Handlebars - Narrow or Aero?

Assuming some sort of magical world where all other elements of your fit somehow remain the same (head height, back position, shoulder height, etc.), I’m curious as to everyones’ thoughts on which gives you a more aero advantage:

  1. Narrower, 38-40cm traditional-shaped handlebars, fully wrapped; or
  2. Aero, 44cm flat-top handlebars, wrapped only just past the hoods, leaving the aerofoil shape unwrapped?

In other words, do you gain more with an aero shape, or with 4-5cm narrower arm/hand position? Not sure if anyone has seen any hard data on this, but I’m also interested anecdotal experience.

well after nearly 4 years of owning my current bike and not replacing the stock 42cm bars, I went both narrower to 38 and aero profile (I got prime doyenne bars), so I’m curious how that’ll change some of my rides in the future. I just put them on yesterday so it’ll be awhile before I get back outdoors to ride. but aero bar shape on its own is allegedly around 5w, with the width I’m sure it all depends on the rider

IMO the narrower handlebar is more aero in that silo situation you describe, as there is probably still less surface aero facing the wind.

In reality with a rider onboard the narrower bar gets more gains, by also narrowing the rider’s profile.

Finally, the question has to be asked “why not both”?!


Obviously a valid point……could be that this inquiry is driven by someone’s (who knows who……) current stock of handlebars, and the need to not further waste/spend money and anger their spouse…………I mean, that’s all purely hypothetical………:roll_eyes:…….allegedly…….


Go narrow and aero


I’m going to assume you are asking which setup is more aero with you actually riding the bike versus just the bike. My gut says the 38 cm bars would have the lowest drag as it would narrow your frontal area the most. But big caveats: if you don’t use a longer stem, then can you get into a position with your arms parallel? Or would you end up in a position that is narrower, but your chest raised more?

You’ll have more flexibility to adjust the position with narrower bars.

I also think it is more aero, the advantage that flat-top bars have over round bars, compared to narrowing the rider’s profile is probably tiny.

The biggest factor isnt is it aero, but how long can you comfortably maintain it.

I like aero profile bars purely out of comfort for resting my hands on them. I’m not going to think for a half a second the shape of my bars or how far they’re taped is having any effect on my performance.


Its nice to have a flat spot to rest your hands

I hate riding round bars now…


Most of the drag on a bike is due to the rider and not the shape of the bike/bars. So going narrower if it suits you is more aerodynamic.

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Why not both? It doesn’t seem like an either or type question. The data I’ve seen thrown around is that an aero road bar saves 3-5 watts. Routing/hiding cables internally saves a watt.

The biggest savings will come from being able to ride with bent arms, forearms level.

I went narrower to 42mm bars. I had bought into the Lemond ‘wider is better’ idea of bar width back in the day so I was riding 44-46mm bars.

In the end bars are marginal gains, positioning is a large gain.

Your body and shoulder position has a far greater impact on aerodynamics than the bars themselves. The narrow bars help your body be more aero, and that’s what really matters. But don’t go to narrow for comfort and handling!

This has already been settled for the most part…

So… tape doesn’t matter, the shape does.
Aero bars = about 4 sizes narrower bars.; note: the narrower the bars, the less that aero profile matters.


  1. Bar width varies by mfg… 3T and Easton 42cm are different sizes. I think there are less sizes than they’ll have you believe exist.
  2. I went slightly narrower and was pretty sore between my shoulder blades for a few weeks. Then it went away.
  3. I don’t like wrapping the flat section, but it does get slippery, so you might want to put something on there for grip.

Anyone have some links for really narrow bars that don’t destroy the bank account? I’m looking for 36cm and narrower. A flat top would be preferred.


Prime Primavera come in a 36cm (C-C) width.

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They look nice!


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Any update on the Prime bars? Looking at switching to them and they seem like a steal for the price

I have them installed but riding inside I don’t have any aero advantage yet lol

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All I’ve got to say is that integrated aero bars, that run cables and hoses through the handlebar and down the head tube, is the devil’s spawn.