This weekend I got to ride with a friend Mike Coghlin on two separte days in a variety of wind and temperature conditions. On day 1, he had his LG Rocket on, I was wearing my LG Prologue. Mike is a bit heavier and aero than me, and on one hill (which we did 6 times over the weekend) he was putting ~200m on me in just under 2K. On day 2, with no LG Rocket (I was still wearing the LG Prologue), there was zero difference between us. Granted, we were were going at 65-75 kph so the delta would be larger than 30-40 kph, but it was amazing what a difference the helment made.
If you’ve ever seen the two helmets next to each other, you would know that he is serious. The prologue is not really more aero than any other helmet with minimal venting, it just has a tail out the back. It doesn’t close the head/back gap at all.
I get .5 to .6 mph average on long, flat rides out of the Rocket. Easily as much as I get from aero wheels.
I am dead serious. Same 2 guys, on two different days, only difference was the type of helmet Mike wore and he was 200m further up the road than me on day 1 with the Rocket vs day 2 with a vented helmet.
This is awesome news to me, and quite timely. I took your advice and mounted up those Michelin 650x23 tires on my Zipp/Renn 575 combo for the half relay I’m doing this coming weekend. My goal is to do a 24 mph average. This morning I decided a test ride of the race-day setup was in order. I also have a new skinsuit and wanted to be sure it wasn’t gonna kill me. I wore that, but I didn’t wear my Rocket. I just used my standard, vented helmet. I rode a testy little 45 mile loop in 23.6 mph.
So when I don my trusty Rocket, I should be right on target, eh?
Thanks for the advice on the setup that you gave me yesterday on another thread. As for this thread, half that difference probably had to do with who’d had a good dump before the ride and who didn’t.
I’m afraid you’re probably right that there may have been other factors at play, possibly the referenced well-timed waste discharge. Here is a scientific test, with as many variables removed as practical, of the LG Rocket which shows that it does not do much to benefit the average rider.
I rigged up my race ride on a computrainer, which has a rolling resistance roll down calibration mode to take the tire-road interface out of the equation. The test room also has environmental controls to condition the air within plus or minus 2 degrees Fahrenheit, with laminar flow at the point of discharge. The room is painted a neutral color and is sonically shielded from exterior noise sources so as to have minimal impact on the rider. I also have a variable speed fan that can be repositioned to simulate everything from a direct head wind to a direct tailwind, and any yaw in between. I tested two positions for the helmet. One was a straight on headwind with the fan set to 2. One was a 20 degree quartering headwind with the fan set to 2. I chose to control watts at 200 and see whether the speed would be any greater for the aero helmet versus the regular helmet.
On went the giro atmos (control helmet) and up went the watts to the pre-determined level. Speeds were recorded at both wind positions. Then I used an LG Rocket and ran the same tests. I was very surprised to see no difference in speed. Even repeating the tests with the fan set to 3 at a direct headwind there appeared to be no difference in the performance of the helmets. I did the same thing testing a HED 3 carbon tri-spoke against a box rim (I don’t have a box rim, so I just put a box under the fork). Again, speeds did not change for any of the wind conditions. I concluded that unless you would face conditions on a course that would equate to a fan reading of 4 or more, which is a condition I could not simulate since the knob on my fan only goes to 3, standard aero equipment would be of no use to improve speed.
Tom, thanks for your thoughts. I’d like to stress that this is not hard scientific emperical evidence from a lab or wind tunnel. Just field observations from 2 guys riding in the real world with real conditions on 2 different days on otherwise identical equipment selection on the same hill. People can take it for what the observations were. I fear that this might get out of hand into a PC vs non PC type of discussion.
“I am dead serious. Same 2 guys, on two different days, only difference was the type of helmet Mike wore and he was 200m further up the road than me on day 1 with the Rocket vs day 2 with a vented helmet.”
Do you really think even the same rider (let alone two different riders) perform exactly the same every day? Trying to discern anything from your experience is asinine.
You know, I never really thought of the helmet as a big factor there, but maybe it is. Certainly if the consensus of wind tunnel gurus and experienced athletes and coaches is correct, there should be some noticeable difference when flying downhill at 70kph. However I was heavier with my extra (wet) clothes on Saturday, and I was riding lighter on Sunday while you were still dressed like it was wintertime. Hell, even the extra weight of the Rocket would make me descend a touch faster, so, tough to tell.
One thing I found fun was testing out different aero positions on the descents. The Gats have nice, sweeping curves with a grade that you can ride fast without having to brake even if your bike handling skills are as lame as mine. We were lucky to have a small group of trigeek and roadie setups descending together, and I would switch from aerobars to tuck with hands on hoods to tuck with hands on pads and elbows tucked under all during the same descent and watch my position change with respect to guys in a fixed position. Still couldn’t catch Rick in his “hands on the stem roadie tuck” or that Ian guy in his even more aggressive “tongue on the front tire roadie tuck”, but I was closest when my hands were in the pads, my arms were under me and my head was down in my best “tri geek trying to be a roadie but these stupid aerobars are in my face” tuck.
Jhendric, actually to be more precise, two riders performing differently on 2 different days on differeent equipment. Take from it what you want.
But I have ridden with Mike enough times now on the same hill to have observed 2 things: Both of us in vented helmets = Mike drops me on descents Both of us in aero helmets = Mike drops me even more on descents Mike in vented helmet, me in aero helmet = Mike did not drop me
I’ve long thought the helmet may make as much difference as a disk wheel but never had or saw any empiracle information to substantiate it.
i think we may have an empiracle miracle on our hands.
I think your comment is important. It seems funny people crap on aero helmet wearers but scramble like crackheads to get “the most aero wheels” when the evidence for an advantage is generally the same for either thing. Maybe if aero helmets were carbon fiber and cost 2 grand they would be more accepted.
