Tri Bars = How much time in a 10 mile TT

jaffasnap
jaffasnap Posts: 2
edited April 2009 in Road beginners
I have just started time trialing for the first time this season and have just finished my 4th 10. All have been ridden on my road bike just using the drops with a best time of 27.15. My question is what effect did tri bars have on your times when they were fitted and you had become comfortable using them?

Comments

  • sub55
    sub55 Posts: 1,025
    1%
    constantly reavalueating the situation and altering the perceived parameters accordingly
  • arc123chief
    arc123chief Posts: 28
    1%

    That much?? :lol:

    Seriously, is that all the gains you would get?? is that all the difference they would make added to a TT specific bike also?? or does that just refer to adding aero bars to a road bike??

    I'm interested in this too, as I have a road bike and intend to do some TTs in the near future.....

    Cheers.
  • CiB
    CiB Posts: 6,098
    It must be more than that. I do a 20 mile commute and since fitting the tri-bars my times have dropped. I can't apportion a value to the decrease as there are too many variables - route, apathy, wine consumption prev evening, wind etc - but I know that being down on the bars gives me another 2-3 mph or moving up a couple of cogs to keep the same road speed.
  • Feltup
    Feltup Posts: 1,340
    Set-up Estimated Ave CdA (m^2) Speed (km/h) Power (W)
    Tarmac SL2 | Road Helmet | Drop bars 0.310 40.10 306.6
    Tarmac SL2 | Road Helmet | Clip-on aerobars 0.267 40.27 268.6
    Tarmac SL2 | TT2 Helmet | Clip-on aerobars 0.256 40.38 261.0
    Transition | Road Helmet | Aerobars 0.265 40.17 262.9
    Transition | TT2 Helmet | Aerobars 0.230 40.05 229.0

    That is from an article on this website. It shows that you need almost 40 Watts less power at 40km/h using tribars compared to drops.
    Short hairy legged roadie FCN 4 or 5 in my baggies.

    Felt F55 - 2007
    Specialized Singlecross - 2008
    Marin Rift Zone - 1998
    Peugeot Tourmalet - 1983 - taken more hits than Mohammed Ali
  • jaffasnap
    jaffasnap Posts: 2
    Thanks, Just found that :-

    http://www.bikeradar.com/news/article/h ... aero-19273

    Seems that they are a cost effective way to go a little faster. Now to find some. Any recommendations or pointers as to what to look for when buying tri bars?
  • andy_wrx
    andy_wrx Posts: 3,396
    I'm not too convinced that the majority of tribars will give any gain at all !
    I've seen people on triathlons with clip-on aerobars but in the most gawdawful non-aero positions

    If you get the sort with the elbow pads high above the bars and fit them to a standard road bike with high front end, you'll not be exactly very aero and will probably be far too stretched-out and uncomfortable.

    A proper TT or tri bike has a very short headtube so the front end is low, a steeper seat angle so your hips are further forward and a shorter top tube so the bars are closer to you - basically the rider's body position is the same, but has been rotated forward on the bike (think of a paper silhouette of a rider on the bike, put a pin through the bottom bracket and rotate the rider forward and down : that's what happens on a TT or tri bike, not just slapping some tribars on the front and stretching down on them)

    If you haven't got a TT/tri bike, at least push the saddle forward on the rails and either get some of the 'shorty' tribars like Spinacci's or some which fit under the bars with the elbow pads as low as possible (e.g. Easton Aeroforce MOD) and set them short, rather than getting some which have the elbow pads 3 or 4 inches above the bars and setting them as long as you can.
  • John.T
    John.T Posts: 3,698
    You can get a fairly good aero position on a road bike with clip-ons. I am using Profile T2+ on my standard road position and am in a better position than many of the riders on TT bikes. I can also hold this position for over an hour with no trouble.
    http://martin.photium.com/photo2317621.html
    My Fleet.
  • jaffasnap
    jaffasnap Posts: 2
    Very useful to see those pictures. I can really see how the using the drops gives you a large frontal area compared to tri bars or TT bike. What am I looking for to get a good aero position? Which of the pictures do you consider to show a poor position and why?
  • John.T
    John.T Posts: 3,698
    Not many of them are poor but some would not be comfortable for me. I am getting on a bit. Mine is a compromise to use a standard road bike while still getting comfortable and fairly aero. If I had a TT bike my body would be much the same but rotated forward with lower bars and a more horizontal body. I think my tribars are worth about 1 min for 10 miles but only an educated guess.
    My Fleet.
  • Infamous
    Infamous Posts: 1,130
    Yours doesn't look very aero, your bars are the same height as your saddle and you look like you are sat right up. And your beard negates any aero advantage you got from the tri bars.
  • sub55
    sub55 Posts: 1,025
    good position
    [img][/img]d023_deane-eamonn_1744-193.jpg
    [img][/img]img001.jpg
    constantly reavalueating the situation and altering the perceived parameters accordingly
  • John.T
    John.T Posts: 3,698
    Infamous. I think the OP was asking about fitting tri bars to a road bike not using a pure TT bike. My position is a lot better than when not using them. It is also better than some of the other pics of riders on TT bikes. The arm rests are about 8cm lower than the saddle and while I could lower them a little more at 66 I am getting a bit too stiff to hold a lower position for long and if you can not hold the position then you are worse off. As for the beard it is only stubble really and works like Zip dimples (I wish).
    My Fleet.
  • Alex_Simmons/RST
    Alex_Simmons/RST Posts: 4,161
    John.T wrote:
    Infamous. I think the OP was asking about fitting tri bars to a road bike not using a pure TT bike. My position is a lot better than when not using them. It is also better than some of the other pics of riders on TT bikes. The arm rests are about 8cm lower than the saddle and while I could lower them a little more at 66 I am getting a bit too stiff to hold a lower position for long and if you can not hold the position then you are worse off. As for the beard it is only stubble really and works like Zip dimples (I wish).
    It looks OK to me given what you describe.

    But what about a skinsuit and some gloves that don't have those big flaps at the wrists? Loose jerseys suck a lot of power. As does anything disturbing the air flow like those wrist flaps.

    I did a comparison between "old skool" road bike and "new skool" TT bike here:
    http://alex-cycle.blogspot.com/2009/04/new-skool.html

    not quite "just slap on aero bars" but you'll get the idea. I also isolate the impact of better aero from better pacing and power, and conditions were neutral (same air density and lack of wind).
    RST Sport : Coaching - Training Plans - Powermeters -- My blog -- AeroCoach Australia
  • Infamous
    Infamous Posts: 1,130
    John.T wrote:
    Infamous. I think the OP was asking about fitting tri bars to a road bike not using a pure TT bike. My position is a lot better than when not using them. It is also better than some of the other pics of riders on TT bikes. The arm rests are about 8cm lower than the saddle and while I could lower them a little more at 66 I am getting a bit too stiff to hold a lower position for long and if you can not hold the position then you are worse off. As for the beard it is only stubble really and works like Zip dimples (I wish).
    I think the beard has the same effect as zipp dimples (none.).
  • John.T
    John.T Posts: 3,698
    It was too bloody cold and windy that day and it was really a training race as I was just back from flu. Well half back.
    My Fleet.
  • dnrdnr
    dnrdnr Posts: 27
    Is possible to use a different seat post in order to increase effective seat post angle?
  • kozzo
    kozzo Posts: 182
    From 0% to... difficult to define

    Depends on profile... uphil, downhill, flat...
  • Infamous
    Infamous Posts: 1,130
    dnrdnr wrote:
    Is possible to use a different seat post in order to increase effective seat post angle?
    Yes.

    http://www.parker-international.co.uk/3 ... gn=pid3715

    Designed for Triathletes/TTers that want to use road bikes.

    And you can always just move your seat forward, that would also increase the effective seat post angle.
  • dnrdnr
    dnrdnr Posts: 27
    Thank you - I did of course mean effective seat tube angle.

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