The new generation of triathlon bikes are all trending towards a common theme of integration. These bikes attempt to push the limits of aerodynamic performance by mating parts together in a way not possible with the standard modular components of traditional bikes. The Plasma 3 is no exception to this rule, but stands out as the bike that retains the greatest amount of traditional construction. What does this mean? It means that the front end does have some very neat aerodynamics, but not by using parts that are unique to this bike. The aerobar is the new Pro Missile Evo, which features a standard 31.0mm round clamping surface, usable with any standard stem.
The Plasma 3's stem is the key piece to the front-end story on this bike. Yet it's still a stem that's backwards-compatible with existing bike setups. It clamps to a regular fork steer tube, and accepts a regular round bar. If you're not running it on a Plasma frame, the cables exit out the back/bottom, ready to enter your frame's top tube. However, on the Plasma 3, there's no real provision for spacers. Scott has announced that two versions of the stem will be available. One is the zero-rise version we've seen on the Pro Tour bikes, and the other is the version pictured at the top of this article, which has some rise. Beyond that, adjusting stack height is a matter left to the aerobars.
The final piece of the front end (and the rear end, for that matter) are the brakes. Other next-generation bikes have taken one of two tracks on braking, if you'll excuse the pun. One camp has gone for an integrated braking solution, like the Specialized Shiv, and the Trek Speed Concept. Others go with a non-integrated side-pull or center-pull brake, like the Giant Trinity Advanced, the Felt DA, and the Kestrel 4000. Some bikes go with a hybrid system like the Felt DA, which uses a custom rear brake, but can accept a standard front brake. Scott bucks all of these trends, and opts for standard front and rear brakes. The upside of this choice is that setup and maintenance are much easier, and for those riders who have a strong preference for a particular brakeset can still use it on the Plasma 3. The downside is that the aesthetics and aerodynamics are potentially worse than on the more integrated bikes.
So what do the measurements look like? At this point, Scott has not published the numbers. But we can estimate the geometry based on a good side-on photo of the bike. How do we do that? Simple. Every 700C wheel has a rim diameter of 622mm. Scaling an image based on that known measurement, we can easily extrapolate every other measurement on the bike that's in the same plane, including the stack and reach. The bike as pictured looks like it's roughly in the middle of the range as far as stack and reach is concerned, but different component choices could make the bike higher or lower. Stack could go about as low as 590mm with very low-stack aerobars, and reach to pad center could easily go out to 510-520mm or so before steering got to be too squirrely. This frame actually looks to fit a lot like the size Medium Trek Speed Concept, but by using a round bar instead of a proprietary one, the Scott gains some advantage in adjustability.
We will be very interested to see more of this bike as more information is released.