Props to Trek for posting.
Very interesting stuff and cool to see a project come to life. Sure to be lots of discussion on here!
What are you talking about?
Link??
I’m on my phone so I can’t link. But check the front page! On the right side. All about the Speed Concepts development.
shoulda made note of the link earlier!
On the ST home page:
http://www.slowtwitch.com/Tech/Trek_s_White_Paper_2.0_-_The_Speed_Concept_1361.html
H
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yep thanks guys, found it a while ago, interesting reading.
Good read. One thing I did notice is that in all off the non-Trek drag tests that a Trek bike was not represented. Is it because the other companies didn’t want to test their bikes against a known better frame (somewhat proving Treks data) or did trek not want their name on those tests?
Sure seems like Trek is doing all the right things.
Does anyone know the patent application # for the patent/s referred to in the white paper? I poked around USPTO.gov a little bit looking for it, but it’s not always easy to guess the title of a patent application because it rarely incorporates the marketing name for the end-product.
Anyway, I’m curious to see how much of the Kamm tail design Trek’s lawyers think is patentable when applied to bicycles.
Good info. I’m not too fond of the testing on the various shapes of tubes. It seems like they may have played with the size of the shapes a bit. How do you equalize a shape for stiffness? Also I’m curious what everyone thinks about the dimpling part. It makes it sound like selective dimpling is good, at least for a round shape.
Styrrell
We don’t discourage other companies from including our products in their testing. Product availability is an often overlooked factor, since product cycles across models & companies rarely line up and hot stuff sells thru quickly. Other than that, what they test and what they show is entirely up to them. To quote another Carl (Sagan): “absence of evidence is not evidence of absence”.
Carl
After reading the Trek whitepaper - and looking at the different graphs - is it possible to determine how the top of the line Speed Concept would compare to the Shiv?
Dave Linenberg
After reading the Trek whitepaper - and looking at the different graphs - is it possible to determine how the top of the line Speed Concept would compare to the Shiv?
Dave Linenberg
You can compare the Trek to the Transition, and then base off that. However, it’s worth noting that the shape of Trek’s data for the Transition is markedly different than Specialized’s published data for the Transition as yaw increases. The same is true with the shape of the P4 drag. The shape of several other bikes data plots more closely resembles the data produced by other companies - the Felt, for example. But I’d be wary of doing the apples: oranges, oranges:pears sort of comparison. You can see - as all three charts are published in the graph - the difference between Trek’s data, Cervelo’s data, and Specialized’s data. I’m not saying that any one set is better or worse. Just pointing that there are some significant differences, not just in the drag #s, which you’d expect, but in the actual shape of the graphs.
We don’t discourage other companies from including our products in their testing. Product availability is an often overlooked factor, since product cycles across models & companies rarely line up and hot stuff sells thru quickly. Other than that, what they test and what they show is entirely up to them. To quote another Carl (Sagan): “absence of evidence is not evidence of absence”.
Good stuff Carl! Lots of good reading and insight into the engineering that went into the Speed Concept.
After my first quick read, I’ve got a couple of initial questions I was hoping you could address:
First, can you explain why the shape of the curves for the non-Trek bikes changes so much between the 2009 and 2010 tests? I understand why the SC curve might change (due to design refinements) but why would the other bikes change so much? Specifically, I’m talking about the Cervelos and the Transition.Second, why only yaw in one direction (with wind hitting the DS)? As can be seen in the Cervelo and Specialized data you present in the Appendix of the paper, the drag data can be significantly different depending on the yaw angle. That can affect your predicted time saving calculations, no?
After reading the Trek whitepaper - and looking at the different graphs - is it possible to determine how the top of the line Speed Concept would compare to the Shiv?
Dave Linenberg
You can compare the Trek to the Transition, and then base off that. However, it’s worth noting that the shape of Trek’s data for the Transition is markedly different than Specialized’s published data for the Transition as yaw increases. The same is true with the shape of the P4 drag. The shape of several other bikes data plots more closely resembles the data produced by other companies - the Felt, for example. But I’d be wary of doing the apples: oranges, oranges:pears sort of comparison. You can see - as all three charts are published in the graph - the difference between Trek’s data, Cervelo’s data, and Specialized’s data. I’m not saying that any one set is better or worse. Just pointing that there are some significant differences, not just in the drag #s, which you’d expect, but in the actual shape of the graphs.
Heck…the shape of the non-Trek bike drag curves isn’t even consistent across Trek’s own tests…
After reading the Trek whitepaper - and looking at the different graphs - is it possible to determine how the top of the line Speed Concept would compare to the Shiv?
Dave Linenberg
You can compare the Trek to the Transition, and then base off that. However, it’s worth noting that the shape of Trek’s data for the Transition is markedly different than Specialized’s published data for the Transition as yaw increases. The same is true with the shape of the P4 drag. The shape of several other bikes data plots more closely resembles the data produced by other companies - the Felt, for example. But I’d be wary of doing the apples: oranges, oranges:pears sort of comparison. You can see - as all three charts are published in the graph - the difference between Trek’s data, Cervelo’s data, and Specialized’s data. I’m not saying that any one set is better or worse. Just pointing that there are some significant differences, not just in the drag #s, which you’d expect, but in the actual shape of the graphs.
Heck…the shape of the non-Trek drag curves isn’t even consistent across their own tests…
HED 3 in front, stops/decreases the stall past 15deg for most bikes
Xav
HED 3 in front, stops/decreases the stall past 15deg for most bikes
Aaah…I didn’t catch that front wheel change between the 2 tests. I guess that means I shouldn’t plan on using an Aeolus 9.0 on my Transition 
Manny’s seat is too high 
.
Manny’s seat is too high
Of course it is…didn’t they say that they scanned a “typical triathlon position”?
BTW, I forgot to add above, using the articulated mannequin is a great idea.
Thanks Tom!
First off let me say that Paul Harder deserves the lion’s share of the credit - and then some - for pulling the content together into the package you see today.
Setup changes (and wheels are major players) account for “same” bike/different curve disparities…regardless of make or model.
DS-only sweeps are, in our case, primarily based on efficient use of tunnel time. It is the most aerodynamically “busy” side of the bike with respect to what’s presented to the wind, and thus the most interesting to us. As for how including NDS data might affect the predicted time savings calculations, I’d expect it to result in a slight offset from what we presented, but no significant change in the curve shape other than flattening out the peaks a bit.
Carl
Funny that the worst performing bike in their testing was my bike (Felt B2). Of course, being the moron that I am, I drove mine into the garage without taking it off of the bike rack this week and it is now destroyed. The best Felt will do for crash replacement is to sell me a 2010 DA frame for $3K, AND I have to wait 60 days to get it. Wow, such a deal. Hmmmm, I think it is Speed Concept time. See ya Felt, it was nice knowing ya once I fixed the Bayonet I on my old bike because your dealers didn’t know how to install it correctly. I won’t have to worry about that anymore.
Trek is about to DESTROY the tri bike market, the SC will shatter it into a thousand pieces. Trek will be selling thousands of these things to Team In Training members as well as AG winners. Ironman racing is a huge market and if it can give you 8-10 minutes over that distance, people are going to pay. Kudos to them for doing the right thing, making a TRI bike and adapting it to their pro cycling teams rather than doing it the other way around. Not a big market for UCI-legal TT bikes after all.
For those who doubt the research in this paper, hey at least Trek has done some and put it out there. Most manufacturers don’t do anything like this. Specialized and Cervelo being two exceptions of course but it looks like Trek has leapfrogged them for now.