Correction- he said the Aluminum should be fine. Not carbon

Pull up on the aero bars in order to gain leverage I guess is what he means.

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Find out what it is in life that you don't do well, then don't
do that thing.

Ok thanks!. That seemed simple enough. Wasn't sure of their was something else I was missing!

i pull so hard in TT's that my abs will be sore later.

Would this really be an issue with aluminum bars?

look up Lemond in the 1989 tour final TT. He was pulling so hard on the bars for leverage he nearly broke them off.

no, that part makes no sense. I use aluminum bars and would think if anything
carbon bars would be more prone to fail than al.

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Find out what it is in life that you don't do well, then don't
do that thing.

So do I. I just don't have the mass and leverage from long legs.

It's like I'm doing curls during my threshold intervals just to keep me in the saddle.

jaretj

like others said they are referring to pulling up on the extensions (not the basebar) when in the aerobars. Like others said, this is probably most likely in a TT versus a tri or else a shorter tri, maybe putting down some major power to pass someone or topping out a hill. You're pulling up on the extensions and leveraging against the arm rests to stabilize your body and get a bit more power.

As for if this is okay with carbon or aluminum I have no idea.

First off, I doubt that unless you're a huge guy REALLY yanking on the bars that it would be possible for you to bend or break the extensions.

Second, what is more likely to happen is that the extensions will rotate on the basebar if it's not an integrated bar. You'll pull up, they'll rotate up and you're stuck with a wonky bar the rest of the ride or worse... you crash. I'd actually guess that this would happen MORE on a carbon bar as the friction between carbon parts (your extension mount and the basebar) is usually less than on aluminum and you can also generally tighten the extensions on an aluminum bar quite a bit more without worrying about damaging them. If you're worried about this and want to go all carbon you should DEFINITELY be using a friction paste such as those made by FSA and other companies which you put at any carbon on carbon clamping point (carbon seatpost in carbon frame, carbon bar in carbon stem, extension clamp and carbon base bar in your case) which then increases the friction at that point at any given torque allowing you to get less slippage at a given tightening torque, ie less chance of you rotating them.

All said and done, get the bars you want and if properly tightened and possibly friction pasted, they should not slip. That being said, if you are worried, generally the heavier, cheaper and more overbuilt bars are going to be less prone to any slipping issues. One piece integrated bars should not slip at all, or if they do it's called "breaking" not "slipping" and you're probably going to eat shit when this happens or else at least go "oh shit" when you hear the sound of cracking carbon. I've done this to two of the old HED integrated bars. That being said, they were like 5 years old and I ride my bikes hard so the fact that they broke wasn't anything to do with any short coming on their part.

Good luck!

The guy at your LBS is an idiot. Sure, I understand pulling up on the bars, but breaking them? No way. Bars will all be built to minimum engineering standards, if carbon extensions were too weak I don't think anybody would be buying them. Do an internet search on the number of extensions that break JRA (Just Riding Along), I don't think you'll find too many.

Oh yeah? I pull so hard I have to torque my bars to 15 Nm to prevent me from giving myself a black eye when I'm full on MF-ing beast. That's how hard I pull.

I understand that Kevin Moats doesn't pull hard at all. That's what everyone else is for.

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Find out what it is in life that you don't do well, then don't
do that thing.

Carbon has a greater tensile strength than steel. You couldn't break them even if you wanted to.

Zing!

Aluminum bar will last long with less fatigue and will always remain stiffer than carbon no matter how hard you are pulling on them. In most cases Aluminum bars are lighter than carbon.

I've been doing TTs for years and I'm fairly good at it. I've also messed around with my position ten ways to Sunday. I've noted some setups where I seem to get a bit more leverage on the aerobars than others, but pulling up so hard it makes your abs hurt? Seriously? What say you TT folks? Is this commonplace?

The extensions are a place to lightly rest your hands. Unless you have them hooked up to a system that drives your wheels, then pulling on them is a waste of energy.

I would think that drop bars see a lot more stress than aero-bar extensions as they don't have the arm-rests to support a lot of the weight. Sprinters are probably "pulling up" the drops pretty hard, both aluminum and carbon and you don't see a lot of problems.

ST hubris at its best.

Why do you need to pull hard on the bars at all? I can kind of see yanking on them if you are going up a rolling hill and want to maintain your aero position, but still need to grind your way up the hill. But in most cases, you are trying to relax your upper body to avoid wasting energy.

...if someone could break my carbon bontrager extensions while cycling, they are in the wrong sport and they should be doing 'tough mudders.' thats where the meat-heads hangout.

I was told by a very well-known fitter that I should be doing this, but I never figured it out. I believe this topic has been mentioned previously if anyone feels like doing the search.

---Francis

I'm not sure if your statement is true or not, but what about compressive strength? When you apply a "pulling up" force to the bars, the bottom side of the bars are experiencing tension while the top side is in compression. For example, concrete has a very high compressive strength and a very bad tensile strength... I'm just wondering if carbon is the opposite? Sorry, it's just the engineer in me speaking ;)

Somewhat lower, but still pretty good properties. It would be really tough to break aerobars this way.



How do you tell if you almost broke something? Given the arm strength of the average professional road biker (i.e. just enough to keep their head from hitting the bars), I'm calling bollocks on general principle.