Speed difference for a 40k between P2 and P3?

There wouldn't be a difference in time over 40k if the rider was averaging 25mph.

Not really an "unhelpful answer" because there are far too many factors involved.  The P2 is already a fairly well designed aerodynamic frame and the P3 is claimed to be slightly better.

But if you were to do something like set up your position differently between the two, it can make the P3 SLOWER than the P2.

There are too many variables to give you an answer.  Even Gerrard at Cervelo would be vague on that answer.

the same difference between the European and African swallow in it s annual migration...

-B

I am by no means an expert in this area but here is my understanding (as good or as bad as it might be).

If both the P2C and P3C were set up identically (geometry not components) the only advatage of the P3C would be a slight weight advantage and better bearings? ( someone with more knowlege can help provide details here if there are other things that would made a speed differance).

Really the advantage of the P3C over the P2C is the opportunity to get a more aggressive position on the bike and if this is utilized and the rider is capable of utilizing it then there would be some advantage but then the bikes would not be set up identically.

I do think that due to the small differances there would be a small differance in speed but to put a number on it I think would be nearly impossible in reality (in theory on paper it could be calculated I guess).

Michael

The P3 is lighter, it has different tube shapes, hugs the rear wheel differently, has a different ffront end and yes, it does promote an aggressive position.  Bearings have zero to do with the P3 unless you are talking about how someone built it up.  I feel the comparison the OP was looking for was straight up frames (assuming exact same componentry).

It is not really arguable that a properly set position on a P3 will provide the opportunity to be faster than the P2, but the rider must be able to hold the position and generate power in it.

Hell, even though they know every Joe and Jane out there with cash wants the P3 because of its cool-factor for Cancellara and other top pro cyclists and triathletes, the guys at Cervelo have said that the reality is that it is designed around someone who is able to make power in and maintain a very aggressive position.  That is probably only about 10-15% of the competitive triathletes out there.  The majority of P3 owners have their positions set up totally wrong for the frame and would have been better suited with the less aggressive P2.

BUT ...... it is their money and their ride, so they can do whatever the heck they want.

Hell, Chrissie Wellington rode her P2C to a Kona victory last year as well as many other wins this year.  That's gotta say something about the quality of the P2C frame ......... or the fact that the rider makes the bike, not the other way around.

Assuming two trials run under exactly the same conditions except for the change in bike - one on a stock P2, one on a stock P3:

The difference would be some function of this stuff (benefits of 2009 P3 over P2 from the Cervelo website)...

More aero seattube - The curved seattube covers more of the rearwheel than any other cutout, resulting in even better aerodynamics.

More aero seatstay/seattube transition - The seatstays blend into the main triangle without any aerodynamic disruption in the form of a monostay, thereby further improving the aerodynamics.

Lighter - The P3 is 150g lighter than the P2.

...plus the difference (if any) in performance of the components (Dura-Ace derailers vs Ultegra etc).

What kind of a time difference all that would equate to I have absolutely no idea.

Weight has zero bearing on aerodynamics, only on acceleration.  On a very hilly course, or something with a lot of technical turns that you have to accelerate out of, then yes, it has some minimal input in the overall time.

If I'm going about 25 mph on a P3C, or 25 miles on my skateboard, I'm going at about the same speed.  Mode of transportation is immaterial to the question as it is asked.

Maybe your post was kind of kidding.  I'm not sure.

It is obvious to me that what the OP is saying is "when riding a P2c or a P3c around 25mph speed.  What would the probably small difference be between the P2c and the P3c?  20 seconds?? More/less??"

Speed (I presume) was offered as a way of providing the educated folks with more information based on the possibility/likelihood that the overall total time savings is more at slow speeds due to being on the bike longer.  20 seconds faster would imply a speed faster then 20 seconds slower but still near 25mph.

Missing, of course, is the offering of how long on the bike is one suggesting the 20 seconds savings.

Follow-up question.

Where can I find information on "an aggressive position".  I want to understand more about what aggressive entails and how the body might be affected.

Wow super replies.  This forum is awsome.  I was at the Cervelo store last night and the owner told me that a P3 would give you a 2 minute advantage over a P2 for a 40k.  He then said that might not be accurate that he had to do the math in his head and was not really good at math.

 I just not think this was reasonable.  I thought it was an improvement in time because of the better aero of the P3.  But that is not it.  It is the aggressive position.  So for me with limited flex I would most likely be better of with a P2. 

 I was thinking that if everything else was equal and just buying a P3 over a P2 would improve me by 2 minutes I am buying the P3.  But sounds like this is not true.  I might even consider it for 20 second improvement.  But it sounds like that is not guranteed.

 Thanks for all the info.

I agree that we are all grasping at straws to come up with rational realistic answers since the OP is not that clear of the "real" question.  But here are a few more thougths/comments.

1.  The weight of the bike will make some difference (not aerodynamically) but in acceleration as well as the effort to keep it at speed.  However, as has already been said, The difference in weight between both bikes is little and would have little to do with the difference in time in reality.

2.  I recently went from a Trek 1200 (low end, aluminum, road bike) to a P2C (Ultegra).  I am averaging on multiple distance rides a full 2 mph faster average on each ride (18mph on my old bike to 20mph on the P2C).  My point is that the P2C is much faster than my old bike, but I wouldn't expect any difference in my times from a P2C to a P3C (and as has already been said, it could be slower).

3.  Aggressive position.  The headtube on the P3C is shorter than the P2C so that you can get a lower stance (handle bars lower) on the P3C (more aerodynamic).  However, the rider needs to be able to be able to ride in this position and still create power (as has been said before, only a small percentage of people could probably do this).  Sorry, I don't know where to look up this kind of information?

4.  I suppose these differences between the P2C and P3C (Aerodynamic drag coefficent, weight differance) could be used to calculate the differance in time between the two however what I think most poeple are getting at is that the assumptions you would have to use to calculate this in theory are probably not realistic in reality.

Michael

I did a lot of research before purchasing my P2C and quickly came to the conclusion that the P2 was probably a better value for me and also that the P3 is not really an "Upgrade" for future reference.

The P2 and the P3 share a great deal in terms of geometry and like others have said, the biggest difference is in the rear triangle and also the shorter stance of the frame.

Unlike a lot of other manufacturers, Cervelo does not "Dumb Down" their mid-range bikes. The Carbon in the P2 is the same as the P3 and the front triangle (although a bit taller) is basically the same. According to Cervelo, the primary reason for the price differences is the compexity of fabricating the rear triangle on the P3.

In the end, this is good and bad for Cervelo. The world is full of stories of folks like me who went to the P2 (or the P3) and experienced a substantial improvement in speed. All things being equal, from what I have read, been told and experienced for myself, the differences between the P2 and the P3 will not be much if anything at all. (So Cervelo will not be making much money selling the P3C to P2C owners)

I agree that the P3 almost demands the rider be limber enough to curve his/her body around the P3; but it is also possible to set up the P2 in the same agressive manner and so the agressive fit of the P3 is not significant. (As a difference from the P2) 

In general, the P2 does offer a wider range of fit options, and I would suggest that a good fit will trump a less than optimal fit for more aero any day. (Especially over long course events)

I know lots of folks who love their P3C and have done some great things with the bike; but I have also kown and experienced first hand what the P2C has to offer and it is definitely no second rate bike.

now that is funny.

Let me share my experience.  In April 08 I bought a new P2C Ultegra (20.88 LBS with standard wheels) and did the following 4 races in order with it

1st ever tri sprint race 10 miles @  23.37 MPH avg with standard wheels

1st Olympic race 40k @ 22.06 mph avg with zipp disc and 404 front

Sprint race 15 miles  @23.56 mph avg with zipp disc and 404 front

Sprint race 10 miles @ 26.20 mph avg with zipp disc and 404 front same course as 1st sprint ever. 2.8mph improvement?? was it the wheels or the training? i believe it was both!

Now 2 days ago I picked up my 2009 Cervelo P3 World Champion Limited Edition w/ SRAM RED(18.20 LBS with zipps). I also got a ZIPP Sub-9 with 1080 front (tubulars). Bike has been fitted and I have ridden it 60 miles or so with the Shimmano RS wheels. Yes the bike feels faster and seems to go faster at a lower heart rate. 

This weekend I am doing another Olympic race. I am planning on a pretty good bike split.  Will this give a you comparison. NOPE. But I will let you know what the time was.

Daremo - 2008-09-17 2:00 PM ... or the fact that the rider makes the bike, not the other way around.

The P2C is a great and fast bike. I bought the P3C because I enjoy the sport and plan on doing longer races next year, a couple HIM and a Full. The longer the time on the bike the more the aerodynamics payoff.

BTW my name is not Joe it is John. LOL

Think of people who sell bikes as if they were car salesmen. At least half the time I have found that people who work in bike shops know very little about anything and have weird biases. There are good shops, but none near me!

You could answer the initial question by measuring the drag between the 2 bikes and calculating an estimated time savings for 40K, but that would be theoretical and not  really a good way to shop for a bike.

You could answer the initial question by measuring the drag between the 2 bikes and calculating an estimated time savings for 40K, but that would be theoretical and not  really a good way to shop for a bike.

Laden or Unladen??

ksmith4 - 2008-09-17 10:06 PM

cxk9758 - 2008-09-17 1:46 PM P3 might be lighter because u will have a lot less money in your wallet.

now that is funny.

Let me share my experience.  In April 08 I bought a new P2C Ultegra (20.88 LBS with standard wheels) and did the following 4 races in order with it

1st ever tri sprint race 10 miles @  23.37 MPH avg with standard wheels

1st Olympic race 40k @ 22.06 mph avg with zipp disc and 404 front

Sprint race 15 miles  @23.56 mph avg with zipp disc and 404 front

Sprint race 10 miles @ 26.20 mph avg with zipp disc and 404 front same course as 1st sprint ever. 2.8mph improvement?? was it the wheels or the training? i believe it was both!

Now 2 days ago I picked up my 2009 Cervelo P3 World Champion Limited Edition w/ SRAM RED(18.20 LBS with zipps). I also got a ZIPP Sub-9 with 1080 front (tubulars). Bike has been fitted and I have ridden it 60 miles or so with the Shimmano RS wheels. Yes the bike feels faster and seems to go faster at a lower heart rate. 

This weekend I am doing another Olympic race. I am planning on a pretty good bike split.  Will this give a you comparison. NOPE. But I will let you know what the time was.

Daremo - 2008-09-17 2:00 PM ... or the fact that the rider makes the bike, not the other way around.

you are 100% correct

The P2C is a great and fast bike. I bought the P3C because I enjoy the sport and plan on doing longer races next year, a couple HIM and a Full. The longer the time on the bike the more the aerodynamics payoff.

BTW my name is not Joe it is John. LOL

Wanna adopt me?  Throwing that kind of cash around...I'll just wait for your equipment leftovers.  :P

Good luck this weekend.

So this is not a total hijack,  I don't think there is a huge difference between the two bikes if set up the same.  Definetly not 2 min over a 40K. 

If you went exactly 25 mph on the P2 you'd do the 40K in 59m 17s.  With a 2 min advantage for the P3, you would avg 25.9 mph.  Almost 1 mph because of the frame only...NO WAY.  Again, same course, conditions, etc.

for me the difference is how well i show off my freain' awesome bike!! the confidence of the P3C would burn me out on the bike hahaha......but i might have some crappier (less) aerodynamic clothing on because i spent all my money on the P3......hahah

but seriously i would say your body is more important then the bike...maybe 5 seconds, some ooh's, ahh's, and "whoa" that kids in debt!!