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Which of these 7 Triathlon bikes would you buy ??
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12-03-2009 4:59pm#1
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Thats true but if I picked 4 bikes that were recommended by the experts(yeHome:Ballyhoura wrote: »Prices on ebay bidding can double or more in the last hour so you can't be sure exactly any of them will sell for!
, I could research the new prices and hopefully pick a bargain.
I am new to triathlon, played hurling for years but had a torrid time last year with injury's so trying triathlon now.0 -
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scottreynolds wrote: »I think for around €1200 you could get yourself a new bike say from Wiggle that would be every bit as good as most of those bikes and more importantly you would get the correct size. There's honestly no point buying a wrong fit bike full stop -- I imagine however a TT bike that doesn't fit is like wearing underwear three sizes to tight.
I say my budget is around €800 - €900. I was thinking on getting a used bike as you would be getting more quality at a better price.
Is there such a difference in frames from 56 - 60 ?
Im 6 foot, it seems most 6 foot guys are riding on a 56 - 58 frame but thats just from my observation over the last few days and not from any experience.
I'll go and get a fitting, it would be a good place to start 0 -
Emmmm bullsh!t.
Very very few people in a triathlon will go under 60 minutes for 25 miles. If the OP can stay in a aero position for the 25 miles they will get a benefit - both on the bike and on the run.
There is plenty of evidence that improved position and aerodynamics can both improve speed during TT's and in 10k runs following cycling in a triathlon.
Most of it relates to elite level and optimal benifit occurs at averages of 50Kpm speeed. There is no published evidence that a time trial bike will make you go any faster at speeds below 40kph (a 1hour 25 mile tt). Seat positioning, bike angles, aero bars and positioning to reduce frontal drag yes but no published evidence at lower speeds for TT style bikes that I am aware of.
You can stay in an aero position without using a TT style bike and biodynamically if you have not the core strengt or conditioning to use it (TT style bike) your running may be adversely affected.
Bottom line is the pubished evidence is almost always on elite triathletes and cyclists that suggests positioning and aoerodynamics improve stimes and running speeds after cycle sections. This does not mean a TT style bike is the best option by any means.
These studies apply to elite levels and seem to peak at cycle speeds of 50KPH. A novice triathlete or one who cannot beat the hour is better served with a road bike with clip on bars and coaching rather than trying to mimic extreme positions.
You may feel this is "bull****" but would love to see what evidence you base this on
You yourself state that very few people go under 60 mins for 25 miles , so what part of my reasoning is it that you have an issue with.0 -
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There is plenty of evidence that improved position and aerodynamics can both improve speed during TT's and in 10k runs following cycling in a triathlon.
Most of it relates to elite level and optimal benifit occurs at averages of 50Kpm speeed. There is no published evidence that a time trial bike will make you go any faster at speeds below 40kph (a 1hour 25 mile tt). Seat positioning, bike angles, aero bars and positioning to reduce frontal drag yes but no published evidence at lower speeds for TT style bikes that I am aware of.
You can stay in an aero position without using a TT style bike and biodynamically if you have not the core strengt or conditioning to use it (TT style bike) your running may be adversely affected.
Bottom line is the pubished evidence is almost always on elite triathletes and cyclists that suggests positioning and aoerodynamics improve stimes and running speeds after cycle sections. This does not mean a TT style bike is the best option by any means.
These studies apply to elite levels and seem to peak at cycle speeds of 50KPH. A novice triathlete or one who cannot beat the hour is better served with a road bike with clip on bars and coaching rather than trying to mimic extreme positions.
You may feel this is "bull****" but would love to see what evidence you base this on
You yourself state that very few people go under 60 mins for 25 miles , so what part of my reasoning is it that you have an issue with.
Lets look at a rider at 28.8 kph (or 8m/s)
Lets put that rider on a surface with a CRR of 0.002 and a slope of 0.01
Lets assume a reasonable TT position - say an effective frontal area of 0.4m2
The power required to ride at 28.8kph is 133.4 watts
Now lets assume a road position - an effective frontal area of 0.7m2 (same air pressue, same everything)
The power required to ride at 28.8kph is 180.5 watts
The difference between an effective frontal area of 0.4.m2 and 0.7m2 is 47.1 watts - huge. 35.3%
Now lets bump the speed up to 12m/s or 43.2kph
Frontal area of 0.4m2 requires 317.8 watts for 42.3kph
Frontal area of 0.7m2 requires 476.7 watts for 42.3kph
Different of 158.9 watts - also huge. 50% difference in required wattage.
Proportionally as the speed requires the difference in frontal area between TT and road becomes higher as a percentage difference but there is still a 35.3 percent saving to be made at slow speeds by optimising your bike position.
This cannot be done on a road bike without having a huge impact on your running at the very least.
For the record a frontal area of 0.4m2 is only okay for a TT setup.0 -
You may feel this is "bull****" but would love to see what evidence you base this on
You yourself state that very few people go under 60 mins for 25 miles , so what part of my reasoning is it that you have an issue with.
Emmm I think I've done more than feel its bullsh!t. I think I've proved it
Very few people go under 60 minutes in the bike leg for triathlon - why? A few reasons:
* The bike legs are rarely accurate.
* The road surfaces are generally terrible
* Better to bike 1:00:30 and run 35:00 than bike 0:59:00 and run 38:00
* Finally and most importantly the majority of triathletes are poor time trialists (and bikers).0 -
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Thanks for all the info guys. But it is a hot debate on the web, road bikes vs with road bikes with aero bars v's TT bikes. Both arguments are very interesting.Emmm I think I've done more than feel its bullsh!t. I think I've proved it
Very few people go under 60 minutes in the bike leg for triathlon - why? A few reasons:
* The bike legs are rarely accurate.
* The road surfaces are generally terrible
* Better to bike 1:00:30 and run 35:00 than bike 0:59:00 and run 38:00
* Finally and most importantly the majority of triathletes are poor time trialists (and bikers).0 -
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Emmm I think I've done more than feel its bullsh!t. I think I've proved it
Nice stat's
What you've proved is that using the analytical cycling model power/speed model shows a difference in power needed to maintain speed with differing effective frontal area!
The reasons I don't but this is that there is no proof here that the OP cannot get as good an effective frontal area on a road bike with aero bars.
The most important variables in decreasing effective frontal area are as I understand it a flat torso, keeping elbows narrow in a tuck position and cycling with the knees as close to the top tube as possible.
Also on a TT /tri bike to maintaining power output (which have been shown to decrease with a more "aero "position the saddle has to be moved further forward. This make the bike more unstable . As TT bikes are more unstable and difficult to ride any way a road bike would be a better choice here IMO. As Scottreynolds says a road bike would give better options in terms of training in groups or clubs. As Tunney's himself says triathletes are not famed for their bike control skill's
I do have to admit I know little about the effects of cycle position on the run in triathlon but there is aother forum for that
But I feel the best comment here so far wasthebouldwhacker wrote: »Jezz chill out guyz, the bikes are fab I don't think this is the pissing contest thread....0 -
Stupid newbie cyclist question, but what the hell is frontal area? Also, are the stats that you quoted based on a study tunney or are they just well known? Cheers
Effective frontal area is a measure of how "aero" your position is.
Tunney used this calculator on analytical cycling .com I believe, It's been a link on the Swords cc site for the past few years
http://www.analyticcycling.com/ForcesPower_Page.html0 -
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Well, frontal area is only one component of drag, the other being coefficient of drag (CD).
Unless you're a balloon, you can't really alter your frontal area without altering your Cd.
CdA would be more useful, since it represents both and is directly related to drag force at a given speed.
TBH thats a lot more accurate than my comment
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very educational day today By tomorrow we will have nailed a formula
I see getting a road bike and fitting aero bars are pretty popular, but there isn't any bike clubs near me. If there is an advantage of a TT bike than i definitely would like it, but I know for a beginner it may not make any difference. As they say for lucozade.....makes TOP ATHLETES go 33% longer.
Im going to go to wheelsworx and cyclesuperstore to have a fitting (hopefully tomorrow).
Thanks for all the great info...keep it coming,
By the way, I'm gona throw this in for good measure: (Hopefully the matrix will be in better form today
2007 Cervelo P3C 58cm Triathlon / TT w/ SRAM Force
http://i3.ebayimg.com/08/i/001/39/8f/7fff_1.JPG
http://i5.ebayimg.com/02/i/001/39/8f/8735_1.JPG
http://i12.ebayimg.com/04/i/001/39/8f/836e_1.JPG
http://i12.ebayimg.com/05/i/001/39/8f/89c3_1.JPG
This is a 2007 Cervelo P3C 58cm Triathlon / TT bike with SRAM Force componentry, w/ ceramic upgrades. The Frame has been lightly used, however the componentry is brand new, never ridden. I built it up for the season, but things have changed. The cervelo P3C holds the title for these MOST aerodynamic frame, behind the P4 that is. It has won countless awards, took both Gold Medals in the Beijing Olympics while taking 4 of a total of six medals. This is the frame as the current P3's but with a different paint scheme. Nothing else has changed.
The build is as follows: Sram Force front derailleur, rear derailleur, crank w/ ceramic GXP bottom bracket, front and rear brake calipers. Sram 900 carbon shifters. Profile design T2+ aerobar extensions. Cervelo basebar. San Marco Ponza saddle. Easton Circuit wheelset.0 -
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Nice stat's
What you've proved is that using the analytical cycling model power/speed model shows a difference in power needed to maintain speed with differing effective frontal area!
The reasons I don't but this is that there is no proof here that the OP cannot get as good an effective frontal area on a road bike with aero bars.
But can they get a small frontal area while in a position to maintain power output? Studies have shown that closing the angle of the hip reduces the power output. Personal experience also backs this up.The most important variables in decreasing effective frontal area are as I understand it a flat torso, keeping elbows narrow in a tuck position and cycling with the knees as close to the top tube as possible.
Also on a TT /tri bike to maintaining power output (which have been shown to decrease with a more "aero "position the saddle has to be moved further forward. This make the bike more unstable . As TT bikes are more unstable and difficult to ride any way a road bike would be a better choice here IMO.
But a TT course generally is a flat, non-technical course. They aren't any more difficult to ride than a road bike if the fit is good.I do have to admit I know little about the effects of cycle position on the run in triathlon but there is aother forum for that
But a poor bike position also has huge effects on bike performance. A good aero position would also allow the power generated to be close to that of a road position. I doubt this can be replicated on a road bike without a fast forward seatpost (i.e. turning the road bike geometry into a tt bike geometry)0 -
Effective frontal area is a measure of how "aero" your position is.
Tunney used this calculator on analytical cycling .com I believe, It's been a link on the Swords cc site for the past few years
http://www.analyticcycling.com/ForcesPower_Page.html
Aye - the one I normally use is down.0 -
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Not strictly relevant to this thread but check this shit out...
I'm not sure how the new UCI rules as to 3:1 ratios for profiles are applied, or to what parts of the bike, but that can't be legal.
article here
nearly two dimensional ffs. Love it.
my 2c on topic:
aero maths and pissing contests aside, no one should only own a TT bike. Get a road bike and put the miles in. You can get clip on aero bars and a zero offset/forward seatpost if you really want mimic the aero position of a TT bike. Buy a TT bike if you deserve one in a year.0 -
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