Viewing 22 posts - 1 through 22 (of 22 total)
  • Real world aerodynamics
  • billytinkle
    Free Member

    It’s obvious that pushing through the wind is the biggest chore whilst riding to work, but I had no idea that lowering my stem height could yield a potential 5% decrease in drag.

    I’d often thought that some kind of small fairing in front of the bars could aid my average speeds, but it appears not. I found the following article interesting so thought others may fancy a look…

    http://janheine.wordpress.com/2012/05/02/aerodynamics-of-real-world-bicycles/

    Think I’ll be working on my tuck position!

    5thElefant
    Free Member

    but I had no idea that lowering my stem height could yield a potential 5% decrease in drag.

    Or it could mean you’ll use the drops more and reduce your drag.

    njee20
    Free Member

    Or it could mean you’ll use the drops more and reduce your drag.

    Arms either side of the stem is even better.

    honeybadgerx
    Full Member

    It’s even better if you stare at your stem.

    alanf
    Free Member

    I was going to suggest doing a bit of Chris Froome stem staring for an added reduction, but the honeybadger beat me to it.

    mrmo
    Free Member

    Or it could mean you’ll use the drops more and reduce your drag.

    or not, i seem to remember Garmin coming out with numbers that riding on the tops can be more aero than the drops. It is todo with the angle and position of your arms and hands.

    If you want to go aero, sort the riders position and clothing they are the biggest problem.

    crikey
    Free Member

    But baggy clothes are the uniform; how will people know you’re a mountain biker? 😉

    mrblobby
    Free Member

    Yes, I think it’s more frontal area on the arms if you’re on the drops. If you can get your body in a good aero position on the tops then it’s meant to be better. I guess some people’s chest drops down more when they’re on the drops making them more aero overall. Mine doesn’t move that much and it always feels faster on the hoods.

    gofasterstripes
    Free Member

    [video]http://www.youtube.com/watch?v=NXphEuZF6aU[/video]

    thestabiliser
    Free Member

    Mmm, couldn’t find anything in the text about those tights though – they look like a 40000% increase in drag

    dirtygirlonabike
    Free Member

    I always thought that i was most aero on the drops but actually i’m more aero with hands on the hoods and elbows dropped (and that’s with a -17 stem slammed). Its surprisingly comfy, but if i don’t fancy that, then dropping my elbows when i’m on the drops helps a lot (ie in the wind in a chaingang)

    cookeaa
    Full Member

    The thing I’ve found is that riding with hands on the hoods, forearms basically horizontal is quite comfy for a sustained period, you are at least supporting your upped body weight well on your arms, eventually you will have to shift back to the drops, but it works for a reasonable amount of time, just riding on the drops is still better significantly than sitting up holding the the tops, the most physically comfortable, least tiring / stressful position is unfortunately also the least aerodynamic and does incur noticeable drag I find…

    Holding on either side of the stem (as I’ve seen some do) I really don’t find anything like as good comfort wise, you might have a marginally reduced frontal profile but you don’t support your upper body weight as well, and just end up a bit more fatigued…

    Beyond that you’re probably looking at clip on tri bars if you want more a more aero, sustainable position, which might be OTT for most commuters…

    of course the most “Aero” position is no good if it’s also an increased stress position, there’s a balance to be struck between drag and discomfort… IMO of course, I ain’t no TTer though…

    crikey
    Free Member

    Real world aerodynamics works, a winter ride with chaps wearing baggy waterproof tops that flap in the wind convinced me; I was quicker downhills and when we turned around into the wind to come home, I was quicker uphill too when I would normally have been well behind.

    It was a day so windy that we climbed back on the drops…

    fourbanger
    Free Member

    Get rid of your helmet, easy 5% there.

    billytinkle
    Free Member

    fourbanger Get rid of your helmet, easy 5% there.

    You sir, have obviously not seen my afro.

    fourbanger
    Free Member

    Get a swimming cap over it!

    RustySpanner
    Full Member

    Don’t forget to tape your ears back.

    woollybackpaul
    Free Member

    And gaffer tape your nostrils.

    kcr
    Free Member

    a winter ride with chaps

    Young man,that’s where you’re going wrong

    fourbanger
    Free Member

    Surely the real answer is “recumbent”.

    crikey
    Free Member

    Only if the question is ‘Where would you most like to find a drunken Alex Kingston wearing her best nightie?’.

    fisha
    Free Member

    i think when your on the drops, the straight arm downwards counter the benefit of your slightly lower body profile.

    I agree with the comments that arms bent so the forearm is horizontal when holding the hoods is the best aero position for commuting work and grinding against the wind.

    I do sometimes put a set of tri-bars on the commuter from time to time. I reckon that if your grinding against a strong wind, then the difference between sitting up and holding the hoods and leaned forward with arms on the tri bars equates to between 1 and 2 mph at the same effort. The flip side is that over a period its a bit harder to sustain the tri-bar position.

Viewing 22 posts - 1 through 22 (of 22 total)

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