Giant's Trinity Advanced SL2

Have you noticed? There is a new class of timed race bicycle manufactured these days. Giant, Scott, Specialized and others are working on, or have finished, bikes that integrate frame, fork and aerobars seamlessly, removing the stem from the unit altogether. Let's take a look at one of these bikes.

Giant was the first to come to market with a bike of this type, and it's called the Trinity Advanced. The SL2 is the bike overviewed here. It's UCI legal, which means it's "tubes" form a double diamond shape, with a level top tube, to keep these bikes appearing "traditional."

Nothing much traditional about the Trinity Advanced. It's got a stem which isn't really a stem in any recognizable sense. The stem is made up of a top and bottom clamshell piece that envelopes the pursuit bar. The bottom piece doubles as the leading edge of the head tube.

There are three sets of stem assemblies, and they're represented in the graphic below. Position-wise, they differ one from the other only in height, that is, they're all the same length. That length is "94mm from the top of the headtube" to the armrest clamps, according to the bike's product manager.

"As AeroDrive is a specific front end, the stem length doesn't exist," contends Giant, and that's true as far as it goes. Why do we care how long the stem is, on a bike that has no stem? Several reasons.

First, because of fit: Absent Giant and the bike fit community coming together with a determination of how long this bike is, you won't know if you can fit on it absent having the bike in front of you. Unless Giant is extremely successful at selling through all three sizes in many of its locations, that's a barrier to sell-through.

Second, because of steering: Some call it "steering lever," some call it "tiller," and it's the distance between the steering axis and the steering contact point (the pursuit hand positions is such a point). Whether in the aero position, out of the saddle, or seated while on the pursuits, the length of the steering lever is one determiner of the quality of the bike's handling.

Third: weight displacement. The longer the steering lever, the more weight is cantilevered in front of the steering axis.

As far as I can tell, this bike's steering lever is fairly long, that is to say, if you took this bike's full scale mechanical drawing and drew in a stem, it would be a bit out there. This, because you must add to 94mm the distance from the aerobar bracket forward to the "virtual handlebar clamp," and also the rearward distance from the head tube top to the center of the stem clamp canted back at 73° (this bike's head tube angle).

What causes me concern about the Trinity Advanced geometry is the relatively steep head angle, the apparently longish "virtual stem length," and the short front/center measurements for the three sizes (571mm, 595mm, 609mm). Were I this bike's designer, I'd probably add 3cm to each size's front/center through shallowing the head angle plus adding fork offset, along with lengthening the bike's cockpit (i.e., adding reach). I'd compensate by shortening the virtual stem length (if I've calculated that right).

But the saving grace of this bike is its choice of a fairly pedestrian 61mm of trail. This slowing down of the handling is how Cannondale, with its 62mm of trail, "fixes" the Slice's somewhat shorter (versus, say, Felt and Cervelo) front/centers.

I haven't ridden this bike, but it's is probably going to be a nice handler not counting the dicey sections of a dicey course, say, on the descents in a race like Wildflower, or Monaco 70.3. A lot of your weight is going to be on the front wheel of this bike when descending and cornering, so, we'll have to see if this is a non-issue or whether the bike takes care of high speed braking, cornering, and descending.

Back to fit: The only fore/aft front-end adjustability on this bike is 15mm of length adjustment on the armrest pad. In a sense, then, this is like buying a 3T Ventus aerobar for an existing bike that you have: The stem is fixed, there is no adjustability.

There are two things that make the above statement not precisely true. First, as noted, the front end of this bike is exceedingly adjustable in the vertical plane. Upsy-downsy, yes, you're in very good care here. It's backsy-forthsy where your adjustability is extremely limited. The bike ships with all three available "stem-like" mechanisms, so, to recap, this might be the most height-adjustable bike on the market today; it's just not very length-adjustable.

Second, if you buy a 3T Ventus one-piece aerobar, at least you have the ability to match that bar to a frame. For example, when I wanted to road test the Ventus, I simply placed this bar on my Exit Cycling fit bike, adjusted the fit bike to match my personal fit coordinates, read the stack and reach readings off the Exit fit bike, and then matched these to our stack and reach database. There were three bikes on that database that had a stack and reach within 5mm in each axis, and I chose one of those bikes as the bike I would ride underneath the Ventus bar. With this Trinity Advanced bike, this one-piece bar mates with this particular bike. You're boxed in to the length of this particular bike's frame + stem.

So, here's what you must do. First, you have no business buying this bike unless you know your fit coordinates. If you don't know them, discover them (you need to know them anyway, for any bike). Look on my user profile, you'll find my fit coordinates for the bikes I ride. You need to know your fit coordinates.

Next, you need to take the Trinity Advanced and set it up on a trainer, put the saddle where it needs to be (the rear end of this bike is well thought out, geometrically, so, getting your saddle where you want it to be shouldn't be difficult). Then, figure out where your armrests need to be on this bike, based on your fit coordinates, and see if you can get them there.

Only then are you ready to buy this bike, assuming the rest of this bike matches your needs.

Fortunately, there is one thing that is modular on these bars: the extensions. I'm very picky about extension shapes, and Giant did you and it a favor by making the extension 22.2mm in O.D. This means you can take anyone's extension and slide it right in, if you don't like the extension provided.

The seat angle is advertised as 78° though, as you'll note, the seat mast points up almost vertically. Giant figures this 78° is about the seat angle when the bike's saddle is positioned in a place about average for the specific mold size. One of Giant's nicer features: that seat post clamp hardware that moves fore/aft on a set of "ways," like a lathe. That feature's been out for several years now, so, I'm sure it's quite functional in an age when getting the saddle to stay put on your high-dollar tri bike is not always a given.

The bike overviewed today is the Trinity Advanced SL2. I chose this bike because it's the most affordable of the three ways this frame is spec'd. For $5500 complete, the groupkit is Shimano Ultegra, more or less. This caveat because the brake calipers, front and rear both, are of Giant's own design (bravo instead of simply spec'ing Tektro's regrettable calipers made for behind the fork and under the chainstay). More and more, these bikes are built like motorcycles, where you don't buy a Honda frame and some other company's parts, you just buy a Honda. Therefore, the groupkit idea is slowly giving way to what Giant's got here, where the aerobars, stem, base bar, brake calipers, seat post, the wheels, and so forth, and now just part of the bike.

Let's remember why this bike was designed. It's for Giant's pro teams, now primarily Rabobank. It sprung out of its relationship with High Road (the team that now rides Scott's bikes), and that collaboration seems to have pointed Giant in a specific design direction, though Giant is adamant about the Trinity Advanced being its bike and its technology. The point is this: The bike written about here is all about aerodynamics, and is designed to accommodate very powerful riders who perform at very high speeds, relative to you and me. Accordingly, it is only fair to note that when a frame fails to do everything I want it to do in the way I want it to do it (like, length-adjust) it's because of the constraints aerodynamic features put on the normal functions of the bike.

I'd like to be more substantive about how this bike is going to ride, how comfortable it's going to be at the contact points, how it will fit you, and what geometric category to place it in. But I'm still a bit mystified and will be until I get one in my hot little hands. It smells, tastes, and sounds like a "narrow and tall" bike as we categorize these things, so, a Scott Plasma, a Cannondale Slice, would be in its geometric set (ironically, I don't know that this bike would really fit and ride like a Giant Trinity or Trinity Alliance).

If it were outfitted with a particular stem, and Visiontech, or Profile Design, aerobars, I'll know a lot because I know how those bars ride. This bike is going to be a bit of a mystery until ridden. The Trinity Advanced is sexy, but it's also positively Rumsfeldian, with known unknowns and unknown unknowns. The onus is Giant's to bridge the knowledge gap. Your job is to look at this bike and drool. Mine is to divine and deconstruct, and when I know more about the Trinity Advanced, you'll know more.