Do stiffer frames really mean faster? Where is the science behind this? For the old salts who've ridden a variety of bikes across decades, can frames be too stiff?
I have seen a heatmap generated of a bicycle in use and there was no significant heat build-up between stiffer and less stiff frames indicating there should not be substantial energy loss associated with more compliance. Indeed, older builders even talked about avoiding making their frames too stiff. In searching for answers, I also came across riders (like Anquetil) using thinner tubing during TT efforts and thicker tubing during races that required sudden accelerations.
What do my fellow WW think about the subject?
Damon Rinard from Cervelo has stated that frames don't tend to show even within the range of error of (two) power meters (3%) if measuring at BB and hub. And so when one frame is say 20% stiffer than another, your gains would be 20% of something smaller than 3%. Unfortunately, he doesn't explicitly state what that less than 3% number is.
Damon gets pretty socratic in this thread: http://forums.cervelo.com/search/Search ... Descending
I rode the new Madone 6 series, and by god it felt like every watt was put directly to forward motion. A sensation I've never really felt. With that said though, the ride quality wasn't nearly as good as my Strong ti frame.
stiffness has more to do with how it feels than how fast it is, stiff bikes are like 300psi in your tubs, feels real quite as your getting bounced all over the place but its really slow. To flexy and it wont go round a corner
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CharlesM wrote:Might as well ask what saddle is most comfortable
What saddle is most comfortable?
What saddle is the best in the world?
There is ofcourse a golden middle ground here, where efficency and comfort is in perfect harmony, but where that is depends on you as a rider.
The biggest actual difference I can come up with is how that feel translates to handling. That's like asking for suspension settings. Some prefer the handling a little looser and some want tight. Throw geometry, wheel choice, tire pressure and all the other variables into the mix and you can't boil a bike down to it's "stiffness" to determine how fast it is.
Like Charles said, which saddle?
It make a lot of sense to me.
BTW, I am skeptical about claims that bikes "feel fast". One thing I like about Jan is he measures things, and his results in brevets (which aren't races, I understand) are impressive. I don't think we have the ability to accurately assess small changes in speed. It's like underpowered sports cars: they go zoom-zoom and feel zippy but they might still get dumped by some guy's overbuilt F350 pickup.
"Laterally stiff but vertically compliant". Kidding.
I can't say I've noticed that sensation as much. I went from riding a mid aughts aluminum race frame (with the obligatory Reynolds Ouzo Pro fork that was de rigeur on such frames) to the steel frame with a brief ride or two on a BMC Road Machine. I can say this: the steel frame is not as stiff as the aluminum frame, but the BMC wasn't either. Both the steel frame and the BMC (which I didn't ride very much) had more "snap" when standing than the aluminum frame which was uncomprimisingly stiff. The old "push the BB with your foot trick" resulted in alum frame > BMC > steel.
Now compare my steel "race" frame (which is built from Columbus Spirit, which is a thin, light tubeset ala Jan Heine's experience in that linked article) to a Surly Pacer (which I've also ridden) and they feel very different. My custom frame fits better, of course, but the front end feels much stiffer. In fact I get more flex from the ENVE fork than from the frame. But there is that sort of snap feeling I can notice that I don't feel on a Surly (which sort of just feels mushy). That's the best I can do to describe it.
Regarding the OP, stiffer is not faster. If anything, I think current trends in the peloton have resulted in less stiff frames than they were churning out ten years ago or so when aluminum was still being raced and carbon was slowly taking over. My experience on a, arguably cheaper alu frame from that era, was that it was incredibly stiff, but it sort of fought against you and on anything less than smooth as hell road, it was uncomfortable. Aluminum still kicks ass in the velodrome for a reason. There the stiffness is unlikely to slow you down as you are really looking at one hard acceleration accompanied by one or two smaller ones (depending on the race) and the course is crazy smooth.
Even if you love carbon (I like good bikes of any frame material), Henry James' FAQ regarding using steel is interesting. Especially his information on ride quality.
Aluminum, as far as I recall, is not technically stiffer than Ti or steel or composite, it usually results in stiffer frames because it is so low in density that one can make big exotic shapes that don't weigh more. My father still has a Raleigh Technicum (bonded aluminum... google it) frame from 86 or so that has fairly small diameter tubes (not even mildly oversized like a keirin frame or a boutique road job) and rode very similar to steel. The materials all have different characteristics regarding other properties (shock absorption, metal fatigue, etc) but I have been told that stiffness isn't really one of them. That more comes from what you make with it (size of tubes, shape, density of the weave, etc).
The fastest bike? The one you beat your old times on. That's one good use for Strava, haha.
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