Stiff Bikes = Fast Bikes?

[FlaRider]

Assuming identical geos, weight, wheels, etc., is a "stiffer" bike necessarily faster than more "compliant" bike? I assume there is a slight speed advantage (otherwise why would pros race on "stiff" bikes); however, Dave Kirk's frame flex article (found on his website) got me thinking.

I own a super stiff alu bike (Pinarello Dogma) and a more compliant Ti Crown Jewel. I always reach for the Dogma for races and hammer rides and for the Ti Crown Jewel for training and long rides such as centuries. The Ti CJ is definitely more comfortable than the Dogma but feels noticeably "softer" than the Dogma when a lot of torque is applied to the pedals. Does this mean that the Ti CJ is necessarily slower??

[cpg]

:)

Curt

[Dr. Doofus]

stiff bikes fast




stiff riders not




tied to saddles



usually dead




or embalmed

[TAW]

I've been wrestling with this question. I have a CF bike that is very comfortable, but doesn't seem to have the same zip that a CSI that I sold had. Is it a trade-off between comfort and snap? I've been tempted to buy a stiff bike for racing and keep the Carbon bike for longer rides. Is it possible to have a bike that does both or are they mutually exclusive?

[Fixed]

Bro bikes aren't fast riders are i.m.h.o. :beer:

[mflaherty37]

I use Crisco on the spokes, then the air flows over real easy. I have witnessed gains of easily 2mph.

[Ken Robb]

the Crisco worked for me too but at every rest stop dogs would lick some off and by the last 40 miles I had lost all the "slip-factor" advantage.

The hot set-up is 80-90w hypoid gear oil. It is just as slippery as Crisco and stinks so bad the dogs leave it alone.

[Serotta PETE]

the Crisco worked for me too but at every rest stop dogs would lick some off and by the last 40 miles I had lost all the "slip-factor" advantage.

The hot set-up is 80-90w hypoid gear oil. It is just as slippery as Crisco and stinks so bad the dogs leave it alone.

Sandy is chasing the dogs......thanks for allowing him to catch them (and possibly take your bike also). :no:

[saab2000]

I don't know if my Merckx is not stiff. But it feels less fast (and less stiff) than my Strong. They are outfitted almost identically (same wheels, bars, etc.), but the steel strong feels faster.

That said, I have no idea if it is stiffer. I guess I would need some deflection guages and an alignment table for that test. I don't have them.

Nevertheless, the rider is what makes it fast. Sean Kelly used to crush the world on Vitus aluminum frames, bikes not known for their rigidity.

[Ti Designs]

Red bikes are faster...

[Samster]

Red bikes are faster...

are not.

[saab2000]

Are too. My Strong is red. It is fast. My Grandis was blue though, and it is at least as fast.

[scottcw]

http://www.kirkframeworks.com/Flex.htm

I have found the part about BB/Drivetrain flex especially true. I have owned a couple of bikes that were too stiff and lost energy.

[sirroada]

I own a stiff triple butted aluminum frame and a sweet titanium triple butted frame. Geometries are very similar. I have ridden the aluminum one for 4 years and just got the ti earlier this spring. I instantly noticed the ti was a bit "slower" feeling than the aluminum. The alu had way more SNAP and is hence much more faster feeling. The ti feels like I am going slower...but maybe this is because it is way more refined. Bottom line, I can complete 24.5 miles in and hour and 8 minutes on both bikes. My ego thanks me on the aluminum because of the acceleration response but my A@! thanks me on the ti because of the oh so smooth feel.

[TAW]

The question is not necessarily whether a stiff bike will be any faster, we all know it's the rider, but a bike that has that feel to it when you stomp on it is bound to have an effect, even if it's in the mind. Just as in any sport, no equipment change is going to make you a super star, but there is something to be said for equipment feel and for finding something that inspires you.

[FlaRider]

I completely agree with TAW. I took out my IF Ti Crown Jewel for this morning's hammerfest and the bike felt noticeably "soft" when I jumped out of the saddle from a 30mph pace line to sprint. After the ride, I really wished I had taken out my Dogma, the non plus ultra in stiffness as far as I'm concerned. That said, for long and casual rides, the IF is the bees knees. :)

[Fixed]

Bro when you ride different bikes they always feel diff. on a ride you may be thinking I should have rode this or that.I find you get used to what you ride then it's the rider that makes the diff. not the bike. i.m.h.o. :beer:

[Frustration]

If you get a lot of side flex in the Bottom Bracket, it can feel a bit loose when you put in a big effort. It might not be robbing you of really significant power, but it can sure feel that way.

Other than that, a rough ride sometimes also "feels" faster, so a less compliant bike might also seem faster just rolling...

[FlaRider]

I definitely got the feeling on the ti bike that the BB/chainstays were flexing when I stood up to sprint or bridge a gap. Not exactly confidence-inspiring when you're trying to catch a bunch of guys riding away from you at 30 mph. In other words, these _is_ such a thing as a bike that is too flexy (or even too stiff) for the application at hand. It's not just the rider.

[Fixed]

I definitely got the feeling on the ti bike that the BB/chainstays were flexing when I stood up to sprint or bridge a gap. Not exactly confidence-inspiring when you're trying to catch a bunch of guys riding away from you at 30 mph. In other words, these _is_ such a thing as a bike that is too flexy (or even too stiff) for the application at hand. It's not just the rider.
Bro tell that to one of the greatest sprinters ever Mr. Kelly.Cheers

[scottcw]

I definitely got the feeling on the ti bike that the BB/chainstays were flexing when I stood up to sprint or bridge a gap. Not exactly confidence-inspiring when you're trying to catch a bunch of guys riding away from you at 30 mph. In other words, these _is_ such a thing as a bike that is too flexy (or even too stiff) for the application at hand. It's not just the rider.

But it does have something to do with the rider. A bigger rider will cause a bike to flex that a smaller rider would not. The amount of flex built in to the frame should take in to consideration the size and power of the rider.

I doubt that the fact you were riding a Ti bike had much to do with the flex. I have ridden Ti bikes that are extremely stiff, and I am relatively big.

[FlaRider]

I weigh about 160 lbs but can generate quite a bit of wattage when sprinting. It's true that certain Ti bikes are stiff (my former Legend Ti was quite stiff indeed) but this particular bike (IF Ti CJ) isn't particularly so. I'm actually thinking of racing on steel next season because of its inherent stiffness. Ti is very durable as a material but is characterized by its flexibility. I understand that certain springs used in industrial applications are made out of ti for this very reason.

[flydhest]

I weigh about 160 lbs but can generate quite a bit of wattage when sprinting. It's true that certain Ti bikes are stiff (my former Legend Ti was quite stiff indeed) but this particular bike (IF Ti CJ) isn't particularly so. I'm actually thinking of racing on steel next season because of its inherent stiffness. Ti is very durable as a material but is characterized by its flexibility. I understand that certain springs used in industrial applications are made out of ti for this very reason.

re-read what you just wrote. You can find steel bikes that are more or less stiff as you can find Ti or aluminum bikes that are more or less stiff.

There is no meaningful "inherent stiffness" It is all about the design.

[FlaRider]

Fly, I agree with your point about a builder's ability to design a flexy/stiff frame from any material. That said, I think you would agree that different materials have different properties, one of them being rigidity. Although I did so perhaps inartfully, that was the point I was trying to make with my comment concerning "inherent stiffness." I'm not trying to be flip but I would much rather have a frame made from steel than one made from bamboo, regarless how much "stiffness" the builder is able to design into the bamboo frame.

[flydhest]

FlaRider,

My comment was very much in the context of the Ti/steel discussion going on, but I threw in Alu because it is so much talked about and--interestingly--has been the object of scorn for overly stiff (80s C'dales) and overly whippy (old school Vitus) frames.

Re:bamboo, I have not ridden one of the Calfee bamboo frames, but I can actually imagine it would be very stiff. Strong . . . that could be a different issue. Of course, I am pleading ignorance about the frames. That said, if Calfee is willing to build a bike out of it, I don't know that I would write one off.

[Climb01742]

Just as in any sport, no equipment change is going to make you a super star, but there is something to be said for equipment feel and for finding something that inspires you.

very true. i think each rider has their preferred frame material; and the preference is a mix of physical and emotional things, or maybe stated better...objective and subjective. the subjective matters a lot, and can never be fully explained, or justified, to others...but feels no less real.

[flydhest]

:D i can't resist.

Climb, why frame material, why not just the characteristics of the frame in terms of its stiffness, road feel, and the like?

[Climb01742]

because we have a language to talk about materials. the language needed to discuss ride characterics is, to me anyway, too subjective and lacks precision. for example, i like a little bit of flex in my frames. you might well ask, being who you are, where? how much? in what situations? it's just easier to say i like how carbon rides. ;)

[flydhest]

but, you yourself have said that different carbon bikes ride differently. In the same way, different steel bikes ride differently.

There is not steel ride with a unique definition (despite my (tongue in cheek) and other (completely serious) protestations of steel is real.)

that there may be some commonalities running through the frames of a particular material may be true, but that assertion is far from compelling, with the Cannondale/Vitus example or for anyone who rides a frame 58 or larger, comparing a Big Leg Emma to a Ritchey Logic. The latter is a great race bike, especially for longer rides for people who are medium to small sized. For large frames there is a great deal of flex.

Indeed, you laid down a challenge to those who disparage carbon (luckily, not me) to first ride several different frames made in carbon before concluding they dislike carbon. This sentiment, it seems to me, is at odds with the statement "i like how carbon rides."

btw, when am I buying you that beer I owe you?

[Climb01742]

i'm being lazy. i'm tired and in the end, it ain't really that important. it's only bikes and we only know what we like and dislike, nothing more.