Carbon Frames, not always best

[richwagmn]

I think there may be a valid point with braking on CARBON surfaces, but for sure the brakes themselves are more than sufficient - i can lock my Record Skeleton (dual-pivot front, single rear) whenever i want. Even in the wet - on alloy rims. (Haven't ridden carbon, so can't comment.)

Braking power isn't a concern. Perhaps modulation and surfaces are the real question.

And there's only so much speed you can carry into any given switchback before the tires give way.

Interesting. I've wondered why Campy when back to single pivot calipers on the rear? I always thought the double pivot brakes were such an improvement. Maybe that power just isn't needed on the rear?

 

[stephens]

What's with the super narrow handle bars on that bike? Seems a little ridiculous. Hipster style meets dh? Good luck with that cockpit at speed. scary.

I think that bike looks awesome. Hipsters have narrow bars because they copy messengers who have narrow bars so they can fit between narrow gaps in cars and whatnot. But for a gravity bike, narrow bars are great because staying narrow is at least as important for being aerodynamic than getting low is. It doesn't look scary to me at all - it's not like you need to turn the bars to turn the bike...just a little counter pressure...

 

[RDV4ROUBAIX]

Why would it not be allowed on the road? Is there some safety issue?

The UCI's argument is that the rotors are dangerous in a pile up of more than just a couple riders, which is a common thing in road racing, CX not so much.

Again, the issue with rim brakes and carbon rims isn't power, it's consistency and modulation. Third issue would be braking power in wet weather, where carbon rims really truly suck.

 

[Vegan Dave]

Interesting. I've wondered why Campy when back to single pivot calipers on the rear? I always thought the double pivot brakes were such an improvement. Maybe that power just isn't needed on the rear?

I think mainly weight savings, but on the rear, it's easy to lock up either way. I never noticed a difference from dual to single.

 

[Vegan Dave]

The UCI's argument is that the rotors are dangerous in a pile up of more than just a couple riders, which is a common thing in road racing, CX not so much.

Again, the issue with rim brakes and carbon rims isn't power, it's consistency and modulation. Third issue would be braking power in wet weather, where carbon rims really truly suck.

I wonder if there'd be less pile-ups if people could brake better, and more predictably...?

Chicken, meet egg...

 

[lostintime]

Follow the money. . . . . follow the money . . . follow the money. Always

I agree that Disc brakes are coming for road bikes. . . like it or not.

That said . . . riders will always crash whatever the equipment is.

 

[bc_hills]

I think that bike looks awesome. Hipsters have narrow bars because they copy messengers who have narrow bars so they can fit between narrow gaps in cars and whatnot. But for a gravity bike, narrow bars are great because staying narrow is at least as important for being aerodynamic than getting low is. It doesn't look scary to me at all - it's not like you need to turn the bars to turn the bike...just a little counter pressure...

Thanks for the quick history lesson on hipsters and for the instant tutorial on how to carve a turn.

What's the point of a "gravity bike" that can't be ridden downhill as aggressively as a traditional road bike? If someone can't see that the cockpit of that bike would provide dangerously twitchy handling, then that person is talking theory not practice.

If you follow the links to check out the videos of that thing going downhill, I think it's pretty clear that the bike has wider handle bars than the one pictured above. That thing is a novelty build and is cool as far as it goes, but that's about it.

 

[RDV4ROUBAIX]

I wonder if there'd be less pile-ups if people could brake better, and more predictably...?

Chicken, meet egg...

Yes, Vegan Dave, but you see that makes complete and utter sense. Unfortunately the UCI technical Committee doesn't have a track record of thinking along those lines.

 

[forty four]

I think that bike looks awesome. Hipsters have narrow bars because they copy messengers who have narrow bars so they can fit between narrow gaps in cars and whatnot. But for a gravity bike, narrow bars are great because staying narrow is at least as important for being aerodynamic than getting low is. It doesn't look scary to me at all - it's not like you need to turn the bars to turn the bike...just a little counter pressure...

hipsters are trend followers trend follows by default are exceptionally stupid in nature. nothing they say about absolutely anything should be listened to they really are the dregs of society and there multiplying
what happened to free thought and individuality sad.

 

[durianrider]

Here is the marketing model:

1. Sponsor riders that could ride well on anything half decent that fitted right.
2. Pretend that the bikes 14% extra stiffness and 136g lighter than the competitors frame is the main reason.
3. Build em so light that are stupidly fragile.
4. Advice people that crashed carbon is very dangerous (it IS!) and should be replaced even if no visible damage is present.
5. Offer new models every year that are lighter and even more fragile.

99% of the time my bike is by far the heaviest in the bunch and 99% Im in the front bunch up the last climb.

Ride strong frames. Eat, live, train and recover so you stop being a weight weenie fatso pollyanna.

 

[blutto]

Certainly this is a troll?

...no...that gentleman is not a troll but merely someone bringing up a potentially important question about modern frame materials behave...

...as an example...modern driver design ( the active parts of a speaker ) has tried with varying amounts of success to use aluminium and carbon fiber as cone materials...while these materials have high stiffness and light weight, which as in bike design, are desirable characteristics, their use is quite problematic...they work well only within a very narrow band of frequencies and outside of that band they go into often violent resonance over-shoots...the driver industry tries to minimize this effect by damping the resonance but the problem with this approach is that it changes the phase response as it lowers the Q ( in simpler terms it messes up the timing response of the system...so that a carbon handle-bar the is highly damped to remove road buzz also affects the time frame of the output of the bar that the rider requires to effectivally control the bike )

...the speaker industry tries to deal with this problem by using high slope cross-overs to limit the driver output so that it never reaches resonance...the problem is that this approach can't be applied to a bike because the inputs that the bike has to respond to are not only broadband but also chaotic...

...so modern bikes, prone to resonance, are generally damped but this may mess with the timing of the inputs that the rider requires to maintain control...in this regard steel is a must better material because it makes a much better spring, which is after-all what a good responsive frame should be...but yes it is heavy and so on and so forth...

Cheers

blutto

 

[Black-Balled]

I blame the gravity.

 

[usedtobefast]

...no...that gentleman is not a troll but merely someone bringing up a potentially important question about modern frame materials behave...

...as an example...modern driver design ( the active parts of a speaker ) has tried with varying amounts of success to use aluminium and carbon fiber as cone materials...while these materials have high stiffness and light weight, which as in bike design, are desirable characteristics, their use is quite problematic...they work well only within a very narrow band of frequencies and outside of that band they go into often violent resonance over-shoots...the driver industry tries to minimize this effect by damping the resonance but the problem with this approach is that it changes the phase response as it lowers the Q ( in simpler terms it messes up the timing response of the system...so that a carbon handle-bar the is highly damped to remove road buzz also affects the time frame of the output of the bar that the rider requires to effectivally control the bike )

...the speaker industry tries to deal with this problem by using high slope cross-overs to limit the driver output so that it never reaches resonance...the problem is that this approach can't be applied to a bike because the inputs that the bike has to respond to are not only broadband but also chaotic...

...so modern bikes, prone to resonance, are generally damped but this may mess with the timing of the inputs that the rider requires to maintain control...in this regard steel is a must better material because it makes a much better spring, which is after-all what a good responsive frame should be...but yes it is heavy and so on and so forth...

Cheers

blutto

that makes total sense. if you can't get the road vibration input from the bike to your points of contact, then your reflexes will be off or delayed. and next thing you know, you are on the ground.

 

[blutto]

that makes total sense. if you can't get the road vibration input from the bike to your points of contact, then your reflexes will be off or delayed. and next thing you know, you are on the ground.

...while my input was a bit of speculation based on the use of carbon fibre in a very different application it is an application which can be easily and properly tested in a one cause analysis way ( driver assembly makers often use the same assemblies to house cones made of paper, polypro, aluminium, magnesium, kevlar, carbon and various hybrid honeycomb materials ) and ASTM tests are available for each product, there is another example, though anecdotal, that I would like to offer...

...a while ago one of the major cycling mags did a bike test by three reviewers of three bikes that used various materials to form the frame....the upshot of this review was the steel bike, a Merckx, cornered much much better than the other two more modern frames....what was especially interesting was that the two younger reviewers, who were inured in the light and stiff mode of frame design, and who had never even seriously ridden a steel frame, were not initially capable of taking advantage of the cornering capabilities of the steel bike...they had in fact internalized the limits of the new normal that is part and parcel of handling inherent in modern bike design...

...now throw in carbon rims which have very iffy brake reformance and rider positions that have large differences between bar and saddle height (and which accentuates weight transfer upon braking thereby putting too little weight down on the rear wheel ) and you have a situation where control could easily be lose...like driving a late 60's big block Mustang at speed ( really cool in a straight line but terrifying on braking and in corners...the brakes were awful and the weight balance front to back was something like 65/35 )

...a case perhaps where what looked good on paper(in both the design and advertising sense) got hit right between the eyes by reality which is unfortunately chaotic and hence unpredictable...

Cheers

blutto

 

[Marva32]

Timeline too tight? It can't happen soon enough! Yeah maybe for the UCI, their concept of time still dates back to when rocks were soft, but they finally pulled their heads out of the sand and legalized for CX use. It's an inevitability that rim brakes will be phased out of road. 5 years or less before they hit the road in force. Modulation and consistency are the the biggest problems that we all know plagues rim brakes on carbon rims, both of these issues are resolved with disk brakes easily.

I thought you wrote heads, I was going to agree with that

 

[Marva32]

I wonder if there'd be less pile-ups if people could brake better, and more predictably...?

Chicken, meet egg...

If not fewer pile-ups, I don't think you would have seen as many riders going straight off the roads going down the mountains.

 

[Hawkwood]

.
...now throw in carbon rims which have very iffy brake reformance and rider positions that have large differences between bar and saddle height (and which accentuates weight transfer upon braking thereby putting too little weight down on the rear wheel ) and you have a situation where control could easily be lose...like driving a late 60's big block Mustang at speed ( really cool in a straight line but terrifying on braking and in corners...the brakes were awful and the weight balance front to back was something like 65/35 )

...a case perhaps where what looked good on paper(in both the design and advertising sense) got hit right between the eyes by reality which is unfortunately chaotic and hence unpredictable...

Cheers

blutto

Some very interesting points. When I started racing the recommendation was that the saddle/bar drop should be 25-50 mms, at the time with this sort of set-up pros typically had bent arms down on the drops. Now with some set-ups with 100-150 mms of drop pros ride on the drops with straight arms.
I ride a size XL Specialized Secteur frame, the same geometry as the Roubaix. In some circles this is slated for being too upright with too long a headtube, however with all of the spacers in place my saddle/bar drop is 70mms, and I can get it to 105 mms by losing them, and to about 120 mms by using a different stem. I can't get a proper position on most modern frames due to the geometry. We seem to have lost sight of proper efficient positions in a bid to follow fashion. As you state changing the weight distribution is going to affect the braking characteristics.

 

[richwagmn]

Some very interesting points. When I started racing the recommendation was that the saddle/bar drop should be 25-50 mms, at the time with this sort of set-up pros typically had bent arms down on the drops. Now with some set-ups with 100-150 mms of drop pros ride on the drops with straight arms.
I ride a size XL Specialized Secteur frame, the same geometry as the Roubaix. In some circles this is slated for being too upright with too long a headtube, however with all of the spacers in place my saddle/bar drop is 70mms, and I can get it to 105 mms by losing them, and to about 120 mms by using a different stem. I can't get a proper position on most modern frames due to the geometry. We seem to have lost sight of proper efficient positions in a bid to follow fashion. As you state changing the weight distribution is going to affect the braking characteristics.

I don't understand pro frame sizing either. Most of these guys are riding frames with a huge amount of seat post showing with the stem slammed against the headset.

And yes, many of these guys have almost fully extended arms on the drops.

IDK, maybe it's the most efficient position to be in. I just know I couldn't ride anything close to that position.

 

[stephens]

The modern pro riding position has nothing to do with fashion! It's science. All this stuff is tested these days.

 

[Hawkwood]

The modern pro riding position has nothing to do with fashion! It's science. All this stuff is tested these days.

Not sure this is necessarily true for road positions, plus even for time-trial set-ups there are some real shockers out there. It seems to me that riding on the hoods is the new riding on the drops. I believe that one Tour rider was even sprinting on the hoods the other day! Call me old-fashioned, but I don't think I've ever seen any rider with a better position than Roger de Vlaeminck, and he was riding before the invention of science, compact frames, slammed stems etc. I was out cycling with a French club last week, their guys were mainly ex-racing men, several of them had majorly up-turned stems in order to get the right position.

 

[stephens]

What does "right" mean to you? Most comfortable? Looks best? That's what non-pros may be concerned about. The pros just want the minimum comfort that allows them to survive the day while putting out the most watts.

Even recreational cyclists these days are using "science" to adjust their position. When I did a bike fitting, I could see the changes in power output based on the changes in position. I wasn't in a wind-tunnel of course, but in general, lower and narrower is better there, so just keep lowering the bars until it restricts breathing too much or costs power for some other reason or is too uncomfortable to be sustained for the length of the ride.

 

[blutto]

The modern pro riding position has nothing to do with fashion! It's science. All this stuff is tested these days.

....been at this game for almost 40 years and have seen positions come and go...and in most cases each position was sold, errr, validated by a test...

...you gotta remember that tests should have at least a nodding acquaintance with some sort of scientific basis...the problem with that, is that science has this weird consistent characteristic when looked at in the long view ( the historical sense), it has always been proved wrong....

...for an example just take a quick look at the evolution of ideas pertaining to cycling in the realm of triathletonics....there is a lot of well tested debris in that realm which on sober second thought is laughing out loud funny...sort of like a division of the Ministry of Funny Walks...

Cheers

blutto

 

[Hawkwood]

What does "right" mean to you? Most comfortable? Looks best? That's what non-pros may be concerned about. The pros just want the minimum comfort that allows them to survive the day while putting out the most watts.

Even recreational cyclists these days are using "science" to adjust their position. When I did a bike fitting, I could see the changes in power output based on the changes in position. I wasn't in a wind-tunnel of course, but in general, lower and narrower is better there, so just keep lowering the bars until it restricts breathing too much or costs power for some other reason or is too uncomfortable to be sustained for the length of the ride.

`Right' for me means being able to ride others off my back wheel into a headwind, or up a climb. I've had a bike fitting (wired up to a computer etc) and it suggested a saddle/bar drop of 70-90 mms, I'm riding with 70 at the moment which feels good and appears to be effective. However getting a drop of 70 when most modern frames in my size (61 cm or XL) have headtubes of 190 mm is virtually impossible, I've tried. Look at the Roger de Vlaeminck's position, I don't see many pros today getting as low.

 

[LugHugger]

What does "right" mean to you? Most comfortable? Looks best? That's what non-pros may be concerned about. The pros just want the minimum comfort that allows them to survive the day while putting out the most watts.

Even recreational cyclists these days are using "science" to adjust their position. When I did a bike fitting, I could see the changes in power output based on the changes in position. I wasn't in a wind-tunnel of course, but in general, lower and narrower is better there, so just keep lowering the bars until it restricts breathing too much or costs power for some other reason or is too uncomfortable to be sustained for the length of the ride.

Measuring power output on a static trainer is of limited relevance to real world riding. It's just another way of selling to you based on half truths with limited applicability. That's why riders change their position and frames for races such as Paris Roubaix and for high mountain stages. A bike fit may be a useful indicator but should only be considered as guidance. The majority of bike fits are performed after a ten minute warm up in a zero incline model ie of limited relevance to real riding conditions. Bike fit should always be adjusted for physiology and terrain. To try and apply one fit to all terrain and riders is simply ignorant.

 

[cawright1375]

I had an experience two weeks ago that will forever make me a fan of carbon fiber frames.

I was descening a hill, going about 30 mph, when a car pulled out of a side road directly blocking me. I had the right of way and no way to stop. I went right into the back quarter panel and was flung over the trunk, landed so as to have my head bounce and came to rest on my hands and knees. By all accounts I ought to have just gotten out of the hospital, but I only spent an afternoon in the ER getting patched up.

My bike a 2006 Trek Madone 5.2 OCLV was destroyed. The steerer tube blew out of the headtube and the deep rim of my carbon wheels blew apart as wheel. The bar (also carbon) was obvioulsy cracked in multiple places under the bar tape. I'm convinced the carbon fiber is what save my skin.

I'm in the camp that the number of crashes this year has more to do with nerves, fatique and poor bike handling than anything else. There did seem to be a higher than normal amount, but I don't think the frame has anything to do with that, unless there was a material failure that would then cause a rider to go down, taking others with them.

As for postion, etc., I'm sure that like someone else pointed out this changes all the time and for each rider it will be different. I personally think the bikes look cooler with the bar & stem "slammed" down. Do I have my bike set up that way? No, but I still liked the set-up I had, because it fit and worked for me.

As for the OP, it does seem, while an interesting discussion has arisen, that they were trolling to some extent. I might have missed it, but it appears they have not responded since the post.