You had to know it was coming sooner rather than later with the Cervelo sales going on, but Inside Tri mentions they’ve glimpsed P4C prototypes:
http://www.insidetri.com/portal/news/news.asp?item=112205
The link doesn’t say anything about the P4C, but does have some interesting aero info, e.g. Stinger 90’s vs. 808’s.
Any insiders with hints they can drop re. the P4C?
Tommy D has information that I think he is holding back on. I wonder how my Jet 90s compare to the Stinger 90s. I did like the small write up they did but now as always, I am craving more information.
unless you are a engineer at cervelo, there is no info that are leaked about the new P4C. We saw many prototype last week in the wind tunnel and some had some really cool new feature that ‘‘might be improving’’ the already fast p3c. I do think they didnt show us all the prototype and we dont know witch part of witch bikes will be using for the final product…
so… keep looking… it s out there http://www.youtube.com/watch?v=7Qj2b4L_q6U&eurl=http://jonnyoworld.blogspot.com/2008/02/commercialwhy-not.html
about the p4, you don’t need to be a rocket scientist to know it is coming. folks at cervelo don’t sit on their hands, trust me. and there are other new frames coming from other companies, but if i was a betting man, i’d put my money on cervelo raising the bar that everyone else will again be chasing.
about the 808 and stinger comparison, well of course. and the main reason the stingers are slightly more aero? well, those stingers are 11-12% deeper than the 808s. (and i bet the zipp 1080s would slightly beat out those stingers.) all other things being equal, if the shape is right, the deeper the better.
Here’s my guess:
Start with the P3C:
Change the cable routing so it enters the frame behind the stem.
Either add a new front brake like the new Specialized Transition, or fare the brake behind the fork like the new Jamis bikes.
Rear brake behind the bottom bracket.
Seat stays hugging the wheel more … again like the new Specialized Transtion.
Maybe something new with the bottom bracket ala Trek Madone or Cannondale (the press-fit thing)?
Oh … here’s a great idea … HOW ABOUT A SEATPOST THAT WON’T SLIP!!!
.
My question is whether Cervelo found the HED’s are more aerodynamic as a stand alone test/in general or in combination with the Cervelo frame?
For the record, the 808 is faster with a 21mm tire by about 5 grams average and the stinger is faster with 23mm tire by about 6 grams average, but the 808 does it with ~12% less side force for better handling across all angles…not to mention the 808 is about 1/2lb lighter for the pair.
Thanks Josh, as always, very helpful. Here I was about to sell my Zipp’s b/c of a few grams of drag…whew! 
Bob
hey bob, i dont have a carbon cervelo. so, for you, is the slipping problem you are talking about the saddle tipping down (or up), or the post sliding down in the frame?
Wouldn’t 10% of that reduction in “side force” be directly accounted to rim depth? (82mm-90mm ~ 10% difference)
Just a guess. How does the 1080 compare to the 90 stinger in side force?
I can confirm there were items we saw at the wind tunnel that we were asked not to photograph or to describe. I can also confirm that none of them was a new bike in its entirety and our group was not shown anything that was described as a “P4C prototype”.
A number of things could be going on here that may include any of the following or some combination of the following. First, the facts:
At the dealer version of Brain Bike 2008 no cameras or cell phones were allowed in the wind tunnel area. A number of trial versions of specific frame components, but not a completely new frame, were displayed. No characterization of these components was made by Cervelo personnel of them being either upcoming products or prototypes that had been tested and rejected. They simply did not specifiy. When asked, Cervelo personnel politely declined to answer. I did not attend the consumer/press version of Brain Bike and do not know if different items were displayed, disclosed or discussed.
Now, my ideas:
I doubt there are current plans for a so-called “P4C” release any time soon. The reasons I doubt this include the Cervelo ethos that “It is easy to make something new, hard to make something better.” One of the prevalent themes at Brain Bike was that the P3C is so highly optimized for aerodynamics that only very small changes will net an improvement, and the improvement would likely be relatively minor. As it is already a category leader, there is little need for change at this time. The incessant rumors about a “P4C” aren’t good for Cervelo and Cervelo dealers. People considering the purchase of a current P3C may be compelled to wait for a product that, as yet, doesn’t exist officially. While I love Cervelo, buy them and sell them and consider their staff friends of mine, they (by their own admission) have opportunities to improve in the area of order fulfillment. Simply put, they could find ways to ship bikes faster. The introduction of a new model may undermine that effort. People are still waiting for delivery on current models. Introducing something new at this point would only make things more complex, even if it did exist. That said, no doubt *new ideas do exist. *Cervelo is not standing still and they are continuously moving forward with refinements and ideas. The decision on when to release those ideas as finished product is a strategic one made by Cervelo based on a number of factors only they are privy too. The reference that Cervelo somehow “secretly unveiled” a new bike to the press at Brain Bike the week after we were there is either true or false. If it is false, then the inference is (in my opinion) sloppy journalism that smacks of sensationalism. If it is true, well then, stop beating around the bush and bring it on! You guys know the ST rules: photos or it didn’t happen! My sense is that some cub reporter hopped up on Cervelo flavored Kool-Aid heard someone say the letters and numbers “4”, “C” and “P” in some order, saw some weird looking plastic shapes laying on benches (there were plenty of those laying around) and simply ran with it. The Cervelo Kool-Aid tastes pretty darn good, and it is easy to get a little loopy on it, but it’s important to keep both feet in the here and now. I have my ideas about where Cervelo may go with future designs, but they aren’t even worth discussing since they are simply guesses at this point.
The incessant rumors about a “P4C” aren’t good for Cervelo and Cervelo dealers. People considering the purchase of a current P3C may be compelled to wait for a product that, as yet, doesn’t exist officially.
Tom,
Thank you. Excellent point. This could apply to any product area. Indeed, we need/want innovation. However, I don’t think the general public realize the challenges that this places on the system, and in particularly the retailer, when there are big changes to models and lines every year. New is good, but too much new, can be a real problem. Remarkably and rightly many dealers applaud, companies that keep things fairly consistant from year to year.
IIRC Gerard denied on this forum working on a carbon version of the P3 a few months before releasing the P3C. So, I woudn’t hold my breath about getting any clue from Cervelo before the official release of a new bike, if there is such a thing!
gerard denied on this forum working on a carbon version of the P3 … before releasing the P3C. So, I woudn’t hold my breath about getting any clue from Cervelo before the official release of a new bike.
bingo.
I don’t understand why more companies, including Cervelo, are not creating frames and forks that allow the front brake to fit behind the fork. It seems a fairly simple thing to do as I know Oval makes a fork that allows for this. Getting the front brake out of the direct line of the wind would seem to smooth out air flow - as compared to hiding the rear brake like the Felt DA which seems rather pointless to me. I suppose I could always just buy a P3C and the Oval fork but it would be nice to not shell out more money for an after-market fork, especially when this seems something so basic.
“I don’t understand why more companies, including Cervelo, are not creating frames and forks that allow the front brake to fit behind the fork.”
I do, because there is no benefit. The supposition is that placing the front brake behind the fork somehow makes it more aerodynamic. That isn;t necessarily the case, even though it would seem to be intuitively.
Most of the systems we’re seeing now with a brake behind the fork don’t provide real drag savings. Some may actually be worse than a traditional front brake orientation from an aerodynamic perspective- I can’t comment specifically since I don’t have the data to post and I’m not an aerodynamic expert. I am relating several conversations I’ve had with aerodynamic experts and product managers from Felt and Cervelo specifically.
Now, there are some drag savings to be gained by *integrating *brakes into the fork itself. If the brake system were entirely concealed withing the fork producing a smooth leading and trailing edge then we could see some drag savings in this area. This means no brakes hangin outside the fork in the front or the rear. This is a tall order mechanically speakig as it would mandate introducing the entire brake inside the fork with cable routing- read- lots of holes in the fork blades- not so good for structural integrity.
Features without tangible benefits are of no real value beyond novelty, and that is some of what we are seeing in the repositioning of front brakes now.
I think it’s safe to say they and other companies have tested this and the results aren’t what you are assuming they will be.
The trailing edge of a tube is often more important than the leading edge. So while a brake in front of the fork may disturb the air, the fork smooths it back out allowing it to then hit the optimally shaped downtube cleanly. As opposed to clean air hitting the front of the fork which would then get disturbed coming off the back of it and then onto the downtube.
Actually, he denied that they were working on a carbon P3 because they had intended for it to be called the P4. He has stated that there apparently is a trademark issue with “P4”.
I’m not an aerodynamic expert
Nor, am I. However I do know that often what works is what does not “look” as aero as you think it is. I note that if you look head-on ( the view the wind sees the most of) at a certain bike that has the brake mounted behind the front fork, the forks at the crown/frame junction are nearly as wide as on an MTB bike, with as you pointed out Tom, a messy trailing edge created by the brake. My rudimentry knowledge of aerodynamics, would lead me to believe that this is not the best set up, even though from the side, this looks like a “great” set up.
“This is a tall order mechanically speakig as it would mandate introducing the entire brake inside the fork with cable routing- read- lots of holes in the fork blades- not so good for structural integrity.”
As you may be well aware, there are already prototypes out there that have mastered that technical task.
Real world reliability and servicability may be the only remaining issue.
And when I loked at those prototypes, they didn’t have “lots of holes” in the fork. They had exactly two: One for each brake-pad.
After all, forks nowadays are made out of CF and can be molded at will.
Didn’t you learn anything about CF at the “Brain-Bike”? 