A little P4 love: Head-to-head TT vs P3SL w pics!

Oct 22, 10 14:12

Post #1 of 54 (14504 views)

So after a few false starts, several parts issues, and many frustrating hours of building, my new P4 is complete!

I got a deal at the IMLP expo this year so decided to use some of my savings towards a paint job and had the hideous "P4" logo on the downtube replaced with the original Cervelo logo.

I built it up with SRAM red (Force FD as to avoid pulling a schleck), TT500 brake levers and TT900 shifters. Aerobars are Brezza II, Specialized toupe saddle.

Zipp 808s with disc cover, SRM FSA k-force light cranks and garmin 500 are all swapped between my other bikes.

I also had a friend make me a custom behind the seat bottle bracket for a single bottle. I had a similar setup with my P3SL using zip ties only, but I couldn't get this to work properly with the P4 seatpost.

I decided to do a head-to-head road test with my P3SL which is also a 58cm frame with identical geometry. Because of the differences between the Brezza and Vision bars, the P4 pads actually sit 0.5cm higher but 1.5cm more forward. Otherwise both bikes are setup identically.

The Test:

I did this over 2 different days. I mapped out a 10k loop with rolling hills in an area with little traffic. I did back-to-back runs at an average of 285 watts, and between runs I swapped wheels, cranks and garmin from one bike to the other and rezeroed the SRM.

The Results:

Day 1 - moderately windy, similar for each run
1st run - P4: 15:37, ave power 284W, ave HR 175
2nd run - P3SL: 15:54, ave power 285W, ave HR 174
P4 savings 17s

Day 2 - Very windy, significant crosswinds, maybe a bit worse for the second run
1st run - P3SL: 16:00, ave power 284, ave HR 175
2nd run - P4: 15:45, ave Power 285, ave HR 174
P4 savings 15s

Discuss.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 14:18

Post #2 of 54 (14478 views)

45sec to 60 seconds over a p3c so sounds right about in that range. I don't recall the p3c being that much faster then the p3sl.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 14:18

Post #3 of 54 (14476 views)

1 minute per 40k!

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 14:18

Post #4 of 54 (14476 views)

Good looking bike....: )

-------------------------------
I'm faster in Kilometers!
Wattie Ink Triathlon Team
Powered by Accelerate 3

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 14:24

Post #5 of 54 (14447 views)

had the P4 been under my wife instead of the P3SL she would have now be the Mopac TT women's record holder instead of 2 seconds short of it.

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 14:30

Post #6 of 54 (14424 views)

Very nice Larbot. Thanks for posting this. Any chance you also have avg. speed as well as max + min W for the two days?

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 14:30

Post #7 of 54 (14422 views)

One thing I've learned from doing similar things is that you can't really tell the strength of the wind by feel. In any case, very interesting. Now, do it another twenty times and you'll have a sample size that confirms or refutes your n=2 experiment. I've gone out to test new stuff and been very dissappointed with the results, but if I stuck with it for enough repetitions then most of the time I find that my hypothesis are correct.
Chad
P.S. I've seen a few P4s on eBay of late, which means they have been out long enough for buyers remorse to kick in. By the time my wife or I have a job I suspect they will have dropped into a range I can afford used. Of course, it may not be buyers remorse so much as Triathlon Remorse which I define as 1) a condition under which a person realizes that training for triathlon is diffficult and they go back to spending an hour at the gym to do 15 minutes of working out rather than be reminded they can only buy so much speed.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [cdw] [ In reply to ]

Oct 22, 10 14:33

Post #8 of 54 (14394 views)

In Reply To:

15 minutes of working out

15 minutes? IN A ROW?

=)

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [cdw] [ In reply to ]

Oct 22, 10 14:42

Post #9 of 54 (14359 views)

Yeah ideally I would do a bunch more runs, but it's a pain in the ass to drive out with 2 bikes and swap shit around.

If both runs didn't agree so well with each other I might consider doing more, but right now I'm comfortable believing the P4 saves me somewhere between 1-2s per km.

Anyway to be sure at this point? Nope.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

LuckyMe

Oct 22, 10 14:42

Post #10 of 54 (14354 views)

That P4 looks reeeaallly nice with the red accents on the wheels!

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 14:46

Post #11 of 54 (14334 views)

I'm surprised nobody said anything about that round bottle on the P3SL downtube! Where is the world going!

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [cdw] [ In reply to ]

Oct 22, 10 14:49

Post #12 of 54 (14317 views)

In Reply To:

Now, do it another twenty times and you'll have a sample size that confirms or refutes your n=2 experiment.

Yeah I agree, if the OP could provide a larger sample size I would be happy to run the statistics for them. :) Would be interesting to see if the difference between the two is statistically significant at all or just due to random chance.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 14:52

Post #13 of 54 (14291 views)

If you ever want to dump the P3sl frame/fork/headset/seatmast just let me know.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 14:54

Post #14 of 54 (14283 views)

The only thing I'm TRULY concerned with is the fact that you're leaning the P4 against a metal signpost!! I know it's aero, but what if a gust of wind pushes it and causes a scratch?! Heresy!

Gorgeous build. I am really into the 2011 P4 although the 2011 P3 looks great too...

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 16:19

Post #15 of 54 (14135 views)

It's crazy to think we pay thousands of dollars on new sleek carbon frames for 15 seconds. But I am just as guilty!

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 16:50

Post #16 of 54 (14072 views)

Personally, i love that P3. And with that wheel configuration, dang that is sweet.

Gotta find me a used frame set this winter and a used 9spd drive train.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [draketriathlon] [ In reply to ]

Oct 22, 10 17:01

Post #17 of 54 (14045 views)

"45sec to 60 seconds over a p3c so sounds right about in that range. I don't recall the p3c being that much faster then the p3sl. "

Isn't that what was "promised" in terms of improvements from P3 alum to P3 Carbon? If I recall correctly the P2C was an aero improvement of P3 alum as the carbon allows to be more flexible in terms of working with the shape vs. the traditional welding method of building frames. Not that marketing should be any different as it is the job of the marketing dept. to sell product, I'd just be interested to see if data was ever published that compares their frames from P2,P3,P2C,P3C, P4, tested same day on same testing equipment with several runs and same protocol. If we were to add up the "promised" aero/time savings of the various frames, e.g. savings from P2 to P3, then from P3 to P2C, from P2C to P3C, then the time savings from P3C to P4...something tells me we'd have a much faster "hypothetical" frame than what the P4 is as every time the time improvements are stretched by the power of marketing.

When they kick at your front door, How you gonna come?
With your hands on your head
Or on the trigger of your gun
Paul Simonon

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [qqqq] [ In reply to ]

Oct 22, 10 17:22

Post #18 of 54 (13988 views)

Cervelo has released data comparing all of their carbon frames. It has been posted here many times, and more or less agrees with the results this guy got.

Gerard has hinted that the P3SL is very similar in drag to the P2 Carbon. With the extra rear wheel fairing more or less exactly making up for the lack of a shaped head tube and other refinements that carbon allows.

Nothing in Cervelo's marketing claims has ever failed to agree with reality as measured by field testers and independent wind tunnel tests to my knowledge.

This guys field test would imply an entire minute saved over 40k. That is a LOT of time. Especially since you are comparing it to a frame comparable to a P2C. There are many pros in the tour de france on slower frames than *that*

It would suck to be on a frame that wasn't developed in a wind tunnel and go up against a P4, Shiv, Trek, or Felt.

You could be giving up 2 mintues!

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [jackmott] [ In reply to ]

Oct 22, 10 17:36

Post #19 of 54 (13965 views)

the bars and the downtube bottle alone could account for ~1-2 seconds per Km. I am not convinced that the P4 is all that much faster than the P3SL.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [bpq] [ In reply to ]

Oct 22, 10 17:38

Post #20 of 54 (13954 views)

one would think but

1. gerard and cobb have both hinted that round bottles add a surprisingly low amount of drag when mounted ont he downtube

2. the p4 HAS A BOTTLE TOO, so the comparison is rather fair, at least for athletes who wanted to carry more than 1 bottle, or who can not carry one between their forearms.

the difference would no doubt be reduced some if you primarily used your bike with no bottle on the downtube, or used an aero bottle, but I bet there is still 40-50 seconds of time saved per 40k

In Reply To:

the bars and the downtube bottle alone could account for ~1-2 seconds per Km. I am not convinced that the P4 is all that much faster than the P3SL.

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [jackmott] [ In reply to ]

Oct 22, 10 17:42

Post #21 of 54 (13947 views)

I'd take that bet...

swap the 3T bars over to the P3SL, put the down tube bottle between the aero bars and re-run the tests. I am guessing there's less than .5 sec/KM difference.

That's still 90 seconds over an Ironman... but you can buy a lot of swim lessons and running shoes for the cost of a P4.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [bpq] [ In reply to ]

Oct 22, 10 17:58

Post #22 of 54 (13908 views)

$500?
what would you accept as proof? a tom A or andrew coggan field test?

wind tunnel data? =)

The P3SL is a sweet bike, it is what I own. But that head tube is *round* and that rear brake is exPOSED

and the downtube isn't tucked up against the tire.

In Reply To:

I'd take that bet...

swap the 3T bars over to the P3SL, put the down tube bottle between the aero bars and re-run the tests. I am guessing there's less than .5 sec/KM difference.

That's still 90 seconds over an Ironman... but you can buy a lot of swim lessons and running shoes for the cost of a P4.

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [jackmott] [ In reply to ]

Oct 22, 10 18:08

Post #23 of 54 (13886 views)

:)

a Tom A or AC field test would definitely cut it... and I would love to wager a $500 donation to your favorite charity, but my wife would have both my legs broken for throwing away money, so a gentlemans bet will have to suffice.

It's not that I don't think the P4 is a fast bike, that's well established, it's that I think the P3SL is also a very well designed bike and the OP ran tests that didn't set it up optimally.

I would stand by my guess that the difference between the two (with the same bars and sans bottle) is under a second per Km.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [bpq] [ In reply to ]

Oct 22, 10 18:13

Post #24 of 54 (13872 views)

In Reply To:

I would stand by my guess that the difference between the two (with the same bars and sans bottle) is under a second per Km.

maybe in size 48 it is!

sadly I have to ride a 58

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [jackmott] [ In reply to ]

AustinTriCyclst

Oct 22, 10 18:15

Post #25 of 54 (13863 views)

MDR's new P4 came in today!

http://www.austinTRIcyclist.com
http://www.Cannondale.com

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [AustinTriCyclst] [ In reply to ]

Oct 22, 10 18:16

Post #26 of 54 (8776 views)

In Reply To:

MDR's new P4 came in today!

does "MDR" have an old one he no longer needs?

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [bpq] [ In reply to ]

Oct 22, 10 18:21

Post #27 of 54 (8774 views)

Agree with bpq. the 3T bars and bottle make up over half of the difference.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [applenutt] [ In reply to ]

Oct 22, 10 18:23

Post #28 of 54 (8771 views)

3T brezza bars could be *less* aero than vision bars. brezza are the UCI legal bars.

for the lose

In Reply To:

Agree with bpq. the 3T bars and bottle make up over half of the difference.

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Last edited by: jackmott: Oct 22, 10 19:00

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [bpq] [ In reply to ]

Oct 22, 10 18:26

Post #29 of 54 (8767 views)

I think a round bottle versus P4 bottle is a fair comparison as that's how they're generally rode. I've always ridden my P3 with a round bottle.

As for the bars, yes the brezzas are probably faster than the vision, but I'm sure not going swap bars and recable the bike to compare. Either way, I doubt the difference from bars is on the order of 1s/km, I would take JackMott's side of this wager. Maybe with the ventus bars?

That being said, I was expecting the difference between bikes to be a bit more based on wind tunnel data. Somewhere around 2-3s/km.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 18:29

Post #30 of 54 (8764 views)

Gorgeous setup.

Is your friend available to make me one of those brackets? :) It's superb. Perhaps a double version a la Chris Lieto?

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [jackmott] [ In reply to ]

AustinTriCyclst

Oct 22, 10 19:21

Post #31 of 54 (8706 views)

Missy will keep her 48cm P3 as a trainer bike.

http://www.austinTRIcyclist.com
http://www.Cannondale.com

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [cdw] [ In reply to ]

psycholist

Oct 22, 10 19:21

Post #32 of 54 (8706 views)

I've seen a few P4s on eBay of late, which means they have been out long enough for buyers remorse to kick in. By the time my wife or I have a job I suspect they will have dropped into a range I can afford used. Of course, it may not be buyers remorse so much as Triathlon Remorse which I define as 1) a condition under which a person realizes that training for triathlon is diffficult and they go back to spending an hour at the gym to do 15 minutes of working out rather than be reminded they can only buy so much speed.

Maybe not so much "buyer's remorse" as what I'll call "mechanic's remorse." The P4 is a BITCH to work on for most folks. Not to disparage dentists, but I know a number of them who buy REALLY nice equipment and have no time to train on it or work on it. The first time things go out of adjustment or wear out, if it's not a simple fix, it's time to sell it. With the P4, even the guys at the LBS probably had a hard time getting things just right with the internal cable routing and/or the rear brake. Mr. Dentist didn't have time to fuss with it, so he threw up his hands, put it up for sale and bought a Speed Concept which he'll ride until something starts to rub or creak or click or ...

I've learned many of my 2009 P4's little quirks. She's a tempermental thing to work on. But she's oh so sweet to ride! When I dress her up with her race wheels and aero bottle, she whispers in my ear that I need to hang on 'cuz I'm in for an amazing ride.

.

Bob C.

The "science" on any matter can never be settled until every possible variable is taken into account.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [AustinTriCyclst] [ In reply to ]

Oct 22, 10 19:28

Post #33 of 54 (8687 views)

In Reply To:

Missy will keep her 48cm P3 as a trainer bike.

MDR and KH need to form their own bike racing team and go straight to category 1

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [psycholist] [ In reply to ]

Oct 22, 10 19:33

Post #34 of 54 (8679 views)

But she's oh so sweet to ride! When I dress her up with her race wheels and aero bottle, she whispers in my ear that I need to hang on 'cuz I'm in for an amazing ride.

Awesome. But very good to know. I'm never going to sell the Yaqui, but I figure I'm giving up a good chunk of time to the P2/3/4 crowd and have wondered if I would go all the way to the P4 when looking for a new bike. When I saw several in the $2500 range, for a frame, I was encouraged. I'll just spend enough time tweaking it until it matches the Yaqui characteristics and then it will be a race-day only bike. Alas, in the mean time I have plenty of work bringing the ftp closer to 300 watts than 200.

Chad

P.S. I'm not really that worried about the rear brake anyway. I spent the winter swapping out front end combos and got tired of redoing the front D and rear brake, so I eventually just stopped. I missed the front D on occasion, but never the rear brake.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 19:36

Post #35 of 54 (8671 views)

Cool study and SWEET bike!

Chris Thornham
Co-Founder And Previous Owner Of FLO Cycling

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [jackmott] [ In reply to ]

AustinTriCyclst

Oct 22, 10 19:44

Post #36 of 54 (8652 views)

At least we both know where the true talent in our respective families lie.

http://www.austinTRIcyclist.com
http://www.Cannondale.com

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 19:44

Post #37 of 54 (8652 views)

I would be very surprised if the 3T bars are any advantage over the Vision. People discount the Vision bars because they are old and aluminum, but the test I saw showed they were still a match for newer carbon bars.
When I was testing separate front ends I swapped out stuff and just unplugged one brake lever and one shift lever in the "new" set up and could do it in about 10 minutes or less. As such, I did upwards of 15-20 runs each when I was testing the Superman position vs. the Obree Egg, until I was pretty confident of my results. I even threw in a few regular FIST position runs with no basebar for comparison, just to remind me why I was doing it. In the end, it's a great use for a power meter when you are curious if something really matters. I was often surprised at stuff that didn't matter at all, like putting a bottle on the seat tube vs. no bottle. Could not measure a difference (Caveat--the bike does not have an aero seat tube or wheel cutout). Adding five pounds of dead weight. Also no difference.

Chad

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [AustinTriCyclst] [ In reply to ]

Oct 22, 10 19:52

Post #38 of 54 (8647 views)

It is pretty easy math in mine

In Reply To:

At least we both know where the true talent in our respective families lie.

Kat Hunter reports on the San Dimas Stage Race from inside the GC winning team
Aeroweenie.com -Compendium of Aero Data and Knowledge
Freelance sports & outdoors writer Kathryn Hunter

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 22, 10 20:04

Post #39 of 54 (8623 views)

Take that sign post out of your yard.
Cut your grass.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [psycholist] [ In reply to ]

Oct 22, 10 20:32

Post #40 of 54 (8601 views)

""mechanic's remorse...... Not to disparage dentists, but I know a number of them who buy REALLY nice equipment and have no time to train on it or work on it."

LOL!! Aren't dentists the same folks who buy two year old Porsches and can't believe they lost money on the cars two years later. All because they read somewhere that "old Porsches are classics".

At least that describes the dentists I know! :-)

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [cdw] [ In reply to ]

Oct 23, 10 5:26

Post #41 of 54 (8504 views)

actually... I thought the 3T bars were the Ventus. Given that they are the Brezza, you're right, they are probably not all that much faster than the Visions.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 23, 10 12:50

Post #42 of 54 (8376 views)

This thread is actually timely for me. I currently ride a P3SL, and have been considering upgrading to a new bike.

I guess I've been a bit dazzled by all the new stuff that has come on the market.

My P3SL is basically stock. I love this bike, which is why I've been going back/forth on this decision for the past 2 years.

Am I correct that the consensus is I may be better off upgrading some of my componants (cockpit, wheels, etc.) rather than dropping another $3500 on a new ride?

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Crafty] [ In reply to ]

Oct 23, 10 12:56

Post #43 of 54 (8370 views)

I think it depends on what you're riding with right now. It's a better bang for your buck to optimize other things first.

-Bike Fit / Position
-Aero Helmet
-Well Fitting Race Kit
-Aero Wheels with good tires pumped to correct pressure
-Bottle placement, and other "extras" on your bike

Once you've maxed these things out, a new bike might be the next step.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Oct 23, 10 15:02

Post #44 of 54 (8294 views)

beautiful! Love it!

David
* Ironman for Life! (Blog) * IM Everyday Hero Video * Daggett Shuler Law *
Disclaimer: I have personal and professional relationships with many athletes, vendors, and organizations in the triathlon world.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Apr 26, 11 7:27

Post #45 of 54 (7861 views)

Larbot, realize I'm not timely, but nice pics, beautiful bike, and good thread. Can you answer two follow-up questions:

1) What Zipp disk are you using that works with the P3 and P4?

2) Do you still like the P4 so much as compared to the P3 and other bikes?

Thanks!!

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [goodacre] [ In reply to ]

Apr 26, 11 8:22

Post #46 of 54 (7731 views)

He has an 808 with a wheel cover on it in the pics.

A zipp 900 clincher disc works fine for a P4. Not sure which tubular.

ishi no ue ni san nen | Perseverance will win in the end. | Blog | @nebmot | Strava | Instagram |

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Apr 26, 11 8:43

Post #47 of 54 (7650 views)

A bit of a sideways hijack....

Anyone have any idea what putting a front mounted aerobottle on an aluminum P3 does for its aerodynamics?

Seems like common Slowtwtich lore that an aluminum P3 is equivalent to a carbon P2 due to the P2's head tube shape. So, what happens to each when a Profile Design aerobottle or similar is placed in front of the head tubes?

Thanks

David K

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Apr 26, 11 8:59

Post #48 of 54 (7567 views)

What is the weight difference between the two bikes?

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [DavidK] [ In reply to ]

Apr 26, 11 9:00

Post #49 of 54 (7564 views)

ditto...

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [goodacre] [ In reply to ]

Apr 26, 11 9:05

Post #50 of 54 (7538 views)

Hiya,

Yes it's an 808 tubular with disc cover.

In general I love my P4 as compared to the P3. I find it super comfortable and very stiff/responsive.
Part of that may be the frame itself, part may be due to the Brezza bars vs Vision although I wish the Brezzas sat a bit lower and were more adjustable.
The SRAM groupo also shifts MUCH nicer than my dura ace on the P3.

The P4 bottle I don't have an issue with. I have gorilla arms so I can reach it without trouble.
As some others have said, it does take a little practice to replace properly.

Back brakes are pretty shitty and VERY difficult to install with having the crank rub the cable.
We'll see how the new brakes offered compare.

I've had no issues with the seatpost.

All that said I still do most of my training on my P3 and soloist and save the P4 for racing.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Cyronman] [ In reply to ]

Apr 26, 11 9:08

Post #51 of 54 (3750 views)

The P4 spec'd as is weighs 1.5 lbs less than the P3SL.
Sorry can't tell you how much of that is frame vs components.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Apr 26, 11 9:10

Post #52 of 54 (3746 views)

No problem just curious.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [Larbot] [ In reply to ]

Apr 26, 11 9:31

Post #53 of 54 (3712 views)

I don't know if it was luck or what, but the first time I put the new P4 brakes on it didn't rub, it took me four tries with the original brake.

Re: A little P4 love: Head-to-head TT vs P3SL w pics! [cdw] [ In reply to ]

Apr 26, 11 9:40

Post #54 of 54 (3698 views)

cdw wrote:

I would be very surprised if the 3T bars are any advantage over the Vision. People discount the Vision bars because they are old and aluminum, but the test I saw showed they were still a match for newer carbon bars.
When I was testing separate front ends I swapped out stuff and just unplugged one brake lever and one shift lever in the "new" set up and could do it in about 10 minutes or less. As such, I did upwards of 15-20 runs each when I was testing the Superman position vs. the Obree Egg, until I was pretty confident of my results. I even threw in a few regular FIST position runs with no basebar for comparison, just to remind me why I was doing it. In the end, it's a great use for a power meter when you are curious if something really matters. I was often surprised at stuff that didn't matter at all, like putting a bottle on the seat tube vs. no bottle. Could not measure a difference (Caveat--the bike does not have an aero seat tube or wheel cutout). Adding five pounds of dead weight. Also no difference.

Chad

Not that I doubt those results, but wondering if you recall where you saw the data? Was it published or private info?

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