difference as fantasticallybill
Jan 26, 2004 1:21 PM
black. You can paint, you can anodize, but nothing says black like CF.
Re: feel.
People, let's review. You're talking about a perfectly stiff little pipestem five, maybe six inches long (not you Dan, the seatpost) on the same axis as the seattube. The sensations you are gauging are then being transmitted through horizontal rails of varying materials, with the constant being that they are horizontal and that therefore will dissipate some energy, then, on many saddles, through elastomers, then up to a plastic saddle form (usually) then up through a layer of padding (usually) and THEN up through a layer of leather or faux leather and only THEN to your jiggling butt cheeks. There is no way on God's green earth are you going to be able to sense a difference.
LMAO. great postDave Hickey
Jan 26, 2004 1:29 PM
Unfortunately, I can't get the jiggling butt cheeks visual out of my head..........
Ever ride cobbles?BergMann
Jan 26, 2004 4:49 PM
It ain't about vibrations boy.
A more compliant post, whatever the material, will add some comfort to the equation when the going gets really rough.

If you don't believe this, then you've never ridden for extended periods on cobbles, cyclocross, or an off-road marathon event on a hardtail.
well, now that we've settled that.bill
Jan 26, 2004 7:56 PM
Isn't that the whole issue -- whether a carbon seatpost IS compliant? Can it dampen anything in its 5-8 in of exposed glory? I don't believe that it does. Everything I've read about a carbon fork is that it soaks up whatever vibration it soaks up mostly at the crown, where the steerer comes in, because of the angle. And, with a fork, there is even more suspension effect because of the head tube angle plus the rake. With a seatpost, all the forces go jamming up right straight through the axis of the seattube and the seatpost, with the lion's share of the potential dampening structures coming AFTER the seatpost, making me seriously question whether any differences among rigid materials, and CF is pretty damn rigid, could possibly be felt in the scheme of things.
I fail to see how riding extended periods on the moon has anything to do with making your point. Do I believe that a compliant post could make a difference? Sure. I just don't think that a CF post is compliant, certainly not in the scheme of things. You believe you felt a difference; fine. I just don't see how it's possible.
Bingo: it's all about the ANGLEBergMann
Jan 27, 2004 12:16 AM
Take a good look at your bike. Is that seatpost really running straight up and down? No, it's at a roughly 18 deg. angle from the vertical.
Granted it's less of an angle than your fork blades, but then there's more weight on the back end of your bike, and the diameter of your post is decidedly smaller than your steerer or fork blades.
As another poster intuited above, I'm talking about fore-aft deflection in a post as a comfort factor, and that it happens is a simple observable fact. Go do an extended climb behind someone on a hardtail MTB with a resiliant Ti or carbon post and you will _see_ the post flex under load. Swap that post out for something beefier, and you can see/feel it flex less.

As for the amount of time you spend on the bike, this whole thread is about the _comfort factor_. My point was that if you are only spending very short periods of time on rough terrain, then forget your post, just get out of the saddle. If you're riding for hours at a time, say over babyhead rocks while climbing up a dry streambed at the Dolomiti Superbike Marathon, that's simply not an option.
Under this sort of extended punishment, _believe me_ your body will notice even relatively subtle differences between posts.

As for whether you believe CF can be laid up to be as compliant as Ti or another metal or not, I think the basics of wall thickness and tubing diameters have been covered often enough on this board.

'nuff said.
Actually, what I understand about the crown being the spotbill
Jan 27, 2004 3:59 AM
where the fork gives is that it's the intersection, not necessarily the total angle. I was extrapolating, and maybe just expansively riffing, on the rake as adding to the effect. Re: the seatpost -- I guess that the force of gravity is 16 to 18 degrees oblique from the axis of the seatpost, but that's still almost straight on, and the forces of the bike are still driving right up through your crotch and CF is still stiff as hell. My CF frame is the stiffest bike I have. Granted, it is not identical in design to other bikes or even other CF bikes, but CF is pretty stiff stuff. And there are not a whole lot of design options in the seatpost itself. It's round, and it has to be strong, and it's exposed 5-8 inches maybe. Design in the clamp, yes, in the saddle, lots, but the post itself? I find it very hard to believe that any material or design that works there can make a difference.
I give up! Maybe one day an MTB can convince you!BergMann
Jan 27, 2004 11:16 AM
Yes carbon fiber is a brittle material, but it is not inherently _stiff_ in all applications. That is a function of tube design! Ever use carbon ski poles or golf club shafts? Those tubular sections sure flex a lot!
The same factors that account for differences in the flex of carbon frame tubes (angle of the carbon wrap, butting, and bonding methods) also influence post design.

_Any_ seatpost material, when butted properly, can be used to make a more compliant post. After breaking a couple butted aluminum Ringle posts in the early 90s, I turned my back on AL and never looked back.
Given the proper design, however, you can make a very resiliant post out of either Ti or carbon.

Maybe the best way to put this to rest is to put the post issue in perspective:
I'd rate the most important components in ride comfort as follows:
1) frame
2) fork
3) saddle
4) wheels
5) tires
6) post

Since a good seatpost is around the second or third cheapest item on this list, I _do_ feel it is worth mentioning to someone who is looking for more comfort on a bike they already own.

15 years of torture testing pretty much every post on the market on and off road has made a believer of me.

Since St. Peter won't be sorting us out at the pearly gates on the basis of our seat-post belief systems, however, I propose we just call an ecumenical truce and just lay this one aside as a difference of opinion between fellow believers in the one true sporting faith of cycling!
my list of comfort components:bill
Jan 27, 2004 11:47 AM
1) tire pressure -- 5 lbs can make a surprising difference.
2) tires, good ones, are a joy.
3) fork -- when I went from a Look to a Wound-up, the ride got a lot more alert and significantly stiffer.
4) saddle
5) frame (note that I did not say frame material, just, frame)
6) wheels, I guess, but, to tell you the truth, I haven't noticed any differences among my wheels that I could account for as wheels as opposed to tires.

seatpost is not on my list, sorry, although I will consider it truceworthy to see that it's last on yours.
Now Bill, while I object todjg
Jan 27, 2004 8:10 AM
your needlessly cruel use of the term "little" with respect to my tres french post (most of which is not exposed, thank you), I suspect we mostly agree on all the substantive points here.

I'm sticking to my story about the saddle rails. I think they do introduce (or can introduce) relevant mechanical compliance into the system and it seems to me that some clamps (and/or clamp positions) might work better or worse with some saddles. I cannot tell whether you agree with me or not on that point (although you do say that the rails may serve to dissipate some energy).

To conclude by being even more pedantic than is my custom: you are quite wrong to say that "sensations ... are being transmitted through horizontal rails of varying materials." Sensations do no such thing. Sensations--or the process of sensing--begins, in this case, with sensory tranducers in your butt ("tuches-neurons" or "tns" as we used to say at NIMH). They then proceed not by rail at all, but by little cars, along miniature highways, to the brain, where the real action occurs.
y'know, I at some point I re-read my post and thought, that'sbill
Jan 27, 2004 8:46 AM
not a sensation, that's a vibration or energy or something, but only a pedant ever would mention it.
We have a weiner. So to speak.
Thank you, Daniel.
Not really...dgangi
Jan 26, 2004 10:22 AM
I had a Ritchey Pro aluminum seatpost on my bike and then swapped out to a Woodman Carbo seatpost. The main reason I did this was because the bike shop allowed me to do the parts swap at dealer cost, which was a measly $30.

Anyway, the only real difference I felt between the two seatpost was less "buzziness" with the carbon post. And that's probably because carbon deadens vibrations a little better than aluminum. But that didn't really "soften" the ride per-se.

Honestly, your saddle is probably the best place to start if you want to give your tush a little more comfort. First of all, make sure that the seatpost you currently have allows you to mount the seat in the middle of the rails - this will allow the rails to flex the most, thus giving you a little more suspension. If your seat is all the way back, consider getting a setback post.

Some saddle companies, such as Koobi, make saddles with elastomers at the end of the rails that are supposed to soften the ride. From a pure engineering standpoint, this would make more sense than a carbon seatpost in getting a more compliant ride. I have no experience with these, but the idea does have merit. It's worth checking into.

Thx...Doug
Depends on amount of post exposedBergMann
Jan 26, 2004 2:03 PM
If you ride a compact frame with enough post exposed, you will feel more give in most carbon posts than you would in a stout aluminum post say by Thompson.

There are plenty of folks on this board who are quick to holler "power of suggestion," but as someone who has raced pretty much every post on the market off road, I know for a fact that a quality post (be it Ti or Carbon) with a bit of give built in can make a big difference in long rides over rough terrain.

If you're riding a conventional road frame with less post exposed, then the effect will of course be diminished.
Screw it, for a softer ride buy a carbon fiber bike-ha! (nm)RemmingtonShowdown
Jan 26, 2004 5:52 PM
Carbon posts are like buying a new car...russw19
Jan 27, 2004 2:40 PM
You THINK there is a difference, so you "feel" the difference. But the real reason you bought it was because nobody wants to be the last guy on the block driving around in a 1973 Gremlin.

Marketing is such a wonderful thing. You are now so in tune that you can feel road vibration now. Doesn't anyone see that as a bad thing? If you are actually needing a carbon seatpost for your new super duper fly frame that someone convinced you to spend 2 grand on, shouldn't you be pissed? If the frame is really that bad that you NEED a carbon post to make it smooth, what does that say to the company that sold you a 5 thousand dollar bike? They told you it was better and you bought it. Hook, line, and you are now sinking! What it really told that company is that you will be so crazy as to spend 5 grand for a bike, so you must obviously be that easy to convince that another hundred for a carbon seat post would just be chump change. Well hand over the change, cuz we all are the chumps!

Carbon posts are good looking! First and foremost! That's why we buy them! Not because they ride better... because they look better, they cost more, and they are a status symbol. It's so funny that some people in this thread touched so close to this, but didn't see the truth of the matter. Nobody wants to show up at a group ride with a lame bike. If you are that guy, or are going to lie to the people of this board and say you are that guy, you are only doing it to actually draw attention to yourself via your lame bike. You would be the type to show up at a group ride on a 70's retro bike in wool shorts and wooden-soled shoes just to show how "cool" you really are. Or to show up like that so you can try to ride away from everyone to show that you are really not the chump that you deliberately are trying to look like. (It's like the guys who act like a pr!ck, and then say they are only doing it to "get a rise out of people" instead of just admitting they really are just a pr!ck.)

The reasons to get a carbon post... to have it. Simple. To not be the guy without one. To show off how cool you and your ride are. To lighten your bike. To have the "all-carbon" look, or as much of it as possible. But NOT to dampen vibration. If carbon posts really worked that well, why are suspension designs like the Specialized Roubaix coming out? If carbon posts are as good as someone on here said on cobblestones, then why do some still ride 25mm tires with front suspension, two rolls of super soft tape, and older TurboMatic saddles on race day over those cobbled roads? If carbon were the wonder material, why don't you see guys on all carbon frames riding bare carbon AX Lightness carbon only saddles with their Cinelli RAM bars untaped with super high pressure tubies glued to Campy Hyperions during Paris-Roubaix?

The reason for a carbon post... weight, looks, chi-factor, yes to all those.... but ride quality???? Anyone want to discuss my selling them the Brooklyn Bridge? Maybe the basement of my outhouse?

As I see it... and not trying to offend those who see it differently, just trying to help them really see it.

Russ