How much do aero bars help? I'm not talking tri/TT bars but aero drop bars compared to round drop bars. I know it's not much but I'm curious as to how many watts/seconds they theoretically save.

I saw something recently that showed aero tubing on frames don't help a whole lot but aero wheels make a much bigger difference.

They help a whole bunch for the IAB (Invisable Aero Bar) position where the forearms are rested on the tops. The flatter tops don't hurt as much and are often taped/padded to support this particularly in Merckx type races.

Just riding - I expect very little bit. I'll make it up having seen my kid do testing Merckx with and without them.
~5-10 sec @ 27 mph over 30 min with hands on drops. I'd say position (IAB) is good for 1-2 min.
That again is a made up educated guess number, but they are not as important as wheels, or helmet.

FSA K-Wing bars don't help me at all for speed/watts/seconds.

I bought them for comfort, not speed.


-Tim-

I have brand new K-Wings in the box as junior didn't think the tops were flat enough for that IAB position and thought his arms would hurt.

"Developed in the Specialized wind tunnel, the S-Works Aerofly saves ~17 seconds over a 40km distance versus a traditional shallow bend road bar. This time saving comes from the distinct aero shape, reduced tape on the tops, and full internal cable routing."

I guess it's something. That's almost twice what you get from aero spokes, at about twice the price, so it's ...even?

Not much but if you save a few seconds here, few seconds there, it starts to add up.

A more aero riding position will save you many more seconds and cost a whole lot less than some fancy bars.

A more aero position and more aero bars are not mutually exclusive.

Yes, and OP wants to know "how much [they] help". My answer remains -- they help a lot less than an aero body position. Nobody's stopping you from throwing money at your bike.

My distance for my guess was ~14 miles. 40K is ~24 miles so my guess was about what their Wind Tunnel number was:
But use the IAB - forearm on drops and good for mins. On an optimized bike (that below was not) it is about as good as TT bars, without the handling.

VOS TT Pos.jpg

There's always that guy that shows up.

He probably tells people to take a dump before a ride, too, when they ask how to lighten their bike by a couple hundred grams. "Pooping is free and just as effective!"

Kinda how forums are. This AM someone is asking about train routes and people telling them about the shuttle bus being better. Made me think of this.

To add to the topic and because the question was "how much do aero bars help?" leaving when and where wide open:
On real rough roads, hill climbs aero bars may be worse/not help at all. They limit/change top bar grip.
You will see many pros - with choices use round.

Very tiny %

The bars themselves may not save many watts. But the lower position that you body gets into while using them will save you a lot.

Unless doing the forearms on tops - why would the position be any different?

So, if you're going to be soloing off the front in a road race, or bridging a gap, there's going to be a bit of advantage from facilitating a the IAB position.


If you're not going to ride IAB, the difference is vanishingly small.


If you're just riding around, the difference in speed from just the aerodynamics of the bars is not going to be perceptible.


If you're racing, the already extremely small aero difference is going to be minimized riding in a pack.


The fact that a number of pros choose not to use them indicates there no big advantage.


So, unless you ride IAB, I would get bars that you liked the feel, and look, of, and not worry about their aerodynamic properties.

The IAB position is nice and all, but not the most safe.

Depends where and when you do it. Lots more crashes seen by me with hands on the drops.

^^^^^^^^
This.... next topic.

how much do you think making that little wrapped section thinner and slicker will make the whole unit pass through the air more quickly

So, if you had normal round bars with internal routing, and didn't tape the tops, I bet that drops to less than 5 seconds difference.

7 sec for that rider in that position on a flat solo ride putting out 350W for 30 min.

I only buy flat topped bars. For me, and esp my kid. I like the flatter surface for my hands, he does for his forearms.
They also seem to absorb shock a wee bit better.

We buy them because we like them. For my kid's racing - TT they have mattered, and I expect will again. Many TTs have places separated less than the difference aero vs round bars make.

What about up a hill? On a Chinese bike