carbon seatstays: pluses/minuses?

[Climb01742]

what are the pluses and minuses of carbon STs? i know, in theory, they dampen road vibes to smooth out the back-end. any other pluses? howz about downsides? on a ti frame, would ti STs be lighter? more direct power transfer? or about a wash? thanks.

[bikedadjc]

The advantages of carbon ST stays, are maximizes ride quality, carbon is stronger than steel. It also maximizes ride comfort, as you can ride distances and still feel fresh, with little or no muscle fatigue. With the ST stays on the Legend Ti, and Ottrott St, the pivot makes road hugging and cornering better. Vertical compliance is improved, in the front if you are running the F2 fork, the front and back will have matched vertical compliance. Therefore, improving power transfer, improved handling, and increased comfort. Vertical compliance allows the rear wheel to maintain contact with the road at uniform pressure, optimizing power transfer to the rear wheel. Vertical compliance allows the wheels to track, one behind the other, as the cyclist carves each turn with less effort, and miminizes control loss when cornering over irregular surfaces. Happy riding, Jesse

[davep]

It also maximizes ride comfort, as you can ride distances and still feel fresh, with little or no muscle fatigue.

Wow, if that is true CF stays are better than EPO :rolleyes:

In fact, many people who know much more than I think that carbon stays, fixed, not ST, are more marleting hype than anything, and in many cases are heavier than the aluminum or ti stays. Cannondale is using aluminum in their 6-13 model, the one with carbon main tubes, because the aluminum is lighter and stiffer.

[dbrk]

It is likely that the ST pivot is quite a different experience than other carbon rear seatstay options. I have owned four or five bikes with carbon seatstays, two of which have the carbon chainstays. Only the Carrera Giove does one notice a difference inasmuch as the aluminium spine (seat tube, top tube, head tube) doesn't feel much like aluminum. On the steel Strong and the aluminum Fondriest I'd say that the carbon stays made no difference. Carl Strong agreed that the carbon stays were aesthetic.

I have aesthetic objections too, not insofar as the the stays are ugly but rather that they represent yet another plug-in, virtual-generic part, more of the paintbynumbers. If Dario won't do it there has to be a good reason though none of mine are based on more than impressions. This stuff about vertical compliance, etc., sounds like industry marketing drivel (just like my disdain sounds like grouchy oldschool.)

dbrk

[Matt Barkley]

I keep hearing frequent and knowledgable posters to this forum say they believe carbon stays make no difference. I respect what I believe to be the reasons Dario Pegoretti doesn't use carbon stays or other agreed "plug-ins" on his bikes but..... I have found in more than a few carbon-stayed bikes I have been fortunate enough to ride really favorable qualities. With Aluminum bikes, I believe the carbon really dampened major and minor bumps and vibrations as well as torsional rigidity to the BB/rear-end especially with wish-bone carbon chainstays. These bikes also never skipped on rough pavement or through corners. On thinly gauged steel bikes I found the carbon to add torsional stregth and dampening qualities.

Having restated a little marketing hype in my own words, I do currently ride an all aluminum bike which rides great. Most of that is because I believe the builder is a great builder. But, it ain't as comfy as thse carbon-stayed bikes I am talking 'bout. :)

I had the chance to hammer over some of the most bombed-out craters-everywhere, roads outside of Boston with two other "hammer-dawgs" on Can-of-ales (new ones) and I was on a carbon seat-stayed SC.61.10A mega-tubed frame. I rolled through those bumps while my friends struggled and looked up at me in disbelief. The next day we did a 3 state Mass, Conn, R.I. 136 mile ride and I noticed my friend would pause and "brace" himself for oncoming bumps in the road. His bike had conditioned himself to "brace" readied for the ensueing jolt from the bike. After commenting this observation to him he noticed myself and another rider not doing what he now was doing because of his, "jack-hammer" as he called it frame.

Now I know I didn't mention many names of frames, or riders in this post, and we all can agree to disagree - and much of this ride-quality stuff is fairly subjective... But, I just can't (don't) believe that carbon stays do NOTHING! Yes, they are cheapo plugs-ins which end up costing the consumer more than the origninal harder to work material. We comment on how Carbon bikes feel different than Steel bikes, which in general feel different than ALU. bikes, etc. Now do they (corbon stays) do enough to be justified in application? Can builders do a better job not adding another material to their frame? I think some can, some can't, and some won't. Cool. :beer:

[Climb01742]

in my experience, carbon ST do smooth out rode imperfections, or at least i felt like they did. but i did feel a trade-off under one circumstance: a hard jump out of the saddle, i THOUGHT i felt a bit of a squish (for lack of a better word). i felt this on two frames with pivoting CF ST. at the moment of hard acceleration (or as hard as i can generate ;) ) i thought i could feel the ST "absorb" or squish a bit. stealing just a bit of power. i was/am curious whether others ever felt this effect, and thus trade-off for the other benefits of a CF ST. leading to a larger question: on a ti frame, or a mixed ti/carbon frame, which already absorbs road imperfections well, does the trade-off of CF ST tilt toward an unwanted trade-off? on an alu frame, like matt mentioned, the trade-off is positive and worth it, i think. but on other frames would ti ST, especially under hard acceleration, perform better? you know, squishless? just curious.

[jerk]

climb-o, it ain't about the material buddy it's waht the builder is trying to do with the material....believe you the jerk, pinarello is using carbon to stiffen up the rear end not make it all comfy....remember the paris used to be their bike for the crappy roads....the prince was for when things got fast later in the season.....a whole heck of lot of paris roubaix bikes have no carbon on the assend of'em. telekom's bikes until they started riding whatever the hell is now painted pink, were predominantly princes and operas sans carbon....that being said serotta could have put the stupid pivot on a ti stayed bike and probably achieved more of this suspension stuff they're trying to push....carbon for the majority of amercian builders is pure aesethitic "me too" plug and play crap.....most of the builders truly get this (Independent Fabrications in particular)....listen- the dream b stay was a horribly harsh snappy bike....the regular dream was just soft enough to be livable outside of a tuscan criterium....you want carbon? great, but bear in mind the jerk can count on two hands the people who have any clue what they are doing with it when it comes to complete frames.....when it comes to frames with carbon just on the stays the number shrinks even smaller.

jerk

[Smiley]

Climb , if you felt a squish with the ST stay you must of HATED the DKS system. Again the comprimises are there but I'll take comfort any day over rough roads. Besides I mostly climb seated from my tandem training.

[Climb01742]

smiley, i didn't hate it, but i did notice it. to be honest, neither a ST pivot or DKS squish was/is big by any means. its just there. its a positive for descending. probably positive on the flats. maybe not for ascending.

[jl123]

Boy, the actual (felt) effectivness of suspension on a bicycle is pretty darned complicated to figure out- in the way that we all do today, that is try a bike here and there for a short trial. There are so very many ways suspension gets into the picture: long chainstays, very thin seat/chainstays or DKS type stays or Kirk's Terraplane rounded stays, 35mm tires, Moots type spring, elastomers in the stays and fork, cannondales headshock, the marzoki pave etc etc. Which works, which does not? It would seem that unless each was set up in a fairly exact way and ridden back to back it would be quite hard to tell the differences negative/positive or neutral. I'm sure the testing would be fun. I hope someday some rich dude will sponcer such a thing.

[JackL]

A prominent local (Seattle) builder uses carbon stays because buyers want them, but he says they add weight to his ti frames but add nothing to the ride qualities.

A carbon/ti frame can't be a 'lifetime' frame like an all ti frame, can it? Seems to me that if you like carbon, then the entire frame should be carbon, with no dissimilar materials.

[Bruce]

I've ridden the same model bike with and without carbon seat stays. The carbon seat stays improve the ride, period.

But just avoid the whole issue entirely and get an all carbon bike, lighter, stiffer and more comfortable than obsolite metal based frames.

The future of cycling is carbon. Get on board now.

Bicycles used to be built out of wood. Now they are made out of metal. Carbon is next. Same thing happed in tennis. Show me a tennis pro who uses wood, or even metal.

You will end up with a carbon fork. Why, because carbon is better. You will probably put on a carbon seat post, why? Because carbon is better. Why not just get a carbon bike and be done with it?

[bostondrunk]

I <burp> agree. Just go all carbon, its stiff and light, nothing to become unglued. There are aluminum frames out there that are just as light, but they are more fragile. I would bet that serotta will eventually offer an all carbon bike..

[victoryfactory]

serotta could have put the stupid pivot on a ti stayed bike and probably achieved more of this suspension stuff they're trying to push....carbon for the majority of amercian builders is pure aesethitic "me too" plug and play crap.....
jerk

Jerk is right IMO. I rode a Concours CS with carbon stays for 6 months before
replacing it with a traditional Ti stay model. No comparison. The carbon
version was much stiffer. This stuff about carbon "improving" or "smoothing" the ride is hype, and not neccesarily true. Carbon is such a unique material, and can be made to act in many different ways. Carbon, well executed sure makes a great frame, but it is being used by some manufacturers strictly for sex appeal.
The real aspects of carbon are being realized first by the companies who
have been using it longer and more extensively. The companies who are
jamming a few carbon bits in their frames here and there are just playing
catch-up. Sure, you'll get some effect from that method, but for the
real cutting edge in carbon's use, go with the innovators, not the immitators

VF; names have not been mentioned to protect the guilty....

PS: I fully expect that most people will be riding plastic within a few years. It's coming, don't fight it....

[Climb01742]

VF--so you switched to ti seatstays for comfort? i'm assuming, from your description, the carbon ST were maybe too stiff? with the ti, did you "lose" anything? was acceleration or efficiency of the rear triangle any different between ti and carbon? your experience offers a good side by side comparison. PS: BTW, how does the concours compare to a legend frame? thanks.

[victoryfactory]

Climb;
To answer your first two questions, yes and yes. As for the third question, I'm an old fart, not a racer and truly can't tell the difference in "efficiency" between the two frames.

Finally, as for the difference between legend and concours see my previous post (with pictures and concise, brilliant commentary) here:http://forums.thepaceline.net/showthread.php?t=2650&highlight=victory+Factory

Also, from a previous post re differece between legend and concours:

Zap;
you said: "Serotta needs to weld the seatstay lug to the rear dropout"
I thought the pivot was the point of the Legend ST design.

They already do that (non pivot attachment) on the carbon stay Concours CS
I had one before the Legend and I found it too stiff. Rather than change the
5 degree sloping TT, I (With the help of Kelly at Serotta) had the Legend
built with the Traditional Ti seatstays, longer chainstays slightly longer TT
and trail adjusted for a much more stable, smooth ride.
Before you say "yeah, but that's a legend, I think both models already use the same
tubing for the rear triangle, and i suspect (but don't know for sure) that when
you order (as I did) an OS downtube on either model, you get the same tube! So that leaves those two bikes very similar from a tubing standpoint.
except the TT which is swaged on the Legend.

VF

VF

[Climb01742]

VF--many thanks. :D

[shaq-d]

i don't trust what the pros race in as evidence of a great frame/bike/material/etc., because of obvious commercial reasons.. but i do trust the RAAM riders' choices. almost all of them use carbon (carbon frames, anyway; carbon stays, another matter completely) and beam bikes. the reasons are real good:

http://www.ultracycling.com/equipment/frames.html

sd

[jl123]

Shaq,

Interesting post. I also noted some other interesting artiles on that web-site, like this one: http://www.ultracycling.com/equipment/ultrabike.html

Apparently from what the experts on the Ultracycling site say, dovetails rather closely with what most on this site believe as well. And that is, suspension for bicycles works. It makes the ride smoother, less fatiguing, and allows the rider to go slightly faster into and through most corners/decents.

The only major issue I have with the ultracycling folks is that it seems they have not really sampled the field of recent suspension designs- namely the use of soft-tail moutain bike style (egMoots), rear and possibly front fork suspensions. I can't help but wondering wether soft-tail/fork suspensions-especially if further optimized as Klein is doing (using elastomers with built in negative travel in the chainstays) or using Fox-shocks new anti-bob designs for variable air/oil (in up to 2 inch travel), would provide better handling than the isolated bounce of Softride??

[hooverone]

Who would the innovators of cabon, Calfee, Trek Parlee?

Kestle too but from what I have read their customer service drops them to the bottom of the list.

What I can not get over is I was looking at a Hampsten/Parlee carbon and while it looks great I read the warranty and the crash replacement/fix policy is for the 1st 3 years they are willling too but at a cost of 25% of a new frame that is not a very friendly policy so at years crash and you are sol, I have not seen a crash policy that approaches serottas. So while carbon looks great with the warranty and lack of crash replacement/fix policy......



Jim

[Ken Lehner]

I've ridden the same model bike with and without carbon seat stays. The carbon seat stays improve the ride, period.

But just avoid the whole issue entirely and get an all carbon bike, lighter, stiffer and more comfortable than obsolite metal based frames.

The future of cycling is carbon. Get on board now.

Bicycles used to be built out of wood. Now they are made out of metal. Carbon is next. Same thing happed in tennis. Show me a tennis pro who uses wood, or even metal.

You will end up with a carbon fork. Why, because carbon is better. You will probably put on a carbon seat post, why? Because carbon is better. Why not just get a carbon bike and be done with it?

So will you buy a BB with a carbon fiber spindle? A carbon fiber skewer? A saddle with carbon fiber rails? Carbon isn't "better", at least not all the time.