faster than a bare head?
Faster at what?? Probably faster route to being an organ donor with the bare head than wearing the helmet.
Dave
funny guy! you know what i meant…
Why does everyone get a flippin hard on for this helmet?
Grant
cause it looks cool?
but not as cool as a cotton cycling cap turned backwards?
Depends on your head.
man, that was a bad movie…
Hello Gsteinberg and All,
<faster than a bare head?>
http://www.velocitynation.com/article.aspx?ID=1273&CID=54
Not if this test is accurate …
Cheers,
Neal
The Shootout
Now, on to the new numbers. I got my hands on a Giro, Rudy, and Uvex to add to the test. I noticed that the numbers fluctuated quite a bit from day to day, so I tried to do the test as quickly as possible while monitoring room temperature. This test took place over 2 hours on a clear day. Room temperature didn’t change, and I’m hoping humidity and barometric pressure held steady as well. I tucked the helmet straps under, to eliminate another variable. The Garneau was tested with and without a visor. The Uvex was tested only with a visor – the velcro holding it on was a little loose, and I didn’t want to damage a borrowed helmet. All helmets were run alone and with a simulated back. I tilted the styrofoam head up a bit so all the helmets could sit pretty flush to the back, which was held in the same position for all helmets. This raised the drag of the bare head a bit. On to the numbers.
**Helmet Alone**
Bare Head…109
Spiuk Kronos…109
Uvex fp2 …111
Garneau Rocket…111
Garneau Rocket w/ visor…114
Rudy Syton Open…129
Giro Advantage…132
Helmet with back
Kronos…102
fp2…107
Rocket…109
Rocket w/ visor…111
Syton Open…123
Advantage…129
Greetings all, from the info I’ve seen, it depends on whether the head has hair, and how much hair (seriously!), since hair is surprisingly unaerodynamic.
I don’t think that test is very accurate.
probably the most aero headgear ever worn in a TT was the little bubble helmet Boardman wore in some of the Tour Prologues in the 90s.
neal, sincere thanks for the serious reply.
fade, i may have the opportunity to get one of those ‘bubble’ hats. Not CPSC rated, but faster nonetheless.
gideon
great link.
i have to give this guy an A + for creativity. and the helmet article is pretty damn funny. the most amazing thing is that this guy has set up his own “mini wind tunnel” for helmet testing in his NY apartment with the following crazy assortment of parts:
a “22 mph” rented electric fan
a styrofoam head model
a tri spoke aero wheel
a bike workstand
a park wheel truing stand
a bare bike hub acting as a pulley
a few wood drawers
some monofilament
a precision gram scale
some brass weights
who knows what else…
rube goldberg, watch out!
here is his original helmet test with these details :
Hello Gsteinberg and All,
<faster than a bare head?>
http://www.velocitynation.com/...x?ID=1273&CID=54
Not if this test is accurate …
Cheers,
Neal
The Shootout
Now, on to the new numbers. I got my hands on a Giro, Rudy, and Uvex to add to the test. I noticed that the numbers fluctuated quite a bit from day to day, so I tried to do the test as quickly as possible while monitoring room temperature. This test took place over 2 hours on a clear day. Room temperature didn’t change, and I’m hoping humidity and barometric pressure held steady as well. I tucked the helmet straps under, to eliminate another variable. The Garneau was tested with and without a visor. The Uvex was tested only with a visor – the velcro holding it on was a little loose, and I didn’t want to damage a borrowed helmet. All helmets were run alone and with a simulated back. I tilted the styrofoam head up a bit so all the helmets could sit pretty flush to the back, which was held in the same position for all helmets. This raised the drag of the bare head a bit. On to the numbers.
Helmet Alone
Bare Head…109
Spiuk Kronos…109
Uvex fp2 …111
Garneau Rocket…111
Garneau Rocket w/ visor…114
Rudy Syton Open…129
Giro Advantage…132
Helmet with back
Kronos…102
fp2…107
Rocket…109
Rocket w/ visor…111
Syton Open…123
Advantage…129
Yes, the spiuk dominates the simulations, but there was a group that went to MIT that found the Giro to actually work better for some riders. The other thing that makes a big difference - HUGE really - for several of these helmets is to cover the underside of the tail with cardboard. The spiuk has the underside of the tail covered, as does the Uvex. Several of the other helmets become much, much better once you do this.
Rappstar, does the cardboard thing apply to the rocket? I’ve just moved and have a lot of cardboard and tape lying around at the moment so it would be a good time to play 
you haven’t been keeping up, it’s out now
.
I have it on the underside of mine. I haven’t gotten to do a windtunnel test, and I haven’t yet done a before/after test, but in theory, it should prevent eddies forming under the tail if (when) you drop your head. That’s probably why it makes such a big difference on the Giro. The Giro has a relatively short tail that would rarely sit flush with the back of a rider (unless he ran bjorn-like drop). So you would get back pressure under the tail. The cardboard should prevent this. And windtunnel data seems to support this as well - i.e. the spiuk tests very well, the giro improves a lot when you do it, etc.
you haven’t been keeping up, it’s out now
Sorry I guess that waiting a year for the product on backorder has jaded me…yawn
.
Cool, thanks. I get to play with glue and scissors before my next race! I can feel the tail of the rocket against my back most of the time but I do like to look down sometimes. If I think it’s faster it will probably help even if it actually makes no difference
They probably cancelled your backorder after all that…I still haven’t figured out what all the fuss is about, it looks nice enough but I don’t see any reason to think it’s any better than the other good aero helmets out there.
I heard Greg LeMond speak a couple of years ago. At TAMU, the baldhead was considered the fastest over anything hands down. During the TdF TT, the aerobars they concluded gain 8 seconds and the helmet lost them 12 seconds, mostly due to his riding style of looking down. Keau