Login required to started new threads

Login required to post replies

Prev Next
Trek TTX is Faster Than the P3C
Quote | Reply
Well, according to a very simple graph that Chris Lieto posted on his Kona blog.



http://lietokonadiaries.blogspot.com/

Shawn
TORRE Consulting Services, LLC
http://www.TORREcs.com

Quote Reply
Re: Trek TTX is Faster Than the P3C [ShawnF] [ In reply to ]
Quote | Reply
As a TTX rider, this is nice to see. However, without ANY configuration data, it's less useful. I.e., you don't know what bottles were or were not on the frame. What wheels, etc. I hope he provides some more info. Otherwise, it's just marketing speak, as much as I'd like to stand up and shout "yes." The TTX is a very well designed, very well executed frame. I think at the very least, you can take away that it is among the very best frames in the world. I think there is a clear group of frames at the top, and the TTX and P3C are both part. The Scott Plasma, it appears, is not. Based on a very cursory inspection of the downtube and headtube of all thread bikes, I will say that it doesn't surprise me a whole lot. There are some very simple, very fundamental rules of aerodynamics that you need to follow. If you follow them, you'll do well. Some companies do this in house with CFD and lots of windtunnel testing. Others do it by just copying the tubes of the companies that spend that money. And others still don't, for whatever reason, do this at all, something which I fail to understand.

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp
Quote Reply
Re: Trek TTX is Faster Than the P3C [Rappstar] [ In reply to ]
Quote | Reply
Hey Rappstar, how much will the way the rider's body affecting the airflow change the raw bike's aerodynamics. I'd imagine that is completely possible that riding knees in vs knees apart could affect the relative benefits of a P3C type cutout vs some other bike. Also, if I recall correctly, John Cobb once showed that when riding a softride it was better to go downhill in a tuck with your knees actually clamped to the top tube/beam but instead apart. The idea was that the air could reattack better behind the legs when apart than when together touching the top tube. Of course, this would not apply to a conventional bike, however it goes to show that rider position and style might also affect the aero benefits from one bike vs another, adding to or negating a particular bike's positive qualities?
Quote Reply
Re: Trek TTX is Faster Than the P3C [ShawnF] [ In reply to ]
Quote | Reply
haha sweet, my Madone is only ~50g less aero than a Scott Plasma.
Quote Reply
Re: Trek TTX is Faster Than the P3C [devashish paul] [ In reply to ]
Quote | Reply
In Reply To:
Hey Rappstar, how much will the way the rider's body affecting the airflow change the raw bike's aerodynamics. I'd imagine that is completely possible that riding knees in vs knees apart could affect the relative benefits of a P3C type cutout vs some other bike. Also, if I recall correctly, John Cobb once showed that when riding a softride it was better to go downhill in a tuck with your knees actually clamped to the top tube/beam but instead apart. The idea was that the air could reattack better behind the legs when apart than when together touching the top tube. Of course, this would not apply to a conventional bike, however it goes to show that rider position and style might also affect the aero benefits from one bike vs another, adding to or negating a particular bike's positive qualities?

It's certainly possible. I'm definitely not any sort of authority of rider/frame aerodynamics (frame aerodynamics are governed much more by the fundamentals of aerodynamics, whereas the rider/frame interaction is something where there is no real substitute for just going to the tunnel). But things could certainly be affected. For instance, Lieto rides very slack, so perhaps his legs are in a different position relative to the seattube than say Dave Zabriskie's on the P3C, where Dave is sitting way on the nose of the saddle. So this might, as a total guess, affect the airflow around the seattube, which might reduce some of the effectiveness of the P3C's shape there. If you go by the theory that the P3C is designed to be ridden steep, I'd also be willing to give Gerard the benefit of the doubt that they focused on the aerodynamics of a rider in such a position. I can imagine, though I want to emphasize that this is total guessing, that if the P3C is optimized geometrically for steep riding, it may also be optimized aerodynamically. The Trek is also designed to be ridden steep, but perhaps not to quite the same extent, so perhaps the aerodynamics of the frame work better with someone who rides slack. The geometries are close, but not identical, so it's certainly reasonable, I think, to infer that there may be a "right bike" for a rider based on fit, and then furthermore based on aerodynamics. I.e., if you know that 4 or 5 of 10 high-end bikes work with your position geometrically, you might further be able to refine that number down with windtunnel testing to the one or two bike(s) that are basically a perfect match. I believe they did this with David Millar's (tainted) World TT win. They built the bike entirely around him, both in terms of geometry, and in terms of tuning the aerodynamics around his position (at least, that is how I interpreted the article I read on the project).

"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp
Quote Reply
Re: Trek TTX is Faster Than the P3C [Rappstar] [ In reply to ]
Quote | Reply
Thanks, I just wanted the aero gurus to confirm that rider position on an aero bike can affect the "aero contribution" of the bike itself.

I'm taking a wild shot here, but I'd wager to guess that the further apart your knees are, the more the benefit of the aero cut. Bring the knees in and there is no laminar air hitting the aero cutout, however, you are punching a smaller aggregate hole in the wind, so overall Cda might be better even though contribution for the aero cutout is now substantially reduced. Just a guess.

Dev
Quote Reply
Re: Trek TTX is Faster Than the P3C [devashish paul] [ In reply to ]
Quote | Reply
Number one...will you all please stop letting science get in the way of our purchases!


Second...I am willing to bet that the person to win Kona will be the one who is most fit...no matter what bike they ride....


Three...golly jeepers I hope it is Pink!

----------------------------------------------------------

What if the Hokey Pokey is what it is all about?
Quote Reply
Re: Trek TTX is Faster Than the P3C [Record10Carbon] [ In reply to ]
Quote | Reply
I agree, that being said, wh was the world TT champs won on a p3c???? :)


In Reply To:
Number one...will you all please stop letting science get in the way of our purchases!


Second...I am willing to bet that the person to win Kona will be the one who is most fit...no matter what bike they ride....


Three...golly jeepers I hope it is Pink!
Quote Reply
Re: Trek TTX is Faster Than the P3C [ShawnF] [ In reply to ]
Quote | Reply
With the P3C, TTX, BMC, or DA how much are they just splitting hairs as to which is the fastest bike? Intentionally omitted Specialized, Ordu, new Slice, Willier since they are very new designs and haven't seen any data or anecdotal evidence on them. Walser could probably be added but was not because to the best of my knowledge is not a mass production design ( Is mass production of a niche market a real term?)

Also, you seem to know a few people, is the Bontrager bottle on the front of Lieto's bike a one off, pre-production, test, Dremel-mod?

---------------------------------------------------

Brawndo's got what plants crave. Brawndo's got electrolytes. And that's what plants crave. They crave electrolytes. Which is what Brawndo has. And that's why plants crave Brawndo. Not water, like from the toilet.
Quote Reply
Re: Trek TTX is Faster Than the P3C [Record10Carbon] [ In reply to ]
Quote | Reply
In Reply To:
Second...I am willing to bet that the person to win Kona will be the one who is most fit...no matter what bike they ride....

Really!?!

So you suggest that I might benefit more from better/harder/smarter training than from buying "fast" bikes?
Why wasn't that absolute brand-new never-heard-before information available earlier in my triathlon life?
That would have saved me buying all those expensive bikes.

Frank

I've seen things you people wouldn't believe. Attack ships on fire off the shoulder of Orion. I watched C-beams glitter in the dark near the Tannhauser Gate. All those moments will be lost in time like tears in rain.
Quote Reply
Re: Trek TTX is Faster Than the P3C [Rappstar] [ In reply to ]
Quote | Reply
this article states the data is from a wind tunnel test of Levi Leipheimer on Feb. 26th, 2007.

http://www.bikeradar.com/...x-99-ssl-12746?img=2

Low Speed Wind Tunnel test figures based on Levi Leipheimer's February 26, 2007 wind tunnel run (Trek©.)

Quote Reply
Re: Trek TTX is Faster Than the P3C [Hamner] [ In reply to ]
Quote | Reply
In Reply To:
With the P3C, TTX, BMC, or DA how much are they just splitting hairs as to which is the fastest bike? Intentionally omitted Specialized, Ordu, new Slice, Willier since they are very new designs and haven't seen any data or anecdotal evidence on them. Walser could probably be added but was not because to the best of my knowledge is not a mass production design ( Is mass production of a niche market a real term?)

Also, you seem to know a few people, is the Bontrager bottle on the front of Lieto's bike a one off, pre-production, test, Dremel-mod?

The bottle and cage are both available now. I can't tell if that is a new cage designed to be bar mounted, or if it is a custom fit...

In any event, it looks pretty cool!

______________________________________________
DING DING!! Artmus speaks the truth!
100 miles a day is the only power meter you need.

Quote Reply
Re: Trek TTX is Faster Than the P3C [ShawnF] [ In reply to ]
Quote | Reply
The stats are not for the TTX, but rather the new TTX SSL. Levi and company looked pretty good on them on the way to Paris. Chris has one too. Not many other people, unless it says prototype on it. The SSL has 300 grams less frame weight than the 9.9 TTX. That's pretty good fine tuning of a proven fast product. It is hard to get one though, and the price reflects that the Waterloo factory is not going to make many. But it does show me that the 800 lb. gorilla in cycling is not resting. When Porsche finishes up a model year production run, the marketing dept. throws all kinds of horsepower and performance specials into a special "S' model to enhance the brand status and give the company engineers a chance to show their stuff when startup model costs have long been paid for. I think Trek is not betting on a $8200 bike to add to their bottom line, but has created a flagship to help TTX 9 series sales late in their production run. They are great bikes, backed by a company that stands behind it's product. I wish Chris the best in Kona, and I am rooting for him and Trek.

------------------

_____________________________________________
"The trick, William Potter, is not minding that it hurts." T.E. Lawrence
Quote Reply
Re: Trek TTX is Faster Than the P3C [ShawnF] [ In reply to ]
Quote | Reply
These data remind me of Gerard's comment that "we're always happy to finish 2nd in tests paid for by other manufacturers". :-)
Quote Reply
Re: Trek TTX is Faster Than the P3C [ShawnF] [ In reply to ]
Quote | Reply
To say a bike is fast is to imply the bike propels itself, which is absurd.

NEXT!
Quote Reply
Re: Trek TTX is Faster Than the P3C [T3] [ In reply to ]
Quote | Reply
In Reply To:
The stats are not for the TTX, but rather the new TTX SSL.

Ummm...aerodynamically speaking (i.e. the "stats" shown in that plot), the TTX and TTX SSL will be identical.

http://bikeblather.blogspot.com/
Quote Reply
Re: Trek TTX is Faster Than the P3C [synchronicity] [ In reply to ]
Quote | Reply
I'm constantly amazed at the resiliency of these threads on ST. Bottom line: the difference in aero performance of the top bikes is negligible, and more than canceled out by body position and/or the strength of the rider. So why must we continue to post wind tunnel tests, charts graphs, etc. when it really doesn't matter? Is it because it's the off-season?
Quote Reply
Re: Trek TTX is Faster Than the P3C [T3] [ In reply to ]
Quote | Reply
300 grams less for the frame? Frame was not really heavy to begon with. As I recall a little over 1400 grams. But the 660 gram fork??? Did they do anything about that?
Quote Reply
Re: Trek TTX is Faster Than the P3C [Large] [ In reply to ]
Quote | Reply
In Reply To:
I'm constantly amazed at the resiliency of these threads on ST. Bottom line: the difference in aero performance of the top bikes is negligible, and more than canceled out by body position and/or the strength of the rider. So why must we continue to post wind tunnel tests, charts graphs, etc. when it really doesn't matter? Is it because it's the off-season?

IMO, it's because doing well in timed cycling events ( i.e. TTs or Tri bike legs) is ALL about attention to a BUNCH of little details. This is one of those details. It's up to the person looking at the numbers to decide if they are significant enough to worry about. They, and they alone, get to decide if it "matters".

Personally, I'm constantly amazed at how many people think that none of this stuff "matters" ;-)

http://bikeblather.blogspot.com/
Quote Reply
Re: Trek TTX is Faster Than the P3C [ShawnF] [ In reply to ]
Quote | Reply
So many variables in something like this that the information needs a lot of qualification- for either manufacturer.

One of the predominant factors is selecting a bike a rider can acheive an aerodynamic and efficient (watts vs. heart rate, etc) on. Then there are the variables of comfort and what affect that may/may not exert on the riders real performance on the road. A bike can be more efficient and more aerodynamic but if a rider is distracted by saddle discomfort by something as simple as a poor saddle choice that is likely to cost them time when they don't even realize it.

It concerns me when people try to grasp at informational straws like "which bike is more aero- here's a cool computer generated graph that "proves" it".

For us real people, the people on the sales floor selling and buying the bikes, it is key to remember a few things:
  • If you don't feel comfortable on the bike, it will be difficult to focus on remaining still and putting in a good effort.
  • When we are grinding up a steep hill at the local triathlon or on the bike course at Lake Placid, Wisconsin, Wildflower, St. Croix or whereever and going 9 m.p.h. with our hands on the base bars seated upright trying to save a few precious seconds on a climg aerodynamics is a greatly diminished factor: Other issues like fit, frame stiffness, crank and component selection, pedal set up, tire choice become more important concerns in the real world.
  • We don't have wind tunnels to develop the optimal position, so what is the easiest bike to get a resonable position that is a good mix of aerodynamic, comfort, power and with good bike handling? That answer may vary from person to person contingent on size, dimensions, riding style, level of experience and fitness.

So many things go into what makes a bike optimal for a given individual. No one truly understands how all the variables interact. fixating on one aspect of the bike's performance (aerodynamics in this case) is an interesting and worthwhile discussion, but one that should be kept in perspective against the other factors that influence the performance of the bike/rider package.

Tom Demerly
The Tri Shop.com
Quote Reply
Re: Trek TTX is Faster Than the P3C [Tom A.] [ In reply to ]
Quote | Reply
In Reply To:
Personally, I'm constantly amazed at how many people think that none of this stuff "matters" ;-)
It's not that none of this stuff matters, it's that there is a point of diminishing returns. Once you get into the 5 or so most aero bikes, the difference between the aerodynamics of the frames is less important than whether someone rides with their knees inward or outward, etc. At that point, whether one riderless frame does .2% better in a wind tunnel (or other test) than the other is essentially meaningless.
Quote Reply
Re: Trek TTX is Faster Than the P3C [Large] [ In reply to ]
Quote | Reply
It happens with all equipment based hobbies, part of the fun.

I remember reading years ago about a car race series. You had to buy a specific car and couldn't do any modiifications. You could take apart the car and do anything you wanted as long as the original parts met the manufacturers original specs for that part. One team consistently dominated year in year out, with different drivers. This was also the team owned by a machine shop owner who put 1000s of hours in to rebuilding the car. Every part was lightened to the bottom of the acceptable limit, polished balanced etc. Nothing they did was a big deal on any 1 part, but it all adds up.

Take the second most aero bike with the second best rolling tires, the second most aero wheels, the second heaviest drivetrain, the second fastest wet suit, second lightest shoes, etc and race against someone with the fastest / best of everything and, assuming you are relatively well matched, I know who I'm betting on.

Of course its not going to turn a mid pack ito a top tier guy.

Styrrell
Quote Reply
Re: Trek TTX is Faster Than the P3C [Tom A.] [ In reply to ]
Quote | Reply
In Reply To:
In Reply To:
I'm constantly amazed at the resiliency of these threads on ST. Bottom line: the difference in aero performance of the top bikes is negligible, and more than canceled out by body position and/or the strength of the rider. So why must we continue to post wind tunnel tests, charts graphs, etc. when it really doesn't matter? Is it because it's the off-season?

IMO, it's because doing well in timed cycling events ( i.e. TTs or Tri bike legs) is ALL about attention to a BUNCH of little details. This is one of those details. It's up to the person looking at the numbers to decide if they are significant enough to worry about. They, and they alone, get to decide if it "matters".

Personally, I'm constantly amazed at how many people think that none of this stuff "matters" ;-)
Spoken like a real 'watt trader', Tom.....

Is it just me, or do those drag numbers not add up for a 130lb TT specialist??
Quote Reply
Re: Trek TTX is Faster Than the P3C [Large] [ In reply to ]
Quote | Reply
In Reply To:
the difference in aero performance of the top bikes is negligible, and more than canceled out by body position and/or the strength of the rider. So why must we continue to post wind tunnel tests, charts graphs, etc.
Aside from "the devil is in the details" argument, there's also the fact that we wouldn't know that the differences between the very best aero bikes are quite small if the data were never shared.
Quote Reply
Re: Trek TTX is Faster Than the P3C [smtyrrell99] [ In reply to ]
Quote | Reply
In Reply To:
It happens with all equipment based hobbies, part of the fun. . . . .

Thousands of years ago, when our species was still evolving, obsessive and persistent acquisition of the very best weaponry (spears, clubs, arrows, etc.) was a trait that had tremendous survival value. For example, with a slightly improved spear, you could overwhelm an otherwise vastly superior foe, armed with the old, non-dimpled spear. So this trait was honed and bred into us through natural selection. Thus, in modern-day sport (i.e. sublimated warfare), it's only natural for us to hew to this strongly imprinted trait.


-jens
Last edited by: jens: Oct 10, 07 9:08
Quote Reply

Prev Next