Old P2 54: 51.2, 41.8
New P2 54: 52.2, 41.1

I see Trek did that with their "pro" fit bikes with low head tubes and also only made whatever sizes they also made for the team. I think Specialized used to sell the low-head tube Tarmacs but I don't think they ever sold the low head tube Roubaix bikes with 30mm tire clearance. No doubt there are a couple rolling around Morgan Hill. We did some special bikes for Garmin and then Argos for the cobbled classics and I was always worried they'd run afoul of the "no for public sale" UCI rules. They also had one-off CNC dropouts w/o lawyer tabs for faster wheel changes and precise thicknesses so all the QR could be set to the same pre-threaded position; I'm sure JV, Matt and Co made the same requests for you guys. We never sold them commercially though.

I'm not a Cervelo customer but with the current market trends I'd think an RCA Mud made in China with thru axles and disc brakes would be awesome and everything the non-UCI racer would want.

Hope to see you and the new toys at Eurobike,

-SD

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https://www.kickstarter.com/...bike-for-the-new-era

Hi Damon,

So just to clarify, is the R2 frame the same as the current (2014) R3 Ultegra frame, as opposed to the current R3 105 frame, which I think is the prior generation 2013 and earlier R3?

Thanks.

Correct. One way to tell is by the internal cables, rather than external.

Cheers,

---

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

Hi Dave,

Yep, I noticed the limited size run at Trek, too. We finally got busted by the UCI for the Mud bikes after VeloNews did a write up before Paris-Roubaix, I think it might have been the year tall Johan Vansummeren won on his 61cm(!) R3 Mud. Luckily we had produced a few extra frames and were able to satisfy the UCI by selling them. All gone now! :-(

Yes, hope to see you at Eurobike!

Cheers,

---

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

Hi kjmcawesome,

All 700x25C tires should fit fine.

We designed the frame for the biggest 700x25C tire we could find at the time, a Vittoria Diamante Pro Light we measured at a whopping 28.67mm wide. Since then some wider rims have been introduced, so if you're pushing the tire width be sure to check.

Cheers,

---

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

Hi dork,

Nice summary! Off the top of my head I don't see any great errors, except your last row: In fact, the current P2, produced in the P3 mould, uses the identical carbon fibre type and layup as the P3. It is the P3 frame. Only the fork, paint and parts make the bikes different.

Most (all?) of these P-series models, in all their naming confusion, are summarized at cervelo.com under Support, in four glorious pages of photos, manuals, and yes, geometry tables.

http://www.cervelo.com/en/support/products.html


Cheers,

---

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

We thought some of the same things. (Great minds think alike. And so do ours! :-)

But, to use the P3 seat stays as an example, that part of the frame was really tricky to mould and bond, which is the main reason the P3C cost more than the P2 in the first place. The reason we spent the money to do it was to reduce aero drag, by extending the seat tube cutout to cover more of the fastest moving part of the rear tire and wheel at the top. We got a significant increase in speed, but there was just no way to put that feature on the P2 without raising the price ... to the P3 level.



A similar cost increase exists from the S3 (partial seat tube cutout) to the S5 (extended seat tube cutout).

Cheers,

---

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

i ride a 2012 P2....in my mind, it is the best of the older P2's. Why? its geometry is/was still long and low, it had the decent black paint job with red accents and it was ultegra everywhere as standard. Also the bars were carbon 3T aura pro's. The 2013 P2 (yours?) went to a silvery type of colour, had a downgrade in components and the bars went to a cheaper profile design model or something from memory. The 2014 model, however, is a different kettle of fish.

Are you trolling, Mr Rinard? ;)

I have a couple of questions I've been thinking about. The first is whether you have done any analysis/simulation on weight vs. aero in typical critical road race situations. What I'm specifically thinking of can be exemplified in the nationals here this year with 15 loops on a course that had one major climb (1 km, 7% - about the biggest climb you can find around these parts). Obviously, the race was largely decided on that climb as that was where most of the attacks were made. To be crude, the race could be divided into two determining parts:

1. Endurance/exhaustion part (e.g 5 hours at 240W avg), if you can't handle his you will be dropped before the race is over.
2. Explosive part (e.g. 2 min at 500W up the hill with some bursts in it), again, if you can't handle this you will be dropped on the hill.

With an aero bike you will come out ahead on the first part, let's say you save 5W (in the draft). With the light bike you will likely save some on the second part, let's say 5W (if you go lightweight with both shallower wheels, light frame, etc.).

From this comes two things (well, probably more...). First, if you get dropped on the explosive part you will lose the wheel in front giving you more drag for some length of time - forever if you get dropped completely and can't make it back. Second, maybe different rider types would benefit from different bikes? Some may find it easy to go 5 hours at 240W so could care less about a 5W improvement there, but really struggle with the explosive part - and vice versa.

Also, corners are a road race classic with bursts. If you ride alone I get that an aero bike will usually be faster. But in a race you often follow a wheel, which means both that your drag is lower (so you save less with aerodynamic equipment) but it gets higher if you can't follow the wheel in front, so.e.g. you get a 20 cm larger gap with a heavier bike. How much drag does this cost? Have you simulated these sorts of things rather than just the 'going up a mountain alone' simulation?

Second question, is there a specific reason you don't sell the 2 series frame-only? Or rather, why you sell the 3 series frame-only when it's about the same cost as a 2 series bike with components? Seems pretty weird. Is inventory-driven, image-driven, or something else?

I see SuperDave took care of the UCI legal thing with regards to the Mud fork - because it didn't seem legal to me :)

Hi MTM,

Very insightful thinking.

Of course, you're familiar with Col de la Tipping Point, a.k.a. Weight versus Aero on our web site. http://www.cervelo.com/.../weight-vs-aero.html
Riding alone, aero is better for every rider on every road, until the up hill is so steep the speed drops enough so that a lighter bike is the same speed as a heavier aero bike.

Then there's also "Aero in the Peloton," here: http://www.cervelo.com/...-in-the-peloton.html
As you mention, the aero benefit decreases (but doesn't vanish) when riding in a group. Even when drafting, aero drag is still the biggest consumer of your power. Until a very steep climb...

Which brings us to your insight: the best bike for a hilly course might be different, depending on rider profiles. For example, I love a fast echelon on rolling terrain, but my colleague David hated them. One day we were rotating beautifully, I was so happy I said "David, don't you just love this?" but he answered "NO! I can't wait 'till we get to the hill, so I can rest!" I was shocked, and finally realized not every rider experienced the course the same way I did. David didn't need a light bike; he needed an aero bike. So consider your strengths and weaknesses - if your critical moment in the race is on the climb, look closely at the math for that section: gradient, weight and aero differences, etc. and decide if the light bike might serve you better. But if, like David, your critical moment is on flat or rolling terrain, then probably the aero bike will help you race better overall.

It's this kind of thinking that makes a good pro team choose different Cervelos for different riders and different events. Team Garmin-Sharp's sports scientist Robby Ketchell wrote about that on our web site here:
http://www.cervelo.com/...-robby-ketchell.html

For your nationals course, the 7% grade is within the range of tipping points (5 to 8%), where the aero bike and light bike are often close in speed. But as you mention, that's for solo riding. In a group, during hard uphill attacks, power and speed are higher, which makes aero more important than during steady solo climbing, extending the tipping point to higher grades, about 1-2% steeper depending on rider weight and power. Assuming rider body types typical at a nationals level race, I'd choose the aero bike, even based only on the up hill and not considering the rest of the course.

You also asked about accelerating out of corners. Corners are exited at speed, so the expected faster acceleration of the light bike is actually a myth; in fact the aero bike accelerates faster than the light bike. (Only from a standing start is the aero bike slower, and then only for the first few pedal strokes, after which it catches and passes the light bike.)

Cheers,

---

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

Damon,

In a day and age where an aero bike IS a light bike, why do we still look at both of these in a different light. If you are riding to UCI rules then 6.8 kg is the rule and you should have the most aero road bike possible at that limit. If you are not riding a UCI event and you can have a lighter bike, you can still have a very light aero bike. I have always looked at these as a single component were aero always trumps weight BUT weight does matter. Aero saves your minutes and weight saves you second most of the time but as you mentioned when you get up to a tipping point then weight can save minutes but aero is saving second.

I think it is a mistake to look at these separately and everyone should be riding the most aero, light bike they can afford.

Hi BMANX,

We think the same. Speaking for myself, my personal "ultimate road bike" isn't a round-tubed light frame that takes 25C tires; it's my S5 VWD, with a frame lighter than most companies' "light" bikes, yet it's the most aero road bike in the world. At the end of a long all-day adventure ride, dead tired, sun going down, and the last 30 km are into a headwind, I want every part of my bike (and body!) to be aero.

Light or aero? You can have them both. (Theoretically, of course. I'm lucky, I work here, I could never afford this otherwise.)

On the other hand, a lot of the composite layup magic that makes the S5 VWD so light, came from Project California - and that light technology can bee seen in its most pure expression, in the lightest production frame in the world: the Cervelo RCA at just 667 grams. It's not as aero as the S5 VWD of course, so there will always be the question: Aero or light?

As you mention, for racing under UCI rules, it's amazing to me to see pro riders like Contador and others, choosing obviously un-aero parts when aero ones are available, "because it's lighter," when the team just has to add dead weight in the end. (When I moved to Canada I learned UCI rules apply in most of the world, amateur or pro; the US is the exception, though it is a large market.)

Cheers,

---

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

By "Old P2" I mean 2013 P2, the one you bought.

I'm curious if cervelo has quantified saddle deflection for their various models?

People on ST tend to dismiss frame/seatpost comfort aspects, but the velonews test below showed about 3-4mm of difference in deflection between the best and worst seatpost and the test didn't include any of the newer seatposts like syntace hi flex or the ergon cf3. It seems to me, the potential for seatpost deflection contributing to comfort is equal to that of going from a 23 to 28mm tire.

http://velonews.competitor.com/...m-your-post_267560/4

Damon,

I'm hoping you can help me with a decision I'm trying to make. I'm currently on the fence between the S2 and now R2. There's obviously the weight vs. aero argument and what best fits your needs of the bike. My question to you, is now that the S series shares a similar geometry and rear triangle design with the R series, how close does it come regarding all day comfort? Is it now so similar that the only difference in the two is weight vs. aero?

Thanks for being here to answer all of our questions!

Hi Runless,

Yes. I don't have much time (just leaving the office for an appointment), so I apologize for being brief, but basically, two things:

1. Comparing two bikes (R5ca and S5 Team), with the same wheels and components), the difference in vertical compliance is just 1%.
2. The tires account for the bulk of the total deflection.

Bottom line: look first at the tires.

Cheers,

---

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

Hi nikenum9,

Hope my answer above can help.

Cheers,

---

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

 Which makes me wonder why the Garmin-Sharp team seems to consistently choose the S3 over the S5 for road stages?

Hi craigj532,

This article "Pro Bike Choice" might shed some insight:
http://www.cervelo.com/en/engineering/ask-the-engineers/pro-bike-choice-by-robby-ketchell.html


Cheers,

---

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)

Weird, I thought it was a budget thing somehow.

---

The point is, ladies and gentleman, that speed, for lack of a better word, is good. Speed is right, Speed works. Speed clarifies, cuts through, and captures the essence of the evolutionary spirit.

I guess, I'd be curious to hear more when you have a chance. How do you compare a bike that accepts a standard post to one with an aero post? What's the test method? In bikes that accept round posts have you tried non setback aluminum versus something like the ritchey flex logic or similar?

Hi Damon,

I've been waiting for 2014 R4 model with 105 11-speed, but now it is R2.

Is this an absolute R3 frame, not just based on R3 frame?

The only different is the new fork that allows larger tires?

Does it come with only color white?

I've been thinking to get the 2014 R3 and have the dealer to install 105 11-speed, but the dealer it would cost almost ast getting the 2014 R3 with Ultegra.

If your answers to all three questions as "YES", then the only thing I have to think about is the color (of course, I love the black/blue 2014 R3).


Thanks,
Van

Damon,

While we're on the subject of history, I have one of the ~2007 era R3's with the 32.4mm seatpost. How and why did you guys come up with that? Fortunately Thomson still makes them, but that size hasn't been seen on a road bike (I think) since!

Note - I think I asked you about this a loooooong time ago and you said you'd get back to me after the S5 launch. So I think we're due :-)

Hi Jesse,

Sorry for my (years!) late reply.

Our mission is to make you faster, and we believe riders want the best bike possible.

The odd seat post diameter came about as one of the outputs of the C-TOP iterative parametric software Cervelo engineers wrote (in 2004) to automatically run a wide range of dimensional parameters through FEA to discover the first Squoval tube shapes, as implemented in your R3. It was marginally better than a 27.2 post, but at Cervelo we've always done everything possible to be even a little bit better, so we went with it. Campagnolo, FSA, Thomson and a few others supported the size for many years. We go so much push back that within a few years we switched to the more common 27.2 diameter. You can also get a shim to reduce your frame to fit 27.2 if you want.

Cheers,

---

Damon Rinard
Engineering Manager,
CSG Road Engineering Department
Cannondale & GT Bicycles
(ex-Cervelo, ex-Trek, ex-Velomax, ex-Kestrel)