Dash Cycles is a company very much in the TriRig tradition. They're small. They're disruptive (insert Calvin sticker here). They serve a very specific market, and focus all their attention on being the best company they can be in their chosen niche. In the case of Dash Cycles<, it's ultralight wheels and saddles. And so far, no one even approaches the supremacy of Dash in this area. Their saddles quickly became my favorites, starting with their first triathlon saddle, the Tri.7. Since then, virtually every bike I build has a Dash saddle on top.
Every year, Dash Cycles continues to refine and revamp their product line, and their revisions never disappoint. In late 2015, they unveiled the new Gretchen disc, now featuring a 25mm-wide sidewall that travels straight down to the hub with no shaping whatsoever. The wide stance works well with modern frames and tires, while the straight sidewalls ensure that there's no interference with any frames or derailleurs. It's a very versatile wheel indeed. And at a paltry 810g, it's lighter than basically every other disc on the market.
,br/> The Gretchen 25 Disc is an update of the original Dash Gretchen, which was a 21mm-wide straight disc. The new Gretchen 25 is, as its name would suggest, 25mm wide. This is a better aero fit for modern frames, and offers more lateral stiffness than its predecessor. Will you notice the increase in lateral stiffness? Probably not. But will its better aerodynamics make you faster? If you ride a triathlon bike made in the last 6-7 years, almost definitely yes.
Other than its greater width, the most noticeable difference in the new Gretchen 25 is its use of 1k carbon fiber all around. The original Gretchen used a lot of unidirectional carbon, where each layer provides great stiffness in one direction, while each 1k layer provides it in two directions. Again, it's probably impossible to discern any difference in practice, but the new version should be faster based exclusively on its geometry.
The primary selling point of the Dash product over other discs is its exceptionally-low weight. The Gretchen 25 clocks in at just 810g, about the same as a Zipp 303 rear tubular, and just under the weight of a Zipp 202 Carbon Clincher! That's an amazing feat, given that we're talking about a full disc. If we compare to, say, a Zipp 808 Carbon Clincher rear, the Dash Gretchen 25 represents a weight savings of over 200g! And its aero palmares place it, at worst, in the same ballpark, if not better.
There are two principal drawbacks to the Dash Gretchen 25 Tubular. The first, of course, is its price. You'll shell out $2500 for this disc, although this is commensurate with offerings from the likes of Zipp and others. The second drawback is its thin-walled brake track. Being constructed entirely of carbon fiber, it's not as good at dissipating heat as a thicker-walled rim (like those from FLO Cycling and others), to say nothing of an aluminum brake track, the 'gold' standard for braking performance. These differences don't make an enormous difference for racing, where braking is more seldom and conditions are generally ideal, but it would be important for training, especially in the wet.
That said, Dash product is primarily meant for racing, where considerations such as price and weather are often low priorities. For training, it might not be the best pick, but who trains very often on a disc?
One final note to consider is your tire selection. Guys like Tom Anhalt, Josh Poertner of Silca, and others, have been doing a lot of work recently showing that significant performance advantages can be gleaned from paying careful attention to your tire/tube selection and your chosen inflation pressure. The best data suggests that there are a lot of great clincher tires out there (like the Continental GP4000s II, the Continental Force, the Continental Supersonic, the Specialized Turbo Cotton, etc), but fewer fast tubulars, and even fewer fast road-specific tubulars. Dash wheels are all tubulars as of this writing. So you should be very careful and specific about your tire choice when picking a Dash wheel.
All that in mind, I love Dash product. And I look forward to seeing it continue to develop as time goes on. But for now, I look forward to racing on the Gretchen 25. Thanks for reading!