Dec 23, 2002 5:39 AM
|Contemplating a replacement for a worn (but trusty) Shimano Dura-Ace seatpost, and of course, my thoughts turn to carbon. If it does wonders up front (the fork) it ought to do the trick in back, right? That said, any one have first hand knowledge/feedback on carbon posts from Campy, Easton, or CarbonLORD? Huge amount of setback not necessary - just looking for a relatively standard 27.2 carbon post...
|They look cool but....||Dave Hickey|
Dec 23, 2002 5:57 AM
|IMHO, they really don't help much. I really can't tell the difference in ride quality between carbon and aluminum. I like the look of carbon so I have one on my LOOK. I saw a new Specialized carbon post at my LBS this weekend. I looks very similar the the Campy post. Retail is $59.99.|
|re: Carbon seatposts||divve|
Dec 23, 2002 6:12 AM
|I have an Easton EC70 carbon post on my road bike...can't say I notice any difference between the Thomson that was on there previously. I think most road posts aren't long enough to make a difference in material feel. I basically only got it because it looks cool. Aside from that the Easton is also one of the strongest carbon posts. I didn't have much faith in the one from Campy.|
|Probably not worth it||AFred|
Dec 23, 2002 6:44 AM
|I swapped out my Thompson for a USE Alien. I haven't noticed much of difference in the stiff ride from my Merckx Team SC. It took me so long to get the saddle adjustment right with USE's incredibly clever/stupid clamp, that I've just left it on the bike. It's light and looks nice, but when my saddle slips out of alignment, I'll go back to the best post ever made--Thompson. Spend your bucks elsewhere.|
|Also have a USE Alien Carbon . . .||Look381i|
Dec 23, 2002 7:03 AM
|(25.0) on my Look. It set up easily with my SLR and has stayed solid (I weigh about 170). Nothing really special about it, except that it is at least 2 oz. lighter than most of the competition in that size.
I'll second the Thomson advice for quality and ease of use. Wait until February and buy the new Thomson Masterpiece. It should be released by then (some riding buddies are testing it now). It'll be close to Alien Carbon weight (under 150 grams).
|They DO Make a Difference...||jromack|
Dec 23, 2002 7:14 AM
|but very difficult to quantify. One of these days, I'm going to instrument a bike with accelerometers and a data logger and get some numbers.
In the arena of vibration analysis, there is a thing known as the "Q" factor which relates to how much "buzz" is transmitted through a material.
Things like steel and brass "ring" pretty good, hence their use in musical instruments.
Carbon does have better damping characteristics and a lower "Q" than aluminum, but not by a whole lot, so using a carbon seatpost will make a very minor difference.
There is also the area of reduced natural resonance, but since the post is loading axially and not exposed to much beam deflection, there is minimal improvement by going to carbon.
When I designed vibration fixtures, my material of choice was magnesium. This is a magic material for reducing vibration. Unfortunately, it is not a very durable material, both in fatigue strength and exposure to the environment.
Hence, the best seatpost right now is the Dead Elementi Blackstick with the magnesium head. But for $150, the cost doesn't justify the benefits.
One way to reduce vibration is to fill the hollow part of the seatpost with a vibration dampening material. Specialized has one post like this. Once again it's a trade-off of added weight to benefit gained.
Finally, the biggest absorber of vibration between the road and your butt is the seat itself. It is orders of magnitude higher than what is gained by adding a carbon post.
|and what happened to tires?||cyclopathic|
Dec 23, 2002 7:26 AM
|tires with fine casting (250TPI+), larger volume and lower pressure make more diff then carbon post or seatstays, IMHO|
|and what happened to tires?||jromack|
Dec 23, 2002 3:11 PM
|I was focusing on the seatpost and seat only.
You can definitely play with tire types and air pressure and make a big change in ride quality.
Dec 23, 2002 7:53 AM
|When I swapped out my old AL seatpost for a campy ti seatpost all I got was a slightly brighter and more shiney seatpost. But when I went carbon things got very dark. Black even.
Actually, I really like the range of adjustment I got when I bought my Look ergopost, but I was looking for more setback than you seem to need. Ride quality? Same as before. Same as it ever was.
|re: Carbon seatposts||dickruthlynn|
Dec 23, 2002 9:05 AM
|Specialized sells one called "PAVE", $99, carbon, AND it is a "suspension" type. It has an elastimer(?) built in.|
|I have a Look post||pmf1|
Dec 23, 2002 9:57 AM
|Frankly, I can tell no difference between it, a Dura Ace or an American Classic (both aluminium posts). Carbon posts look cool and the Look does have a lot of fore and aft adjustment. It is a bit on the short side though. Since I don't need lots of adjustment, my conclusion was that the Look post (and any other carbon post) isn't worth it performance wise.
But if you like the looks and have the money to spend, why not? There are worse biking do-dads to blow money on
|All show, no go ... sort of||jtolleson|
Dec 23, 2002 12:09 PM
|but not sorry I bought one. They look great.
I switched from an al American Classic about 3000 miles ago and can honestly say I can tell no difference. Those really having "road buzz" issue in the rear need to evaluate their tires and saddle (and saddle rail) choices long before they worry about their seatpost.