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  1. #1
    carpe napum
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    Kilo: how much time can I cut w/aero components?

    Question for experienced track riders: How much time can I cut off of my kilo time trial time if I go from a standard track/sprint set up to more aero components? There are lots of factors that come into play, I know, but am looking for a ballpark. Last year I rode a regular track setup, i.e. hands in the drops, spoked wheel, clinchers. Most of the other guys had TT bars, disk wheels, sew-ups, aero helmets. That stuff is faster, but how much faster is what I'm trying to figure out. 1 second in a kilo? More? Less?

    Thanks.

    edit: This is for an outdoor, 333m track. (T-town)
    Last edited by lemurhouse; 05-12-09 at 09:45 AM.

  2. #2
    Lurker for Life yonderboy's Avatar
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    You've probably read the Bike Radar article? In there, they say a full TT setup will save you 9 seconds per km going 40km/h. There are a lot of other variables at play (ie: headwind), but the general idea is you'll need about 22-24% less power to go the same speed in an aero setup versus a non-aero setup.

  3. #3
    Senior Member
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    2-3 seconds faster. It won't get you 9 seconds!

    Kilo is more about strength than say a 40k TT. On a 333 you'll spend most of the first lap out of the saddle accelerating, and here much of the aero stuff is irrelevant. If you can go fast on a sprint bike, you'll kill it when you finally put on the aero stuff, but it's still only gonna be around 2-3 seconds different.

  4. #4
    Lurker for Life yonderboy's Avatar
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    Quote Originally Posted by Baby Puke View Post
    2-3 seconds faster. It won't get you 9 seconds!
    Since everyone is going to nitpick this detail, this is why I qualified myself:

    Quote Originally Posted by yonderboy View Post
    In there, they say a full TT setup will save you 9 seconds per km going 40km/h.
    There are too many other variables at play (start, tire pressure, air density, temperature, food you ate, etc, etc) to determine an actual time savings for a given individual without actually going out and testing it. The Bike Radar article is good in that their methods were sound.

  5. #5
    is actually asian 4zn_balla's Avatar
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    i don't think the type of tire matters that much.

  6. #6
    carpe napum
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    Thanks very much for your responses. The Bike Radar article was just the thing I was looking for. I understand that there are other factors involved and that lab data doesn't translate exactly to real life. 9 seconds per km at 40kmph seems amazingly high to me. But even a few seconds is enough of a difference to see what happens by moving at least to aero bars. I just don't know if I can generate the same power in that position as I can in the drops. Been a long time since I trained with aero bars.

    At my age, on the track my events are actually 500m and 2 kilo, not one kilo. Going more aero clearly a huge difference on the 2 kilo, considerably less on the 500m given the higher proportion of time spent out of the saddle and accelerating to top speed. Still, seems like it might be worth a second or two and that's a huge amount in this short distance.

    Thanks everyone.

  7. #7
    Senior Member
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    I hope I'm not nitpicking Yonderboy, I just don't want the OP going in with unrealistic expectations. I asked this question around my track, they said one second for the bars, one second for the wheels. Simplistic, but my experience bears this out- I went three seconds faster. Of course, your milage may vary.

  8. #8
    abandoning fly:yes/land:no's Avatar
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    there are a lot of problems with the bike radar article that have been discussed ad nauseam in the road cycling/road racing forums. if your position on your track bike is as bad as o'neil's supposed drop position, you are doing it wrong:



    that is pretty terrible looking, and i am guessing that he might have sat up a little to get the aero readings to be more significant. (notice in the outdoor test, the watts required were 307, and indoors, his position looked a lot better, and the watts required dropped to 278!) additionally, when he switches to aero bars on the road bike, notice how much taller the stack is compared to the tt bike. plus, there is the seat tube angle conundrum, with most track positions sitting a little more forward than traditional roadies (opens up the hip angle in the drop position).

    of course, this is not to say that aero position is not important, merely that the bike radar article might have overstated the benefits. further mitigating the conclusion is the fact that the application of those numbers don't take into consideration power decreases due to position change. there will be an adaptation period for any rider making the switch, as well as a learning curve for taking the turns optimally.

    bottom line: get the aero bars, and train on them. they will save you significant time.

  9. #9
    Senior Member CafeRacer's Avatar
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    Too many people use the idea of aero equipment as a crutch for going faster. Maby in a pusuit this works but If your a kilo rider you probably spend a fair amount of time in your areo bars. In the same breath you dont need to go out and buy all sorts of fancy **** to shave a few seconds off your PB time.

    Wheels: If this was your excuse to go out and buy a set of pie plate fancy wheels (Zipp, Easton, Cane Creek) then by all means go buy them but you dont need them. What I would do is get yourself a set of wheels built (or bought) that are stiff, have fast hubs, and tubular rims. Have some half decent high pressure tubulars put on them. There is no shortage of them online. Anytime your doing a speed specific workout use these wheels that way your used to how the faster wheel feels at speed and it may help your speed training. Having fast wheels can save you easily a second when your fairly beginner.

    Areo bars: Guys who train as kilo riders spend half their time on areo bars when they're on the track bike. If your going to do 2 or 3 a year I wouldnt be so worried about it. The trick here tho is getting them set up right. Most people slap them on and assume its instant speed. If you compare side by side a sprinters Kilo bike to say a regular sprint bike the base bar is slightly forward and ever so slightly higher than a drop bar. The key here is your bar has to be in a placement that allows you the hardest and best start possible. I spent close to a months worth of standing start work with just a base bar on untill I got it in the right place. Once that position is acheived you want to set your areo bars up so that your back and head angles dont change when you switch hand positions, all that changes is the closure of your frontal area. The differance areo bars can make varies between riders. If set up properly and you know how to ride them you can save alot of time. In the same breath a year or two ago Jason Quelly who is an olympic champion rode a 1.02 on his drop bar.


    As for the rest of it its a tottal commitment or its not worth it. Meaning if your going to wear booties you might aswel be in a tight fitting skin suit and have a propper areo hat on your mising out. AT the end the day areo kit can save your a couple tenths.

    At this point your best bet for improvment is wheels, and to work on training your limiting factors in a kilo.

  10. #10
    carpe napum
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    Thanks for the info and advice everyone. I've got an old pair of aero bars from back in the day and I'll see how they work out. I've no intention of buying super fancy wheel(s) or helmet etc., but I was curious how much they would save... or what its costing me in time to not go with them.

    Cheers.

  11. #11
    Built only for Kilo.
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    With the same output (watts) You can ride up to 2 or 3 km/h faster in an aeroposition. That means in Kilo appr. 2 seconds - and thats a world!!! Baby Puke says the truth....

  12. #12
    Veteran Racer TejanoTrackie's Avatar
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    Quote Originally Posted by lemurhouse View Post
    At my age, on the track my events are actually 500m and 2 kilo, not one kilo. Going more aero clearly a huge difference on the 2 kilo, considerably less on the 500m given the higher proportion of time spent out of the saddle and accelerating to top speed. Still, seems like it might be worth a second or two and that's a huge amount in this short distance.
    I too am over 50 years old and do the 500m TT instead of the kilo. I race on my sprint bike and I do NOT use aero bars because the time I gain in aerodynamics is offset by the inferior power position and the time it takes to make the transition from the outer bars during the start to the inner aero extensions when I sit down. A 500m is much more of an all-out sprint than the kilo, and you can't afford to back off on the power for even a fraction of a second, which is exactly what happens when you transition on the bars and sit down. It's a totally different situation in the kilo, and I don't know anyone who does the kilo with standard drop bars. Some people use aero bars for the 500m and I'd say its about 50-50 between those who do and those who don't. What I do recommend is a good aero helmet, since it's good for about an extra 2 kph top speed. Wheels are important too. I use a disk in the back and a deep section front with bladed spokes. I use a disk more because it is stiff in transferring power than for its aerodynamics. As far as tires are concerned, I use tubulars simply because they can be inflated to higher pressures than clinchers and are more efficient at transfering power to the track during the start, although they must be glued on properly or else they will be worse. Another consideration is that clincher wheels are generally heavier than tubulars, which hurts you at the start. Once you are up to speed I don't think there is any difference between tubulars and clinchers.

    Oh, and as far as the difference in times between a standard setup with regular wheels, helmet etc. and full racing regalia; when I do standing 500m TTs during practice sessions on my bike with its standard wheels (box rims, 32 round spokes, road tubulars) and standard helmet, I am typically 1 to 1.5 seconds slower than when I use my racing gear in competition. How much of that is the equipment difference and how much is adrenalin I don't know, since I don't train with a power meter.
    Last edited by TejanoTrackie; 07-30-09 at 04:28 PM.

  13. #13
    Senior Member mezza's Avatar
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    Quote Originally Posted by yonderboy View Post
    ... will save you 9 seconds per km going 40km/h.


    Ummmm, if you are going 40km/h then you are going 40km/h. If you go 9 seconds faster at ANY distance you will be faster than 40km/h. By going the same speed you cannot gain 9 seconds. All the aero kit in the world will not make you any faster if you continue to ride at 40km/h - It's just mathematically silly.
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  14. #14
    Built only for Kilo.
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    Quote Originally Posted by mezza View Post


    Ummmm, if you are going 40km/h then you are going 40km/h. If you go 9 seconds faster at ANY distance you will be faster than 40km/h. By going the same speed you cannot gain 9 seconds. All the aero kit in the world will not make you any faster if you continue to ride at 40km/h - It's just mathematically silly.
    You are a funny guy, huh?

    I think He means: With the same output of power You can save with aero-components 9 seconds per kilometre (at speeds over 40 km/h).

  15. #15
    Lurker for Life yonderboy's Avatar
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    Quote Originally Posted by mezza View Post


    Ummmm, if you are going 40km/h then you are going 40km/h. If you go 9 seconds faster at ANY distance you will be faster than 40km/h. By going the same speed you cannot gain 9 seconds. All the aero kit in the world will not make you any faster if you continue to ride at 40km/h - It's just mathematically silly.
    How big is that bucket of nits? Thanks for completely ignoring the power comparison. If you'd like, I can go find the original Road Cycling thread so you can argue with like-minded pedants.

  16. #16
    Senior Member melville's Avatar
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    Quote Originally Posted by mezza View Post


    Ummmm, if you are going 40km/h then you are going 40km/h. If you go 9 seconds faster at ANY distance you will be faster than 40km/h. By going the same speed you cannot gain 9 seconds. All the aero kit in the world will not make you any faster if you continue to ride at 40km/h - It's just mathematically silly.
    What's this 40km/h business, anyway? That's S L O W. 40km/h = Kilo time of 1:30. Slow. Where's the relevant data for 50 and 60km/h? You know, trackie speed.

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