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About six weeks ago I wrote briefly about the new 3T Ventus bar. I haven't written about the Ventus per se, that is, I haven't yet written its product review. That's because I had to mount it on a bike and ride it.

No big whoop, you might say, just mount and ride! I'm sure that's exactly what Bjarne Riis says to his CSC riders (the Ventus is the bar on which the CSC Team races during its timed events). But Riis isn't paying me, and I'm not sponsored by Cervelo, and I'm a little more discriminating about the elements under my elbows and other tender parts.

And, it's not quite so straightforward as the choice of elements—I'm picky about my rider position. I'm 51 years old and for the last 20 years my saddle height has been 79cm, my armrest elevation drop is 15cm, and the saddle's nose on my bike is even with, perhaps 1cm in front of (depending on the saddle I choose), the bottom bracket.

If this is going to be the case—which it will be—then I've got a problem. The Ventus is a one-piece bar with an integrated stem. Since I can't change the stem length or pitch, and since I don't want a lot of spacers underneath the bar, I need to start with the bar and find the right bike from the bars back.

All this I noted in my original Part I article six weeks ago. I took my readers through the process of finding the right bike to match the inadjustability of this aerobar and the inadjustability of the rider atop it (me). That article is here. It's only right that I report on the conclusion of this experiment, that is, once I ordered the bike, did it in fact work out as all my calcs predicted? That is the theme of what you're reading here: did the experiement work?

I had several good options for bikes if I wanted to ride this bar in "my" position, and among those were Cervelo's P2C or its P3C. If I chose the P2C I'd ride the Ventus with no spacers. If the P3C, I'd have about 15mm or so of spacers under the stem. I chose the latter because I wanted some wiggle room if in fact my calcs were in error.

I'm glad I chose the bike that I did, because of something on which I did not reckon: the P3C comes stock with a headset top cap that is 20mm tall. This top cap functionally serves as your typical top cap + 15mm of spacers. That's fine, but as an aside I would suggest that Cervelo add a standard top cap to its OE kit. Were I to have chosen the P2C, the bike would've been too tall for me with this top cap.

Accordingly, I'm back to "no wiggle room" as to my position, because with this tall top cap I've sucked up all the space between the head tube top and the aerobar. So, I built the bike (and have put about 50 or 55 miles on it over its first two rides). I'll write about the Ventus bar, and other elements of the P3C, separately. My point here is simply to report on the sizing elements, that is, this is more a report on the F.I.S.T. fit system's "stack" and "reach" measures, to check on their reliability as fit predictors.

You never know how these things are going to turn out, but in this case everything functioned like a charm. With the saddle at 79cm of seat height my armrests are precisely 15cm below the top of the saddle with no spacers under the stem and 20mm of headset top cap above the head tube top. This means the P3C's "stack" of 53.5cm in size-58cm is, for this aero bar, and for my fit, precisely correct if you assume a headset top cap + headset spacers totaling 20mm.

My saddle is 1cm in front of the BB, which for me is correct with this saddle—Profile Design's TriStryke—since I sit slightly rearward on it than I do when I ride Fizik's Arione Tri 2 and other saddles. The distance from the saddle nose to the ends of the extensions, minus bar-ends, is 79cm, and the distance from the saddle nose to the back of each armrest (in a straight angular shot) is 46cm. This means the P3C's reach of 44.5cm in this size, for my saddle nose plumb line placement (that is to say, for my chosen seat angle), and for this aero bar, is precisely accurate.

I might mention, as a complete aside, that this is the first time I've noted that my BB-to-saddle top measure is exactly the same as the distance from my saddle's nose to the ends of the extensions, bar-ends omitted. I wonder how often this is the case for properly-positioned triathletes?

Yes, the P3C is precisely the right bike for this bar, for a person with my position coordinates. Is it the only production bike that would've worked for me? Felt's bikes in 58cm in the B12 and below would've worked, but I'd have needed to position the aero bar 10mm lower in elevation. This would automatically be the case if Felt used a headset top cap more typical in its elevation. But I couldn't have ridden Felt's upper-end bikes, because Felt's Bayonet fork includes a built-in stem, and this Ventus bar has its own built-in stem.

Giant's Trinity Alliance in size L is about the correct length, but has 13mm more stack. So, with a low-profile headset top cap it would've worked. A Kuota Kueen K would've been exactly 1cm too long, probably within the margin of error for Riis and his team's riders, but out of the range of acceptability for me. No problem here, as I have another aero bar planned for a Kueen K frame showing up in a few weeks.

Trek, Scott, Specialized, Cannondale, Argon 18, all make nice TT bikes that are 2cm or so too short, front to back, for the combination of me + the Ventus. Kuota's Kalibur is just about long enough, but I can't get the seat far enough forward to suit me. Likewise QR's Seduza/Caliente/Lucero. Of course I can have a custom Elite, or Guru, or Lynskey built, and because I know the intended bike's stack and reach, and the necessary seat angle, I can divine the geometry with precision, and give it the ride characteristics I want through messing with the BB drop, head angle and fork offset.

Since it was not without some quavering of voice that I enunciated my credit card number to Cervelo's chargé Betsy Hilton, it is both convenient and relieving that this experiment-in-fit is a success.