One for the testers?

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Which is more aerodynamic?

The traditional cotton cap
2
20%
Modern UCI legal aero saftey helmet
8
80%
 
Total votes : 10

One for the testers?

Postby -Adam- » Thu Jan 22, 2009 8:21 pm

Which is actually more aerodynamic... opinions welcome, but I'm sure somebody will have some link to an actual scientific test...
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Re: One for the testers?

Postby -Adam- » Thu Jan 22, 2009 8:31 pm

Yeah, we have to wear the saftey helmets in UCI/BC sanctioned events though. I know on the Road to Paris DVD Lance wears a cap in the TT at la Circuit de la Sarthe. Back then they just wore the old style fairing type helmets for serious races.
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Re: One for the testers?

Postby Andrew G » Thu Jan 22, 2009 11:27 pm

I'd go for a helmet as the pointy bit can help smooth the air flow over your back as well as the smoother surface of the helmet offering less wind resistance than a cotton cap. It may sound silly but I find it to be part of the pre-race ritual too, when getting ready at the HQ it helps to try and get in the right frame of mind. Pre-safety pointy hat you used a fairing and a lot of people still do use them (only need a safety version for a UCI rated TT). I bought a safety pointy number as the fairing can be quite hot inside if it's a warm day as there are no air vents, the Giro pointy has a few small ones at the front - still hotter than a normal helmet though.

There's a couple of schools of thought as to which type is better as the longer tapered point is more aerodynamic but on a lot of UK courses a shorter point can work better as you can move the point more when approaching a RAB or a turn and if the point isn't down your back it can be doing more harm than good.

At my speed I don't know how much difference it makes but with a lot of kit I think it's as much the effect it has on your mind. It has been said many times though that a pointy hat is the best bit of aero kit you can buy on a speed/cost ratio.
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Re: One for the testers?

Postby Jon H » Thu Jan 22, 2009 11:51 pm

All depends on how good your position is and how the pointy hat fits in relation to it. The ideal is for the point to be touching your back. If the point is waggling around miles above your back then it's a waste of time and you might as well wear a regular helmet or a cotton cap.
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Re: One for the testers?

Postby Ivor » Fri Jan 23, 2009 5:58 am

Aero helmet cos it makes you feel faster, so you end up going faster. :)
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Re: One for the testers?

Postby mrP(Boonen)VT » Fri Jan 23, 2009 2:44 pm

Not being a fat tester on flat roads, I couldn't possibly comment :wink:
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Re: One for the testers?

Postby -Adam- » Fri Jan 23, 2009 2:55 pm

[quote="mrP(Boonen)VT"]Not being a fat tester on flat roads, I couldn't possibly comment :wink:


By who's say so? :P
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Re: One for the testers?

Postby Marky Mark » Fri Jan 23, 2009 3:07 pm

She has neither....

But how does she steer?

[img]http://bikehugger.com/images/blog/HypeBike.jpg[/img]
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Re: One for the testers?

Postby -Adam- » Fri Jan 23, 2009 3:09 pm

Turn one wheel faster that the other... duh! :wink:
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Re: One for the testers?

Postby -Adam- » Fri Jan 23, 2009 5:28 pm

Another question, with a skinsuit, aero helmet, lycra shoe covers, riding my Cervélo with Zipp 404s, how much slower would I be than if I were riding a full TT bike with disc?
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Re: One for the testers?

Postby Jon H » Fri Jan 23, 2009 5:49 pm

[quote="-Adam-"]Another question, with a skinsuit, aero helmet, lycra shoe covers, riding my Cervélo with Zipp 404s, how much slower would I be than if I were riding a full TT bike with disc?

I refer you to my earlier reply:
[quote="Jon Hemming"]All depends on how good your position is...

Can you fit tri-bars to your Cervelo? If you can, and your bars are fairly low, then you won't be far off from the position you could get on a proper TT bike. The main thing is to make sure you can still put the power down when you're in that position.
The difference between a Zipp 404 and a disk will be marginal.
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Re: One for the testers?

Postby Paul H » Fri Jan 23, 2009 5:54 pm

An aero helmet would make your head wider which would increase resistance perhaps more than the pointy bit reduces it.

What about a swim cap?
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Re: One for the testers?

Postby Keith » Fri Jan 23, 2009 6:03 pm

The airflow will separate off the rear of the swim cap giving a larger wake and hence more drag. That's the Idea of the pointy rear of the helmet - to prevent the air separating abruptly, keeping the wake small, the aiflow smooth, and hence minimising drag.
Last edited by Keith on Fri Jan 23, 2009 6:09 pm, edited 1 time in total.
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Re: One for the testers?

Postby Roy Green » Fri Jan 23, 2009 6:05 pm

[quote="-Adam-"]Another question, with a skinsuit, aero helmet, lycra shoe covers, riding my Cervélo with Zipp 404s, how much slower would I be than if I were riding a full TT bike with disc?


With all these super aids helping you guys today, I'm beginning to think that my rides by comparison in the 1960s would give you a fair run ... :shock: what say, Boss, John L and Keith W?
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Re: One for the testers?

Postby -Adam- » Fri Jan 23, 2009 6:22 pm

[quote="Roy Green"][quote="-Adam-"]Another question, with a skinsuit, aero helmet, lycra shoe covers, riding my Cervélo with Zipp 404s, how much slower would I be than if I were riding a full TT bike with disc?


With all these super aids helping you guys today, I'm beginning to think that my rides by comparison in the 1960s would give you a fair run ... :shock: what say, Boss, John L and Keith W?


Your probably right, the reason I'm asking is for when I have to race over 6km against Rob Hayles and Chris Newton at the Chas Messenger. Or over a similar distance at the Rás Mumhan at Easter...

Jon, I forgot to mention the tri bars, so yeah, them too. And yeah, my bars are pretty low, so I guess my position isn't too different from a normal TT bike set up. I've just heard stories that discs can make a minute difference on a 10?
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