Slowman wrote:
what ARE the set ups?
It's the right question. The answers are in your inbox, but I'm happy to expand upon them a bit and share with the community and public in advance. The report will have every component and setup annotated and delineated, and pictures of each test rig will be offered from the front, side, back, aerial, etc.
Broadly, the principal goal from the outset was to align as many variables as possible. I'll vomit up a lot of detail here for those who are inclined, but the tl;dr is that we thought of everything and have aligned almost everything as best as is practically possible.
Size: I feel comfortable riding anywhere between 560 and 575 on the stack, and anywhere between 465-480 on the reach. Because I am the rider on board, the sizes of each bike needed to allow for these ranges and needed to work vis-a-vis each other. This wasn't very ambiguous, because for most of these bikes -- the Andean, the Felt, the P5, the Ventum, and the Tactical -- only one size exists that worked or one size that worked without material modifications (like hacking the Tactical's extension placement, which was considered before we pushed back the test date) or huge amounts of spacer stack. I'm 5'8" 145 lbs and ride aggressively -- there simply aren't that many bikes that fit me in multiple sizes when I'm at the floor of 700c geo designs. The P5-X is unique -- it's one of the only bikes that I know of that fits me in its stock form in three sizes. Luckily the medium is what was made available and the medium is what makes the most sense to me. I'm at the bottom of the stack envelope there in the lowest configuration. It's the size I would buy were I to win the lottery and be able to afford the P5-X.
Despite my best efforts, prescribing final stack and reach values is a work in progress. I thought we had aligned on 565, but the P5 is at 570, so the reality is that we are going to need to bring the other bikes
up to meet the highest (lowest?) common denominator in stack. I think we are good hitting 475-480 reach in all sizes.
In sum, the fit was partly input and partly output, but ultimately the key was to make sure everything was the same for the coordinates that matter. We have an x/y tool from SICI -- thanks Gary from Purely Custom coming through here -- which will true up any discrepancies between the fits.
Front End Spec: Every front end is stock except for the Felt B series, which has the Enve bar. The Enve bar is one of two bars available that allows me to hit my stack on that bike -- and both require undermount configuration. The non Enve one is no longer produced, and I have cracked two of them at that clamp, and ended up selling the third to fund the Enve purchase.
With Premier, P5-6, and Tactical, there is no other sensible option, and I couldn't think of a reason to swap the bar on the Ventum.
There are a number of after market bars that will fit the Andean, all of which I considered, but all of them were going to be inferior than the stock Corsair. It's hard to describe, but the way the stock Andean stem flairs out renders most bars non-starters, unless you want to take a hacksaw to it (like Jordan). The Andean's bento storage and hydration integration and the junction between the stock stem and the steerer/top tube are unique, and while you could use a third party bar/stem combo like the Zipp Vuka Stealth, it would look like garbage and likely be a dog aerodynamically -- which is also why Jordan is running the Vuka Bull with the hacked up stock stem, I presume.
Pads/Cups: Even though you didn't ask, others have and I wanted to touch on this. We are also trying to strike a balance between normalizing the shape of the pad and using the pad that provides for the closest match in reach and pad width. For example, the Andean pads are the stock Corsair ones, while the Felt B series pads are my preferred Profile Design pads. The incongruity here is acceptable because we think pad x/y is more important than totally consistent cup/pad architecture, as long as the frontal area of these cups/pads are quite similar. In this case, we needed to use the Corsair stock cups to hit my reach, but aerodynamically we think there will be no difference, as the shapes are almost identical to the PD version. We have multiple pairs of PD pads/cups and a few other options like them (with more holes) to facilitate equivalent setups on this.
Extensions: My preferred extensions are the Zipp Evo 110 Carbons. I don't know if they're fast, because I haven't dutifully tested, but they're comfortable. With the undermount setup on the Felt, they put my hands in a comfortable and eye-ball aero position. Because of how they are designed and how you can cut them, they are also a good choice for standardizing hand position across the board.
Anyways, all bikes except the Premier Tactical -- which has proprietary extensions/clamps -- will have these extensions. The cockpit length on all bikes will be identical. The rise above the pad will be as close as possible, given the obvious constraint of
where the actual extension clamp sits on the front end in question. Even while the Tactical extensions will have a slightly different shape, we think the length and rise can be normalized to acceptable tolerances.
Cranksets: All 165mm 52/36 across the board. This was non negotiable. P5-X and P5 came with 170s -- non starter, so we have gone to considerable effort to swap BBs, etc. Position wise, I am sensitive to even minor changes in crank length, and of course a change in crank length changes the position. It's hard to imagine ring spec meaningfully impacts aerodynamics, but better safe than sorry here. We have four 165 52/36 cranks at our disposal, and all bikes are being set up to accept GXP.
Wheels: There is only one firm in the industry that is producing an optimized disc brake rim and optimized rim brake rim of same depth, product spec, etc., and that's Enve. We are using the Enve 7.8 SES rim and Enve 7.8 SES disc. I have effort to acquire these, including selling my Zipps, even though I think the Zipps are superior.
Hydration/Storage: I think you saved the most challenging for last. This question has plagued me. I mean that literally -- I woke up with nightmares about second and third bottle setups one night last week.
Garmin and flat kit will be carried as I do/would (with very little aero penalty, presumably) for those bikes that have no accommodation in the design.
But the hydration issue is murkier. I am setting up front hydration on the Felt B Series, Andean, P5, P5-X, and Tactical either the way the manufacturer has recommended or the way I would, which are congruous here. Ventum's design is such that no additional hydration is necessary -- or for Ventum, advisable aerodynamically, even though they say that the BTA impact can swing either way depending on the individual.
Rear hydration is an even more challenging issue. As desert dude noted, Cervelo had problems setting up identical BTS systems from bike to bike (or did so in cases where it made little sense, like on the Ventum). The grimmer reality is that BTS setups can either help or hurt from bike to bike based on individual elements like slackness/steepness of saddle position; type of saddle; effective seat tube angle of the specific bike; protrusion and/or shape of the seat post; and even width of the rider's hips. So by tossing on rear hydration to all of these bikes (Ventum excepted), you don't actually know whether the BTS setup is helping or hurting, aerodynamically. You wouldn't actually know that unless you tested every single bike and setup as a kind of tournament, which we don't have the resources to facilitate (manufacturers don't either).
We are damned if we do, damned if we don't on second bottle/BTS inclusion. If we include it, we are introducing noise into answering the question of which bike is fastest. We are introducing a variable of which we don't know the impact. If we don't, we aren't lending support to the reality of the most typical long course setups. Ventum has a point about "race trim", after all.
The compromise goes like this. We hope to have time to test a limited sweep of BTS setups -- maybe only on two bikes. Perhaps we will have time for -5,0,5 but the hope is to have a full sweep for two bikes and two different BTS setups. We will simply not have time to test BTS setups on every bike. It's not happening without a serious donation. Failing that, and even possibly in addition to that, Brian and Heath have offered to let me scavenge their historical (anonymous) data from Aero Camp riders who have A/B/C tested this variable. Similar to error bars, we would inject into the model "BTS bars" if you will. So every bike except Ventum would get a range of CdA values both positive and negative by which a second or third bottle may impact their aerodynamics. I can work to make this more of a weighted average, or, if there is statistically significant data available, to identify covariates or explanatory variables to better apply these ranges on an individual basis. For instance, females (with larger, child bearing hips) often test better with two bottles BTA than the Stover's of the world. Sebastian Kienle runs two bottles and Frodo runs one -- do you think that's informed by chance or data?
Sorry to vomit words here, but I had a lot to say about this and I know there are at least a few nerds around here who are going to be into every last detail. I also didn't have time to proofread, so hope this makes sense.
Thanks again, everyone, for your support.