Jordan,
I sent you a note. :-)
Thanks
H

girl, with those cranks and full dura-a on the lucero, plus custom fit...you'll fly like mad. like i say--things happen for a reason...i agree with rroof on the lucero positioning. it will be you, just faster. ;)

Well, that's good to know. I do value your assesments a lot. Frame aerodynamics alone is definitely "overrated" ;), but I am also so fed up with things like the Cannondale. It seems like they are working harder to make a bike that uses un-aero tubes, when it would be just as easy to make those tubes something as a simple NACA foil.

My point was NOT that the Lucero is not an aero-bike. It very well may be, and I certainly have a lot of confidence that is much more aero than the Cannondale and other bikes of that ilk. It was more along the lines that there's nothing published. Of course, such "published" works are to be taken with a grain of salt. But I do like the idea of presenting such data to the consumer. I think it does force some level of accountability into the mix and prevents "aerodynamics" from becoming the next iteration of the "comfort-improving" carbon rear triangle.

Herbet was kind enough to share his knowledge that John Cobb and Steve Hed influenced the design, and that carries a lot of weight in my book. I would definitely feel much better if I was astride a Lucero with that knowledge in hand.

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

The quality for both bikes is good whichever way you go.

In the end, go with comfort. I test rode both bikes and decided to go with the Lucero because it FIT me much more comfortably. The P3C rides low on the front end compared to Lucero and my body's geometry doesn't allow me to maintain an efficient position over the longhaul in such a low/flat position. I'm just not comfortable at the lower angles. But either way, base your decision on FIT more than the price because either at 4k or 5k, you want to make sure you get the bike which fits you the best..

Who brought the Cannondale to the discussion??? I know... YOU! ;-)



Seriously, we were comparing the P3C and the Lucero. Both bikes are not bogus aerodynamic, are truly aerodynamic. One has wind tunnel data, I think supplied by the manufacturer, the other doesn't. In this case, to me, that seems irrelevant.

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

well the problem is that I can't find a lucero to test ride. So I have to just assume it would fit...

Herbert, can you please find poor Sophie a 48cm Lucero to test ride. I know you wouldn't want her buying a QR without testing one first.

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

I personally much prefer the looks of the Lucero over the P3C. But if it was my choice I'd go for the P2C - at even a better price than the P3C.

"From inspecting the two frames, I am pretty confident that the Lucero is as aerodynamic as the P3C."

I've had a few aerodynamics courses, but I wouldn't venture too far if pressed on which bike is more aerodynamic. How exactly are you so confident, based on what you know about aerodynamics? I've never inspected them, but even if I did, I'm not so sure that would give me that much information.

I'm curious what I missed out on...

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"What the mind can conceive and believe, the mind and body can achieve; and those who stay will be champions."

>Also, I remember this summer you posting some pics with some recs and everyone said to lower your front-end. I think you ended up not doing it if I'm not mistaken<

>Since you have already qualified for Kona and are likely to do so again, I'm not sure why you want to change much.<

Well said and something not to be taken lightly.

So based on the aero courses you've had, can you tell me a bit about the main features of the flow around a bike frame. That should be a good starting point to have a good qualitative theoretical discussion.

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

"the Lucero’s multi-layered carbon fibers are molded with state of the art resin pregnation system" (from rooworld.com).

Is this similar to what Time used for the RXR and Hed uses for the H3 -- "resin transfer molding"?

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

The Caliente appears to be a pretty reasonable value when compared to the P3C and Lucero. I am not sure there is that much difference/justification for the big jump in price from Caliente to Lucero (as you say, same frame). I am looking at Caliente vs P3C. I haven't rode a Caliente but did try a P3C in a 54. Unfortunately the bike shop doesn't have the bike set up the way I plan on riding it and didn't offer to adjust. My current seat is 4 inches above my handlebars (road bike with aero bar clipons) and I would like to train myself to get lower. I wonder if the Caliente can be adjusted for a handlebar drop of 5 or 6 inches below the seat. I am 5'8" barefoot with 31 inseam and I am told a 54 inch P3C is what I should buy. I am concerned that it might be a bit too large but the 51 would be too small.

Not trying to hijack the post but fit and riding positions are important when considering these two.

Well, hopefully no one will mind the hijack.

So, I guess a lot of it depends on the exact configuration - I'm not sure if you're talking about the frame by itself or the frame built up. So, assuming you mean the frame built up, it's of course going to depend on the exact type of wheels, handlebars, downtube, etc.

The main features I see are mostly clean flow hitting the front of the bike (although there are of course upstream propagation of disturbances due to the bike), and after that, a whole multitude of areas where the flow can become detached and develop some complicated wake structures. It depends on how well the flow stays attached coming off the wheels/fork/aerobars/brakes/headtube/cables to determine what happens after that.

Is that what you were asking?

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"What the mind can conceive and believe, the mind and body can achieve; and those who stay will be champions."

"My current seat is 4 inches above my handlebars (road bike with aero bar clipons) and I would like to train myself to get lower. I wonder if the Caliente can be adjusted for a handlebar drop of 5 or 6 inches below the seat. I am 5'8" barefoot with 31 inseam and I am told a 54 inch P3C is what I should buy. I am concerned that it might be a bit too large but the 51 would be too small."
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Sounds like you have the same body proportions as I do, and we're about the same height. I personally wouldn't consider the 54 P3C as I compared the 54 and 51 at IMC and the 54 was too long in the top tube with a longer head tube to boot.

But to put this marginally back on topic, with your body type it's harder to get a lower front end, so you need to know more about your tri position and what bars you're likely to use. I thought I rode low because I had a zero rise stem and no spacers on my old P2 (not P2K), but then when I changed bars from Syntace C2 to VisionTech R-bends the front end was too low and I needed the larger risers and a small spacer. I'm in the market for a new bike now, and with those factors in mind the bike with the lower front end (with my budget it's the P2 SL) probably isn't what I need, so I'm looking at QR and Guru over Cervelo right now.

I think you're overthinking it a bit. Basically, you can toss out the effect of the wheels between each bike, since you can ride the same wheels on each.

So you need to look at fork & headtube -> downtube -> seattube (both shape and how it interacts with the rear wheel) -> seat stays. That is the progression.

So then based on experience and knowledge, you can get a good look at the leading edge, trailing edge, and basic cross sections of each of those areas. That should be enough if you know your stuff to make a reasonable ballpark judgement.

Paulo is a PhD level aero-engineer (not sure if the final stamp has been put on his thesis yet), so he has enough experience to make a reasonable superficial estimation of the shapes of each of those key components. Could he pick which frame is more aero? No. But he can definitely make some back-of-the-envelope judgements that would be somewhat accurate. Just like a top running coach doesn't need to watch slow-motion video to assess a runner. If you do something long enough, and Paulo has a lot of history with airfoil shapes, then you develop an eye for it.

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

Yes.

The way I see it, two main features make an aerodynamic frame: The shape of the headtube region and the shape of the downtube. We could also take into account the shape of the seat-tube, but leg movement interference is too big.

In both bikes, the head-tube area is very similar. Also the placement of the cables is similar, and it's in a region close to the separation region in that area.

Downtube is very similar too. Both use an airfoil profile. In the case of the Cervelo, it's a NACA four-digit, I don't know what kind of profile the Lucero has. Either way, the shape of the section is not very important, since it would be hard to tune a section to work better with the different conditions.

Where the two frames differ a bit is on the tob-tube. The Lucero top tube is more sensible to cross-flow due to it's bigger area and shape. But again in that region leg interference is higher.



In these two features the frames are very similar. Other frames in the market fail to have these aero features. For example, compare the downtube of these bikes with the downtube of the Kuota or the Guru, to name two other carbon "aero" frames.

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

Yes I can! ;-)



The strong point of the Cervelo is the seat tube part. But I'm not totally sure that having the seat-tube be "one" with the disc wheel is a strong point. The rotation of the disc and the shape of the seat-tube region make me think that flow is heavily stagnated in that region, and more than a traditional frame. But that's just intuition :-)

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

Isn't "fit", or lack therof the problem with your Aegis?

Haven't you been fitted on a P3 or P3C by the Cervelo folks and you liked it?

Haven't you found a shop that will have one by mid November?

You're considering buying a bike "assuming it would fit"?

I don't get it... you've been at this so long it's already almost mid-November ;-)

And you don't "NEED a bike for thanksgiving week-end... (your) offical start date for training for IMAZ"... use whatever you have until your bike comes in. Lord... lots of pros use single-speeds, road bikes, mountain bikes and probably there's one out there who uses a unicycle during the winter... my point is, if you know it fits and that's why you're getting out of your new bike, wait for the P3C, otherwise you stand a chance to be in the same boat you are now with your Aegis...

Maybe one of these days we can get a grant for you to do some tunnel testing with smoke for visualization in some of those regions. Those images would be very, very interesting... Pressure transducers in some of those areas would also be neat.

I'd also be very intrigued to see how the P3 seattube functions with a disc vs. a non-disc wheel and then to compare that to a bike like the Lucero (or P2 or Plasma) functions with a disc vs. non-disc.

EDIT: the seat-stays on the Lucero are the most notable feature of that bike. I think that shows a lot of the John Cobb influence that Herbet mentioned. Cobb did say, if I remember correctly, that he believe seat-stay design to be more important than seattube design. Be interesting to get some numbers on them...

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

These days only if you can prove you can use a P3 as a weapon or as a surveilance vehicule...

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

I agree... but windtunnel tests have shown bikes like the Softride, P3 and KM40 to be the most aerodynamic and their distinguishing feature over other bikes are that they all either have no seattube or a curved seattube... is there a testing protocol that favors those designs but is not a representation of real-world aerodynamics?

Along those lines, it'd be much easier to get funding for MTB suspension research.

I guess we just need to lean on Gerard to convince the RCAF that Bjorn is really a projectile. Then we can get some money!

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp

We're talking about different configurations here. I personally think that the stong point of the KM-40 is the distance between the downtube and the front wheel, reducing interference a lot. The softride and Zipp is IMO the very reduced interference between the disc and the frame. Now if you think the interference between the frame and the disc is big with the P3...

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

I would argue that that the big absence in those tests (less so with the Kestrel and by all accounts a non-issue with the P3) is structural. I think the Softride would do very poorly in torsional rigidity tests, somewhere that Cervelo (and Litespeed) bikes have traditionally done very well. The Softride is quite possible the most aerodynamic frame. But the losses to poor structural design make it an also-ran in real world applicability. A double-diamond frame is ALWAYS going to be much more structurally sound. The design is so mechnically sound. Much more so than the KM40's design as well. That is the big X-factor with those bikes. I would be intrigued to see if the P2C and P3C have notably different results for BB stiffness...

Cobb has also argued that seatstays are more important than seattube. So I would venture to guess that he has some data to back that up.

The P3 has also not ventured into the tunnel, I don't believe, against bikes like the new Walser or the BMC that have a non-curved seat-tube, but which still shield the rear wheel as completely.

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"Non est ad astra mollis e terris via." - Seneca | rappstar.com | FB - Rappstar Racing | IG - @jordanrapp