I think the decisions are mostly based on looks. I like the look of the Cervelo beam bikes, and that is what I would buy if I were purchasing right now.

I think they are generally equivalent in aero, configurability, and breakdown for transport.

Bc it's a marketing gimmick...

They haven't really made any aero differences in the past 5yrs. Weight is negligible. Isn't the P5X also like $4k more? Storage may be a bit better, but that's the only real advantage I see

pretty much everything about this post is incorrect.

except for this "Storage may be a bit better"

I think its basically down to user preference and price. While the P5x/P3x/Px are all slightly heavier than the P5d, at the end of the day the performance gains you will see are pretty close and aero-wise/weight it seems to be a pretty close battle. I think if you take 2 riders on the 2 bikes at the same physiological metrics, it would be hard to differentiate error in the results from actual hard time differences based on the bike itself, assuming you fit both.

IMO I have to admit the capacity to carry stuff on the P5x (and Px series) is much more than any other bike I have seen, and the internal bladder option adds more options than the P5d would. If you are doing more climbing, I could see why the P5d is a better option. Otherwise, the longer you go, the more the P5x/Px series seems to provide more solutions.

Note that you can carry 2 bottles in the back, one on the down-tube and one BTA as well as the Shiv bladder in the P5x/Px series, with a total of basically 750ml x 4 (or slightly more with a larger BTA option) + 20oz (600ml) in the bladder. Not sure who would need all that volume in a race but the options are there and you can optimize it how you please. Works well in training and you can do what you please on race day. The P5d has the 2 out back, down tube and BTA, although note that the downtube is an aero bottle, but I hear it is a PITA to actually use. Might also worth considering how you want to run bottles and how you like to swap bottles at aid stations. Also note that the P5x/Px series has more storage options if you need (flat kit plus remove-able box) as well as a better cockpit setup (more adjust-ability and I also hear it's more stiff). It's also a beam bike. ¯\_(ツ)_/¯. Note that you can fit even more into the frame of the P5x, so for me I plan to put my flat kit in the small box (its small) and stuffing some spare tubes in the frame. If you like tubular, I think you could easily fit your spare in the frame.

I got my P5x at a steep discount this year. I have yet to actually ride it outside but I have been doing a ton of trainer rides and it is a noticeable improvement in comfort for me. I have the bladder setup with Yann's awesome storage solution and the bike as a whole is a huge improvement over my old Speed Concept all around. Packing, ease of adjusting and everything together outside of aero alone is a massive improvement worth the cost to upgrade, which all things considered was not a huge amount. Also my bike came with the travel box, worth considering as well.

Note that working on the front end really makes you appreciate the design improvements on the Cervelo over other options. If you just take it to your bike shop you may not appreciate how easy the bike is to work on. Can't comment on the P5d but I assume the adjust-ability is just as simple and stress free.

Not that theres any races to use this bike for this year, but I think if you had the option of both bikes, price not factored in, its down to sex factor (what you think looks good) and your personal needs. If you need more space, the P5x/Px series has the P5d beat. If you are a weight weenie, P5d for sure. I think anyone actually buying one over the other to see tangible improvements are more concerned about making a living now that racing is tits up and already own both bikes, because they are sponsored, and have wind tunnel data on both bikes anyways to make the decision easy.

Can you be more specific in your comparison to the Speed Concept?

The P5D is more aero and if I remember correctly it’s 3 pounds lighter than the PX. That said, the aero benefits can be negated if you have a bunch of fuel added to the bike but if you have simple and clean nutrition it’s faster. As far are cost, they are the same price technically but P5D is offered in an ultegra version which gives it a cheaper starting price.

Plus many, including myself, find beam bikes ugly and I personally would never ride one outside a race but have no issues training with my P5.

Because the PX is marketing to a market that is super niche / barely exists

1) Let's say it's marketing to the the crowd of triathletes who have gels taped to top tube. Your audience is people who spend 10k plus on bikes, who care about being aero, but not enough to optimize your cargo load, (who want storage to be aero, but not enough to wan an integrated BTA), and who are willing to buy a non-conventional bike...

2) Let's say it's improved comfort. How many athletes spend 10k on bikes, don't care about looks, and prefer comfort over raw speed?

3) Adjustability:..... Now what's the overlap of triathletes who know the importance of front end adjustability, but who also tape gels to top tubes, and don't care that their bike is 3 lbs heavier? And how many bike shops actually care about selling a tri-bike with an adjustable front end?

The PX series is an engineer's toy in search of an audience. People who are knowledgeable about tri-bikes and aero, will probably get a P5D and make sure they are carrying in an optimal way. People who tape tubes to the top, who also spend 10k plus on bikes will probably just ask the bike shop for recommendation, and buy whatever ryf, rinny, seb, jan is riding.Anne Hauge won Kona on a Cervelo! Sure I'll take that one! I like big Ben, what does he ride (P5x at Kona!, but P5D almost all the other races?!)

It's one of the downfalls of Andean (targetting all out aero crowd with a horrible front end), one of the downfalls of ventum (integrated hydration, and decidedly non-integrated looking front end)

It's the equivalent of going to a burger bar, asking people what they want if they ever order a salad. Launch said salad, and wondering why no one buys it.

Sure.

Breaking down the entire bike to fit into the box is amazing. TBH I dont really fly with the bike and I am not sure if I will any time soon but heres a few reasons.

The base bar on the P5x (Px series as well, not P3x though) splits into 2, all you need to do is loosen 4 screws which are easily accessable. Speedconept had a single base bar system and you needed to take off the aerobar/stem setup to access the base bar, which was a bit tricky to do. The brakes were also impacted with the removal. Not anything major, but it was something to handle, would be easy with 3 hands. The front brake also had some issues with sticking and cabling right, I had the low far setup so it was very aero, but the cables had some tight turns which were not easily managed.

You can take off the aerobar/pad setup with 1 screw and you can disconnect the junction A without anything else. Speed concept I hid the A box in the extensions (had plug in) but you had to fish wires a bit. Also the stem is a nightmare on the low far. The plastic housing on the stem cover is so tight I basically had to break the plastic to fit it on. I hear they improved the design on the newer SC and its only like 10-20$ but its a pita to put back on. I also added titanium bolts because the tiny ass bolts sucked.

The fork can come off if you so desired with a more conventional fork insertion and you have direct access with a removal of the cover. The only hard thing would be flipping the base bars, which requires a hydro unplug. Not impossible, but its the hardest job you got on the bike. The SC you have to remove everything on the front end to access the fork, and the fork also impacted the plastic stem (above) and brake/wires, so it was a chore to take everything off if you wanted to access the fork/bolt system. Note that when you removed it, you also may move the rear brake cable slightly, which was also kind of a PITA to make just right.

If you wanted to adjust anything on the SC you needed to unbolt multiple things and perhaps get a bunch of different risers and parts to make it work. Not that its bad, it's what it is (and for the price it is acceptable imo), but its something to consider before you want to say add more reach or stack to your setup. P5x is 1 bolt. You can disassemble the entire bike with 1 Allen key which is 1 size.

Also my biggest gripe was the Speed Concept riser bolt system. The bolts had a history of shearing (I am a lighter rider so I have never had this occur, but have read it happen to many people) which could result while mid ride. While you can sort of move the bolt system around to mitigate it, it was IMO my biggest gripe with the bike. I kept it very clean and greased and torqued to spec all the time, but it was the only part of the bike I really did not like. Also the brakes were a pain, but that was acceptable with rim brake TT bikes. It comes with the territory.

I will not deny that the P5x and Px line is expensive. Very expensive. However, if you have the money or find a very good deal, they are excellent bikes and IMO very, very well thought out in terms of working on, adjustment, fuel storage etc. I bought mine with absolutely no intention of getting more speed; tbh I might have lost a bit of speed with my SC switch, but for the price of half a wheel set, I got the newer ENVE disc brake wheels, a slightly shallower front wheel (which is what I wanted), disc brakes, upgrade to DA Di2 from ultegra Di2 and of course a very nice frame, integrated storage and a bike box. Not bad for throwing in under 1400USD equivalent. I do all my own bike mech work and I love working on this bike. It is just so, so so user friendly. But you can be FOP with a gen 1 ior 2 SC.

Hope that helps.

I believe this is correct. If I was doing a 40k tt i would pick the P5d every single time

After a recent accident, I had to replace my Felt IA and chose a PX
-The PX (xl) fit me better. I was off the chart on a P5d
-I like how the PX looks
-I think the P5d looks like everything else
-I am particular about my nutrition, so I carry most of what I need
-Aid stations on IM bike courses are often scenes of mass carnage that I prefer to avoid
-I like the idea of in-fuselage hydration via Yannb retrofit
-I got a good deal


Since the purchase
-Love how the bike looks
-Feels fast
-Somehow (inexplicably) a waaaay better climber than the IA.
(I am setting Strava climbing segment PRs with relatively low perceived effort)
-With the Felt IA I had to cobble together a nutrition storage/hydration system...PX well thought-out

Negatives
-Still early, but I think my ENVE 7.8's were more stable in crosswinds than the DT Swiss 1100s.

Great response. Still love my SC, but it’s fun to let the eyes wander

there is so much wrong with this post. i bought a p3x and i am a highly proficient time trialist and am extremely anal about aero decisions.

the fact simply is that the "x" series bikes are better for MOST people who do long course triathlons.

you cannot, and i repeat, cannot out "optimize" what you carry on your P5 compared to my p3x.

the only people who should be buying the p5d are those who are doing UCI governed races or races that are <90k. there's a sweeping generalization equally as inaccurate as all of yours.

I am not trying to argue around the facts that it's better for most people. I am saying it's not going to be successful in marketing so. The PX series is looking at all those bikes at Kona with gels taped to them and saying "let's optimize for that". That crowd doesn't care. That crowd will buy what shops recommend / what pros are riding.

There's a difference between the best bike and and the most marketable bike. Anne Haug is not riding a PX series, the bike looks unconventional. All that is going to hurt.

Cervelo ought to have marketed the bike as all out the fastest, and convince me that loading up the storage is the only way to go, and that beam bikes are faster than double triangles. All the marketing about the bike left the impression "it's the fastest... if you load it up (but you don't have to)... Beam bike is not the fastest, it happens to be a byproduct of optimizing for storage... Comfort was not the priority... It happened to be a by product of not having the seat post". If i am spending 10k on a bike, I would want an all out no contest / fastest tri-bike... and the P5X was not marketed as such. It doesn't help that sponsored athlete didn't ride it.

I'm doing fine on my 2014 p5-three.
However, there will come a day...

On that day I have to decide, and in the current situation it would probably be the PX.
This decision is based on one tiny point: the bottle on the Down tube.

I do long distances, and I need three bottles. One with my gels, one with water and one with electrolytes.
I do not want to use BTS bottles, because I find it awkward to reach to. I use the BTS bottle for my spare kit.
I have two BTA bottles in-line and the bottle on the down tube.
The ones for the water and the electrolyte I exchange at aid stations, so they are round. A round bottle on the down tube is aerodinamically bad on a p5. So I carry the water and electrolyte bottles BTA.
I still do not have a good solution for my gel-bottle. An elite aero bottle of 500 ml is too small. At the moment I'm fighting with a Torhans bottle which is also a bit too small for my need and from which the rubber stoppers constantly tear.

With the PX you can carry a nice round big bottle of 750 ml on the storage box over the bottom bracket without aero penalty. On the other hand I do not know if I can have two BTA bottles inline on a px (on my p5 I have a self-made solution at the moment).

Furthermore one of the storage boxes could serve to hold the battery for the electronic shifting such that you do not have to fiddle around with a battery in the saddle tube.

Weight: a frame generally weighs 1500 g or something? If the PX is 3 lbs heavier that the p5, is it because the frame is twice as heavy? Or are the plastic boxes so heavy?

The PX is 16% lighter than the P5X as stated on one post, but I couldn't find any weight comparisons to the P5D.
I took this from Aerogeeks post, ;

Simply put the P3X is everything that Cervélo learned from the P5X along with the knowledge gained in the sport over the past two years from their amateur and pro athletes alike. All that was mixed together and then iterated on again and again.

There were four major lessons that Cervélo took from the P5X:

• It was heavy (that’s a pretty easy one) – The next generation had to be lighter.
• Triathlete storage needs had changed the past few years – For instance we triathletes have for the most part made the jump from tubular to tubed (and now even tubeless) tires.
• Carbon fiber manufacturing – Since the launch of the P5X, Cervélo’s parent company had invested in overseas facilities that had state of the art manufacturing processes but still could protect their intellectual property.
• Aspirational – The P5X was the first of it’s kind and this was reflected in the initial cost. The next generation had to be more reachable (ie cheaper).

Can't beat the storage: Being this is a tri bike storage options are a must. The biggest visual difference between the P5X and P3X is the new Stealthbox 300 located just forward of the bottom bracket. On the P5X this was a large cavity (the original Stealthbox) in the bike itself for your flat needs (specifically one capable of holding a tubular tire which was no longer required). This cavity had an impact on the total weight and stiffness of the bike. On the P3X Cervélo has instead shrunk the carbon footprint and added a removable flat kit storage box.

Above the bottom bracket is the same storage box (Speedcase) as found on the P5X. This allows you to house both extra tools, a second flat kit, and emergency nutrition. You also get a pair of bottle bosses to mount an extra cage.On the top tube is Cervélo’s new SmartPak 600 bento box. The SmartPak mimics the shape of the stem to give a clean aero shape. On our test ride it was able to comfortably hold 3 gels and 3 blocks (we were worried about being left for days in the desert!)
Like the P5X, the P3X is designed to accommodate 3 regular round bottles placed in the most aerodynamic position regardless of your choice. Bottle mounts are located behind the seatpost, on top of the Speedcase, and between the arms. The thinking is that grabbing and going from aid stations is the best way to go and this requires the ability to support round bottles.

Best information on weight on the bikes are from aerogeeks

They weighed a P3X Ultegra at 9.72kg and a P5D dura ace at 8.41

For aero information. I'll re-quote cyclenutnz on the best information he gathered

https://forum.slowtwitch.com/...ost=7063114#p7063114

Here's Cervelo's video on how they conducted the test https://vimeo.com/205453884

Again, I do not see the need for the amount of storage that comes with P3X. Great for training, but I am not that concerned about aero in training. Cervelo created the bike based on their research on kona participants carried their storage. I wonder if they split that by how much cargo a P5-6 carries, vs how much cargo a P3 carries, what the numbers look like.

I suspect P5-6 riders are more likely to have actually used a bento, avoided downtube bottles, but I don't have the data to prove it. I think the intersection between people who have 11k bikes and who overload their bikes (my opinion, some may say its necessary) is much smaller than what Cervelo's study shows.

I see, you have facts, and I have generalizations :) Sorry, I missed the facts. My apologies.

Aid.dre.an, Does the P5x have an internal hydration option? Is this similar to what Hoff did to his bike (I think he stuffed a specialized bladder in his cervelo)?

It does not actually come stock with anything but I believe some people saw either the Hoff or some other athletes doing some DIY internal hydration setup and it just ends up that the Shiv bladder is the perfect size to fit in the frame. Yann did a custom plastic setup to fit the bladder in place for the top tube bento this spring which fits the shiv bladder perfectly without the use of tape etc. I think the Hoff either cut the bottom of the plastic bento out or did some DIY with the P5x top tube rubberized bento portion and used tape to place the shiv bladder in place. Both work fine, Yann's solution is just more elegant and streamlined.

It fits the P5x/P3x/Px frames equally. The difference between the P5x and the newer Px series frames is only the bottom portion of the frame (that I can notice) and they added a removable derailleur hanger, and the front end was changed up slightly with a lighter aerobar system but it lacks a bit of angle adjustment to the P5x. And the fork seems a bit more symmetrical on the Px/P3x. Otherwise I think its basically the same frame. I personally don't think I would notice a difference between the newer Px series and the P5x outside of the weight (which can be easily negated by skimping on the treats on my end).

Also, I don't know if there is a standardized way to determine stiffness, but IMO I think the information bike manufacturers release is almost meaningless at this point when you compare frames. There seems to be no actual unit of measure they (or bike manufactures in general) associate with "stiffness" and I don't see them throwing out thing like youngs modulus, and when they say its a "% increase over the previous frames" the stiffness is already very high on most modern frames, so I almost want to say its a meaningless marketing gimmick (maybe like the entire beam bike design? Who knows?). Perhaps someone can explain how bike brands standardize stiffness measurements for curiosity sake. I almost want to think that if you think the bike is fast, the mental confidence or placebo effect is all you need to outweigh any potential tangible differences that most bike manufacturers advertise.

I would pick the one that most fits my racing distance, strategy, tactics, and nutrition plan and is fastest in the wind tunnel, for me in my race setup.

The custom bladder thing looks cool. That guy makes interesting stuff. I have one of his storage boxes on my regular P5.

The thing I like about the PX is the adjustability of the cockpit... specifically tilt. This is a requirement or screening criteria for me and my position. It's also possible on the P5d, but not natively.

Does it really matter what other people do? Do what's best for you.

Eric

---

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.”

I think the P5D ought to come with the PX cockpit. unfortunately, I think most bike shops won't know this, and will continue to fit riders to the bike they want to sell, and we'll continue to see riders riding short and cramped on their P5Ds.

For the Aero minded, I think Quintana Roo probably offers the most flexibility. A slew of stem length (up to 110mm), integrated hydration (which i think is a stronger selling point that ability to hold 3 conventional bottles and 2 complete spare tires). Most importantly, it uses conventional handlebar clamps, which will be compatible with Morph-tech.

I believe Morph-tech will be more aero than any integrated aerobar bar setups can be.

Any thoughts on whether the PX as a "beam bike" provides any benefits in comfort as opposed to the traditional frame of the P5? And, does that translate to less (or measurable reduction in) fatigue over the full distance that would provide any benefit for the run? I think back to Jurgen Zach riding a Softride and at one point I believe they measured the effectiveness of the added suspension. SO if they are more comfortable, provide less fatigue and just as aerodynamic then why have they always been the redheaded stepchild. Obviously they are banned by UCI because of the design, but it seems that they aren't catching on (beam bikes) purely because of looks? They seem to resurface every few years, TJ with resurrecting the Zipp frame with Dimond, there was the brief stint of Falco, so will the PX also go via the Softride or will it get any traction?

Sure, maybe. If you could find a way to test ride it, I'd try to take it on. I was looking out for new bikes before COVID, but it would have been quite impossible to get a test ride (most bike shops around me only have 1 in stock, usually the show piece, and not for test rides).

I still think, from a marketing standpoint, the bike has to be one of the fastest bike first.

With such a radical redesign, and internal competition from P5D. I think it's gonna be a hard sell. The bike needs the perception of some clear cut advantages. I think Cervelo ought to have some high profile wins with the beam bike (e.g. what Crowie did for specialized, Badmann for Cat, Schurter did for full spension 29er XC bikes).

It's easy to pick the safer bet, and at the moment, the P5D seems safer (good enough, Kona win). Maybe beam bikes are the future, but the market needs some convincing still.

For how hard it is to get buy-in on unconventional designs, look no further than the ridicule Ceepo Shadow-R (and Cody) got on this forum. Logic would indicate that the bike must have aero merits by simply eliminating entire vertical structures. It didn't help that Andy Potts, who's not known to be very picky with his equipment also chose the Viper R. Now imagine if the Shadow-R won Kona.

According to Ben Hoffman, yes. That’s one of the reasons he rides a PX for long course.

---

Let food be thy medicine...