Rear hydration: 12 years later...
A couple weeks ago I took a long view at the evolution of bike fit, using myself as an example. We looked at how my fit has evolved over the past dozen or so years. Today I want to stick with that theme of the “then and now” of triathlon bicycles, taking just a quick look at how we store hydration at the back of the bike.
A dozen or so years ago, there were basically three ways to go. Some folks skipped rear hydration all together, and left nothing behind the saddle. Some folks used some kind of monstrosity to store their entire carry-on worth of luggage behind the saddle. Then other folks, usually at the pointy end of the race, tended to stick to a single bottle, usually tucked pretty close to the back of the saddle if not zip-tied right to it. This is the Chris Lieto or Craig Alexander school of rear hydration.
Fast-forward to today … and we basically still have the same three camps. There are a few more options in how to fit yourself into one of the three camps, but they’re still basically the same. Empty saddles, minimal setups, and maximal setups. Let’s think about why and how you might want to add a bottle behind your saddle, and the slickest way to do so.
Rear hydration is best thought of as a “reserve tank.” This isn’t a spot you want to be reaching back to every few minutes, because it’ll ruin your aerodynamics as you ride down the road, disturbing a lot of the air around you which can take a while to re-settle. So if you use rear hydration, you want it to be something you go to just once, either taking a bottle from back there and replacing an empty front cage between your arms, or refilling some kind of refillable solution up front, then replacing the empty bottle in back or chucking it at an appropriate spot along the course.
And as long as you set it up properly, the bottle and cage themselves are likely to be aero neutral, sitting in a wake behind your butt. This is of course dependent on your exact equipment and position, but generally, any single bottle in the back is likely to be aero neutral, no matter how you set it up. Maybe the best public piece of information on the aerodynamics of rear hydration comes from Cervelo, who ran a set of sets back in the early 2010’s. They tested a single bottle, double bottles, close to saddle, far from saddle, higher up, and lower down. With their particular test athlete, none of the setups seemed to make any aero difference compared to no rear hydration at all. And while those results might not hold true for everyone, it’s probably safe to say that as long as you tuck things in nice and close and aren’t toting an entire suitcase back there, a saddle cage is a fantastic aero-neutral place to store a single reserve tank of fluid.
But HOW exactly should you mount it? A dozen years ago, the slickest method was to just zip-tie a cage right to your saddle rails. This takes a little bit of finesse, some cages require drilling, and you need to get everything just right in order to keep it stable and reliable. If you want to do this today, just grab one of our own Kappa or Kappa Saddle cages. They’re built with pre-molded slotted holes for exactly this purpose. Just thread the zip-tie through these holes and around your saddle rails. Four zip ties is all you need.
Of course, if you want a little more predictability in how things are set up, we also recommend our Beta rear carrier. These can be used on any standard saddle with our Beta Saddle Bracket, or on any seatpost with a Ritchey 10mm rod mount. The Beta lets you easily run either one or two bottles; maybe put on two bottles for training or long-course racing, then switch to a single bottle for short course or well-supported longer races.
In short, the more things change, the more they stay the same. I find this stuff fascinating, and I love developing products that help athletes achieve their goals and find their own definition of success. Stay tuned, because we have a lot of ideas about how to improve things in this space.
