Kestrel burst onto the scene in the late 1980s with a model every triathlete had to have. It was the 4000. I had one, as did all my triathlete friends. We'd ride the big roady rides, like the Como Street ride in Orange County (CA), and the roadies would say, "Get out of our peloton with your plastic bikes." This, until (Shimano's longtime employee and road race legend) Wayne Stetina showed up at Como Street with his plastic bike.

Kestrel was launched. It was the brainchild of former Trek founding employees Tom French and Bevil Hogg, along with another early bike composites pioneer Brent Trimble.

The technology was tricky, though, and Kestrel suffered from an inability to keep its paint finish from cracking as the frames flexed. While that problem was eventually fixed, it gave Trek time to catch up.

Hogg and French would soon sell controlling interest in Kestrel to Schwinn, and then ownership moved to a Japanese bank, and the manufacture of bikes was moved bit by bit from the Santa Cruz area to the Nippon Steel company in Japan.

Ownership came full circle, sort of, with four tenured employees of the company regaining control. But the thrill was gone. Trek's forethought, tenacity and muscle pushed its OCLV past Kestrel.

By and by, shrewd bicycle businessman Pat Cunnane—owner of Advance Sports, which also sells the Fuji bike line—purchased Kestrel, and the company moved in the other direction, East, to metro Philadelphia. Management of the brand has been in the hands of Steve Harad, a fixture in the triathlon industry in that town for decades.

Two years ago, Cunnane acquired Oval Composites, and it's become both an aftermarket stem, fork, wheel and aerobar company (road and tri) as well as Kestrel's component house brand.

Kestrel's latest introduction is the 4000. Again. Bringing this model back is reminiscent of Chrysler's reintroduction of the Challenger and Charger, not as lightweight, light-powered shells of their former selves, but as modern day muscle cars. The difference, however, is that the 4000 in the old days was simply an aero-tubed road race bike, ridden by triathletes (its debut, in 1986, predated by a year the Scott DH aerobar, so there was no so-called "tri geometry" at the time). This 4000, however, is a tri-dedicated bike—there's nothing road race about it.

Frame styling
If a Cervelo P3 and a Kestrel Airfoil Pro mated and had a baby, it would be the 4000. If you look at the bike, it really does appear as if it's the Airfoil Pro in almost every way, except there's a seat tube (the Airfoil Pro lacks one of these). The seat tube does two good things, and one bad thing. Good thing one: It allows the frame to be build marginally lighter, because the seat stays can go back to their traditional trophy wife job of looking good while contributing almost nothing to the structure of the frame.

Good thing two: One assumes that the seat tube fairs the rear wheel, and contributes to aerodynamics.

Bad thing: One element of the Airfoil Pro (which is still in production) that is unique and quite nifty is that the lack of a seat tube makes the frame's superstructure act like a spring. There is actual vertical compliance in an Airfoil Pro, and it provides its owners a very nice ride. This isn't to say that the 4000 rides in any way harsh, rather than it now has a seat tube, like every other double-diamond bike, so it rides more or less like every other double diamond bike.

Geometry
May I revise and extend my last remark? When I say it "rides like" other bikes I'm writing this in broad strokes. When you get into the taller weeds of the 4000's geometry, there are some pretty sizeable differences between this and other bikes. Kestrels have traditionally used road-race-like steering geometries in their tri bikes.

For example, consider Trek's Madone. The trail in a Madone is about 55mm or 56mm throughout the bulk of its size run. This is pretty typical. But its Speed Concept has a trail of 61mm throughout its size run. Cervelo, Cannondale and other companies feature tri bikes with 61mm or 62mm of trail, while building lesser trail into their road race bikes.

Kestrel's road race bikes typically feature between 53mm and 57mm of trail. But these trail numbers show up in their tri bikes as well, decreasing from 58mm in the small sizes to 53mm and even 52mm in the tallest sizes.

I don't mind this, because I like sprightly handlers. Still, these bikes are quicker in the front end than, say, a Cannondale Slice. Over the long haul—long rides—the Slice's humdrum stability is nice. Likewise when you find yourself in dicey situations, like twisty descents. The more you ride bikes, the more a particular geometric style will appeal to you. Kestrels will ride differently than other tri bikes.

Otherwise, I think I should stop and make a statement about the styling of this frame. I think it's near the top of the heap. Kestrel has always been a stylish company. When I ran Saucony's bike division (when Saucony had a bike division), we looked at two companies: Kestrel and Merlin. We acquired one: Merlin. In both cases, I confess I was awed by a sense of style—very Apple Computer—that both companies exuded.

The bikes, the brochures, really, everything about each of these companies made me stop and ask myself whether I was up to the task. I felt I could make or keep the companies profitable. But I knew I didn't possess the talent to move these companies forward in the—for lack of a better phrase—style to which they were accustomed.

Against that backdrop, the 4000 is, stylistically, a fair representation of the heritage of high style that has distinguished the Kestrel brand.

Fit
I'm again using Trek for comparison here, because Trek did something unique. Trek's view was, basically, this: The Speed Concept has so many good features that it was not going to allow the narrative of the bike to be taken sideways through a discussion of fit. Trek looked at all the important bikes in the marketplace, plotted their sizing (length and height), and built and graded the Speed Concept's sizes right smack down the middle of the market.

Because of this, I can plot Trek's size run, small to large, and this serves as a proxy for where the industry generally is. When you then consider Kestrel's size run, what you see is as follows: The Airfoil Pro gradually changes its posture, or theme, from long and low in the small size, to "orthodoxy" in its tallest size.

The 4000 does something else. You have that 650c-wheeled size, which is exceptionally low (almost as low as that in the Airfoil Pro, and that Airfoil in 47cm is the lowest bike on the planet). But if you take that one 650c size and set it off to the side, and then look at the remainder of the 4000 sizes (all the 700c-wheeled sizes) these bikes grade opposite of the Airfoil Pro. They start out in their smallest sizes (again, excluding that 650c size) moderately narrow/tall (very "Scott-like" as one large Kestrel retailer put it). Then, as the sizes progress larger and larger, the bikes get longer and longer, but they don't really get taller. By the time you get to the tallest of the 4000's sizes, you again reach fit "orthodoxy" or, maybe, go past orthodoxy and trend toward long/low.

Accordingly, the 55cm Kestrel 4000 is the most mainstream bike, fitwise, in the size run. Everything larger than that 55cm bike is long/low. Everything shorter is narrow/tall.

None of this is bad. But it's a requirement that you know what you're buying. The 4000s are not size-thematic throughout their size run.

Here's the one consideration, and, it's important, because these bikes are popular mail order items. If you buy the 4000 in either of its too tallest sizes, you're buying fairly long and low bikes. There are two typical customers for this geometric style: a person who's quite long in the torso; and a person who rides quite steep. Or both. If you ride steep (more than 78° or 79° of seat angle) make sure this bike's saddle adjusts steep enough for you. The bike itself is built as a 76° bike, and that's fine. There's plenty of length to this bike in its larger sizes. The question is, does the bike's saddle adjust steep enough?

Kestrel's geometry chart says that the seat tube angles are 76°, yet the "Forward Seatpost Position" is 79°. The 4000's seat post hardware adjusts fore/aft, like on a set of a lathe's ways, a nifty idea I first saw executed on Giant's Trinity Alliance bikes. But on these 4000s, I don't see 3° of forward movement available on its seat post clamp hardware. It's more like 1° fore, and 1° aft, of 76°.

Therefore, this is a textbook case of the need to nail your fit coordinates in advance, and only then purchase your bike. If you need the nose of your saddle to be (say) even with the BB, and you're looking at the 4000 in a 57.5cm or 59.5cm size, make sure the saddle can adjust to the plumb line position you need before you buy.

All that established, there is a new seatpost you won't see on the Kestrel website (as of this writing), that will be subbed in via a running change. It does get you more forward. And while Andy Potts won Ironman Cozumel this weekend on the existing (old) seatpost, if you need the new one, well, you need it, and make sure your 4000 has it. This new seatpost will get you to that advertised 79° position.

Groupkit
The 4000 comes with several gruppo options, from Ultegra all the way to SRAM Red and Shimano Di2. In fact, the Di2 bike is quite nicely priced at $7000. But today we're looking at the roughly $4000 street price complete, out the door, Kestrel 4000 Ultegra, featuring mostly an Ultegra group, including chain and cassette. The brake calipers are Tektro (I wish they were Ultegra), and the brake levers are the A900 that come with the Oval Concepts aerobar.

This is where Advanced Sports waxes strategic. Oval Concepts is its Bontrager, and because Oval Concepts was an accessories brand first, it's still an accessories brand. Nobody thinks twice about putting an Oval aerobar, or stem, on a bike that isn't produced by Advanced Sports (Kestrel and Fuji).

The A901 is a one-piece bar, but, it's made up of a lot of interchangeable A900 sub-assemblies. It's made to be modular, extensions, brake levers, whatnot, all switchable. It's a nice match on this mide-priced bike.

The wheels are Oval Concepts W745, and these are pretty upscale wheels for a $4000 bike. These wheels, and the aerobar, make this bike very fairly priced against other "Ultegra" tri bikes that might cost $400 or $500 less, but, can't really match the spec on the non-drivetrain parts.