It appears that the industry has discovered that Aero Road bars shave a lot of drag off of a decent road bike. We nit pick the frames to death and yet I haven’t seen a decent comparison of the aero road bars. Is there any Aero difference between a Specialized Aerofly, Zipp Sl-70, Enve SES Aero Road Bar, Cervelo S5 bar, 3T Aerotundo, and the integrated stem/bar options from Canyon/Specialized/Trek? Or are all them significantly better than a round tube and the differences between them is just noise?
I would bet they are all so close to each other that your just splitting hairs.
I just got a pair of FSA K-wing bars to put on my Felt AR. How far do most people wrap the bar tape? I would think just to the curve and leave the flat bar tops unwrapped.
I’ve seen tape on the top of the bars for your hands. It looks weird but it’s functional
Another issue to consider when making a functional or aero comparison: non-aerobar compatible aero drop handlebars will likely have a little bit less aero drag, but they won’t accept any clip on aerobars. However, aerobar compatible aero drop handlebars might be a little thicker in the center, but they will accept aerobars, which of course makes for a much faster overall set up. A shootout between these two types of bars may not be a totally fair one.
Right now I’m looking for any data, even if it isn’t completely ‘fair’. The point you raise is a good one though.
I am awaiting the delivery of some new goodies for my Felt AR. I am changing out the stock 6800 to 6870 and at the same time replacing the bar and stem with the Enve SES Aero road bar and the 3T Integra Team to be able to hide the junction box in it.
One of the deciding factors on the Enve bars vs. the others was that they do in fact have clip-on aero bars available that are designed to clamp on their wide aero cross-section.
I don’t have a link handy, but I think Trek has a white paper or at least some data that their bontrager aero drop bar saves a lot of drag over a standard round handlebar. You can probably find the results on the web.
The other issue is what stem do you test with.
I would personally go with the Sigma X but I know that it will not fit on the Cervelo bar.
If I was to buy a bar right now it would be the Zipp SL-70 with the Sigma X stem as I think that would be the best option.
So what stem do you do the shoot-out with and how do you equalize the results between integrated units and non integrated units. Then you have the ones that can and can’t accept aerobars.
Then you have bars like these.
http://cms.trekbikes.com/pdf/owners_manuals/MY16_Madone_whitepaper.pdf (page 9)
34g drag saved compared to their XXX Aero road bar (which, working backwards, they claim saves about 57g compared to a round bar), though the point you brought up about clip-on compatible clamp width applies here since that is one of the wider clamp width bars.
Cervelo claims 4.4 watts → http://www.cervelo.com/...kes/s-series/s5.html
Trek claims 23 seconds per hour → http://www.bontrager.com/model/11289
Specialized claims 17 seconds per 40km → http://www.specialized.com/...ks-venge-duraace-di2 (The claim isn’t made on the bar’s page, just on the venge’s page)
Zipp claims 7.5 watts of effort at 30mph → http://www.zipp.com/bars/sl-70-aero/
Enve doesn’t claim anything other than it is optimized
All of these claims don’t mention what width bar, or what the control bar is. Also for the watts claims the speed is left out, and the speed is left out of Trek’s claims as well (distance would work too).
Where is the famous Slowtwitch outrage at lack of data? We are getting to the point where these parts are just as important as the frame for finding speed!
edited to add Pink Font!
our tunnel testing is done at 30mph
we did say what the control bar was…but you’re right, we left out the width, sorry: 44cm
/outrage?
The outrage part should be in pink.
Ok…in an attempt to standardize metrics
23 secs / hr @ 30 mph = 23 sec / 30 miles = 23 secs / 48.2803km → 19.055 secs / 40km?
Do you agree or am I taking my unit conversion just a little too literally?
Can I please ask why you used the 44cm bar? I would think that a 42cm would be the most purchased bar there is but if I was going for an aero drop bar, I would rather have a 38cm.
because it’s what we had at the time in both models. it’s not like we do a full production run of every size we’re planning on and *then *decide to hit the tunnel to check our work.
I’ve experimented with 38cm…keep coming back to 40 or 42…that’s just me.
well, you could’ve left it un-pinked for the brands who haven’t/didn’t/won’t answer…
I don’t know the origin of that 23sec (believe it or not, I’m not involved in every tunnel trip or aero project…not sure there’s enough of me to go around for that!), but I suspect it’s based on an average drag savings (without any yaw distribution weighting) through something like a 0-20deg sweep…so yes, probably too literal.
Cervelo claims 4.4 watts
Trek claims 23 seconds per hour
Specialized claims 17 seconds per 40km
Zipp claims 7.5 watts of effort at 30mph
Enve doesn’t claim anything other than it is optimized
- Design bar, wind tunnel test
- Math converting to a metric nobody else yet claims
- ?
- Profit
Wasn’t this pretty much how aero frames were a couple years ago? Just trying to figure it out and keep everyone in the realm of honesty.
I apologize if this is out there somewhere already,
Does bar width make an appreciable difference for aero road bars (or tri base bars)?
I could see how it could impact the shaping as it comes out of the bends.
Related to the above, what is the gain of a rider on Narrower road bars with the rider?
Thanks for your (or any other responders) time.