OK, so picture on posts #37 and #375 is very near to reality :-)

Better picture of the "bottle" part :-) ?

Aero bottle is specific shape for P5 Disc.

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Professional French Bike Shop.
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The monostem looks actually really slim. Especially once you compare it with the monostem of the Shiv.
As far as I know the bars can be tilted by 15° for non UCI races.

...because you *know* the P5disc is slower, or you *think* it is slower? ;-)

ie, have you seen numbers? (know people who did a direct comparison?)

Betting against Cervelo in aerodynamics seldom (never?) works out well for people. Just about everyone was wrong about the P5X.

do you *know* who you're talking to?

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Eric Reid AeroFit | Instagram Portfolio
Aerodynamic Retul Bike Fitting

“You are experiencing the criminal coverup of a foreign backed fascist hostile takeover of a mafia shakedown of an authoritarian religious slow motion coup. Persuade people to vote for Democracy.”

Yep...I was expecting/hoping that some-one so meticulous in their preparation (and I respect very, very highly) would have some definitive answers.

Possibly the first guy in this thread who will lose to someone on this bike. :) Given that TD is apparently already training on it.

edit: that said MTM was clearly just making a lighthearted humorous comment about disc brakes in general.

As well as Soren Kragh Andersen.... from Martin pictures :-)

I guess some (most ?) of us are convinced (from Spe data for exemple) that disk are not, at this point in time, an aero gain vs the most efficient rim brakes systems.
The advantages of disk brakes are in other areas...

And if Specialized worked a lot on the rest of the bike (2019 Shiv) to compensate (fork, "water tank big tail", ...) it does not appear from the pictures Cervelo made a lot. But we might be wrong.

Maybe with the appropriate adds-on the P5D will equal or beat the P5R (and the P5X) ?

No, I haven't seen any numbers, the comment was mostly tongue-in-cheek. As I see it, a state of the art rim setup will currently beat a state or the art disc setup in aerodynamics from the data I have seen so far (and generally eye-balling the differences generally agrees with this). The gap is not huge (and I would think that the P5D would probably be pretty close to the P5R) and a generation or two (or maybe three) down the line it will probably be a wash (or maybe come out ahead if rim setups stay at status quo) - right now limited wheels choices, crudely designed (in aerodynamic terms) calipers and levers, etc. are hampering aerodynamics if you really want to save every last watt.

I am guessing we are unlikely to see a new Rim brake Cervelo TT bike in the future, which is kind of sad. I suppose there will be few new rim brake bikes moving forward, which is reflected in most of the new aeroroad bike being disk only.

Are they going to make substantial changes. Seems like the first version had some bugs that needed to be worked out.

I think there might be a difference but don’t think it’s too much of it.

Check below article on wind tunnel testing of rim break vs disc break and results aren’t that different.

https://www.parcours.cc/...at-disc-brake-debate

First test showed the following;

“The results showed that the difference between a rim brake model and a disc brake model were less than 1W, using the most common 160mm rotor diameter. As you might expect, reducing the rotor size to 140mm narrowed the gap to 0.3W.”

Said that, I think the P5D could be as good as the P5Six in terms of aerodynamics and speed.

Just my opinion.

Looking at the test you reference :

Result is probably a 10 gram difference, out of less than 200 gram. So more than 5% difference.

So rotor drag might be less than 1w
But this is for one wheel, not two.

And this does not take into account the calipers, which is probably the worst part (as mentionned by Martin) of the additional drag induced by disk brakes.

In short, delta for a complete bike might be very different than "1w"

Don't! get me wrong. I love disk brakes. But let's wait for other results (than the Specialized Shiv) to see how disk bikes compare to :
1) high end bikes (P5 Rim, ...) : probably not that good ?
2) mid range bikes (P3 with Ultegra) : may be better ?

This jives with intuition. On itegrated rim brake bikes, only the brake pad is in the wind. On a disc brake bike it's the disk, a thick hub flange, a blocky caliper, and extra spokes. I don't see how they could get around that. Even if/when calipers and rotors become aero shaped. Maybe if they split the left fork leg with a slot for the rotor and the caliper being completely behind the fork with shrouding.

https://tutriatlon.com/...sc-dura-ace-di2.html

😂

May be they could hide the caliper behind the fork and seat tube, and brake directly on the side of the rim (a large disk, so very efficient, and aerodynamically integrated). We could call that "optimized disk brakes" or "rim brakes" ?

That is my preferred solution as well

Must be a drag when you can’t make a joke without your every word being analysed! :-)

Sorry about that and thanks for your thoughts.

February 11 2019

Tic tac tic tac .....

Et pendant ce temps la, au siège du marketing Cervelo .... (french private joke)

no, not really.

Seen this morning that Sunweb are also at Volta ao Algarve which has an ITT on stage 3 on 22nd Feb (UAE TTT is 24th with Dumoulin). So if we're going to see it properly soon I guess it's going to be next week!

Or maybe we’ll see it tomorrow! Tour de la Provence starts with a TT tomorrow!

https://www.instagram.com/...igshid=1m52uudr5nip8

Indeed, Sunweb are using the new P5D on the Tour of Provence. Just saw it on TV.

Here it is, on french TV, during the prologue.

Asbjorn Kragh Andersen, so probably the bike shown by Martin in a velodrome recently.

Bad quality picture.... sorry (I'm possibly paid by Cervelo :-)