Handlebar Aerodynamic testing (V20)

[LarryOz]

Yes - I am kind of a testing nut.
But I figure I ride recovery every Mon, Wed, Fri, so why not do different testing and capture data while "recovering". :0
Might learn something that makes me faster!

Today I tested riding with a regular "drop" style handlebar with hands outside resting on the hoods, with hands in on the same handlebars (praying mantis hold), and with a short 10" stub of a handlebar (with the brifters mounted on ends pointed in)
Took a little while to learn to ride this way, but eventually got the hang of it.
I rode a 20K with each of the 3 setups.
Probably a little on the long distance end (20K), as the wind was dead at the beginning, but as I went to the second and third 20K, it was blowing just a little (~5mph).
That is probably why the praying mantis hold did not show any less wattage than the outside "hood" grip, as it has in the past showed a slight gain.
I configured my Garmin so that I could look at all the lap data on a separate screen, that way I could attempt to match the wattage on each run and observe the speed difference.
I did not wear my visor as 100% humidity and it would fog up and get water on it.
Also - brake and D12 wires hanging all over the place, so room for aero gain their too.

Attached is a screenshot of the spreadsheet.
Conclusions:
Because of the wind, the hands out on hood and the praying mantis grip on the regular drop style handlebars showed the same speed (23.4mpg) and power (158watts), although hands-in showed NP 1 watt less for hands in.
Still a very respectable speed for that wattage. Plus average HR = 132'sh!
When I swapped the handlebars to the stub, then with the same power (157watts), my speed increased to 23.8mph. That is a 1.7% gain in speed. It might not seem like a lot, but this would equate to nearly 5 miles in a 12 hour event.
At the end I shifted into the next harder gear and increased my speed to around 25.5 mph. This was still with the stubby handlebars and hands in. I was able to average 25.7 mph on 185 watts. HR avg 151bpm!
My initial goal was to be able to ride the new V20 at 25mph in under 200 watts. That is been accomplished, and I think there is still more aero savings to be had!

My next "handlebar" goal is to build a "dragster" type handlebar for the V so my hands can have a more natural up and down hold.

Gary's friend at work gave me an handlebar rig from an actual top-fuel dragster to try and use. (See photo below). I was hooping to mount this on the end of my top Tube, but it is too deep and brings my hands even closer to my chest.
So, to the right you see the template I have made out of aluminum. I have not bent it yet to the correct shape, as I made the template out of a "not-bendable-friendly" type of aluminum. I am procuring a "5052H32" type of aluminum that has better "bending" qualities.
I'll also have to get some "aero brakes and di2 shifters" to mount inside of it. Then I am good to go for another "test" and comparison.
(Yeah - I could do away totally with any shifting and brakes (think of all the weight savings) and move to a fixie front - that is for later - making a slow progression towards that.

 

[Lief]

Larry, very interesting.
Have you thought (or tried) the superman pose with your hands/arms in the stub style?

Does putting your arms in like this reduce your top-end wattage output because you are less able to handle the pedal-steer?
Does putting your arms out straight (like on bullhorns) get wattage reductions?
I'm about to be testing that myself - I need to take a page out of your book and get a bit scientific but I don't have a second bike to test it on - so I end up "...rather be riding."
Any chance of a front or side pic of how you are sitting/holding the grips on the bike?

 

[LarryOz]

Hopefully Gary will join me for some testing (and photos) tomorrow at the track. That might answer some of your questions.
I am hoping to get into more of a "superman" pose with the dragsters type of handlebar, which will let me extend my hands toward the fork more, since everything will be in between my legs.
But then again, the closer you move you hands and the steering input towards the fork, the more "twitchy" the steering becomes. It will definitely take some retraining of some muscle groups.
It might never be safe for riding in traffic or in a group. Kind of looking into it for track riding and some distance records attempts in the future on a track setup.

I can't move the little stub forward much more or my legs will hit it, so that is how I end up in a more praying mantis position.
Not sure about the top end power. I think if you build up to more power gradually it might help. I know having your hands so close together, the steering is rather "twitchy".
It might just take a bunch of hours riding like this to get used to it though. Time will tell.

 

[JOSEPHWEISSERT]

Have you considered trying a very small custom lightweight carbon fairing just in front of the hands and brifters to smooth the airflow but not block vision and not require a different handlebar? I have been curious about the possibility.

 

[LarryOz]

Have you considered trying a very small custom lightweight carbon fairing

Yes Joe, I have considered it, but I am trying to build the bike so it will be a legal "non-faired" recumbent for UMCA record attempts.
I don't want to get stuck into the "faired" category if you know what I mean. Then I have to compete with everything else that is much faster.
I will construct my "dragster" handlebar to divert as much air over my head as possible. As long as the primary purpose of the "device" is not for airflow it is allow and will not throw you into the faired class.

 

[JOSEPHWEISSERT]

So could you shape the handlebars into fairings? Would that be legal? Just curious.

 

[ratz]

This shouldn't require so much riding to test; this is classic Cda testing.
You can simple use Rolldowns; or Chung AeroLab testing.

For the stated goal of speeds over 21 mph aero will be everything. Golden Chetah isn't that hard to learn; or myself or probably Charles could help you analyze the data. Certainly would be cool to see the results.

Which ever setup you have that is the most aero will be the winner; after that you can "learn" to ride it with power; it just will take practice.

 

[LarryOz]

So could you shape the handlebars into fairings? Would that be legal? Just curious.

Yes, to a point. I have a CF "China made Zipp knock-off" when the cross section of the handlebar looks like an airplane wing.
I think the thing to remember is the design of whatever you have must be mostly to the function of what it is to do.
I made my own "quiver" to go on the back on my headrest to hold my toolset and 2 water bottles.
The UMCA official said that was "barely ok", but it was on the line of being a "splitter " to them as well. That is what I am going off of.

 

[MrSteve]

Maybe this'll help out a little:

With my arms out front, gripping the distal drops under the brake levers,
my arms are both straight out in front of my shoulders and parallel with the ground.
This gives me both speed and power.

With my hands resting on the bars between the friction shifters and the stem, this limits
my power output by removing my upper body's input.
However, it's more aerodynamic, for me, because I wear loose flapping clothing.

This drop-bar is narrow, and is the same width as my shoulders.
The bar end mirror soaks up about a mile per hour, up above 20mph.

I can see, Larry, that your wing-sectioned C-fiber drop-bar is wider than mine!
What that means to me, is your knees have more wobble-room than mine.

Have fun!

-Steve