From an Aerodynamic perspective, is there any advantage/disadvantage to running a single vs double rear seat hydration setup? If I interpret xlabs site properly, running a rear hydration kit actually makes you faster in some circumstances. I was wondering if I would be wiser to get a single or a double. Any sharing of perspectives would be appreciated. Thanks.
I tried both last season. Did not notice any significant difference between them as far as power / speed / etc. Everything I read indicated that neither setup really had an aero penalty.
What I did notice is that my short arms had a really hard time getting to the single bottle holder.
Just get a setup that can be changed from one bottle to two. I use a Profile Design version, but there are probably hundreds out there. I’ve used both, but usually just go with one bottle behind the seat.
A two bottle setup has a greater chance of sticking out into the wind depending on your body shape, though if properly positioned this shouldn’t be an issue.
One advantage of a single bottle setup is that you can just use zipties instead of buying an mounting system that adds weight and cost.
I have a hard time reaching the back bottle I have a single. I ended up putting a mini pod with all my tools and flat kit in the behind the saddle cage and went with a bta bottle. I own a shiv so I use the fuelselage integrated hydration system as my second bottle.
I have a double behind the saddle. This season I’m going with one between the aero bars and the 2 behind the saddle. I know I can get away with a single behind the saddle but I don’t feel like buying another setup. Would you guys agree the double behind the saddle is a better choice than having the 2 frame mounted bottles?
Some good insight from Jim at ERO on this thread:
I used a double plus a BTA the past couple seasons, but I rely on Infinit for nutrition in a 70.3.
I’m contemplating my options for a full Ironman because I can’t see carrying 4 bottles to get me through a 6 hour bike split.
You need to concentrate the mix into a single bottle and either train yourself to be able to injest that directly or dilute it with water in a BTA torpedo bottle on the fly. I can get 2000 calories of Infinit into a single 26oz bottle
I didn’t think that would even dissolve.
I’ve got an iron gut so I probably wouldn’t have any issues with it.
I prefer using a two bottle set up. It is defiantly a more comfortable reach for the bottles and help me not get out of a tight tuck. Your legs are in front of the double bottles and the single bottle is set farther back subject to wind off your back.
What I did notice is that my short arms had a really hard time getting to the single bottle holder.
This. Rear hydration sucks, not worth it. Especially when you are 50+ like I am. I simply cannot make the reach without risking life and limb and exposing my entire torso to the world and the wind. I will take the aero penalty to have a bottle on the seat tube, if there is an aero penalty.
If you are considering rear hydration, ask yourself this. Will you end up “sitting up” for 30 seconds to drink? If so, you just negated your aero advantage.
Exactly and you can also get some aero bottles for the frame to minimize the drag.
So I use gels but didn’t want to carry a dozen or whatever the number was last year so someone suggested diluting with water in a bottle and then I alternate water gator are at aid stations
This year same plan but concentrate in x lab bta and water behind the seat
We’ll see how that works
.
recently been having this dilemma with my P2 Cervelo. i already have my FC35 aero bottle, and the Razor2 aero bottle on my down post… but you know, i wanted to be able to carry more if necessary.
so i got a second-hand two-bottle holder for the back of the saddle. however, i think it’s going to be a lot of liquid to carry. i mean, so far i’ve done mostly short course races where the FC35 and the Razor2 will be enough liquid. i’ve done one 70.3 where on the bike course i hit the bottle exchange station four times, plenty of opportunity to refill my aero bar bottle. and i’ve checked out 140.6 course maps- there are at least 4 aid stations on the bike, and you generally hit them twice. is there really a need to carry so much on my bike when it’s available to me on the course?
I feel the 2 bottle rear holder is more for training when you want to ride long without having to stop and not really so much for racing long course.
Personally I use a single rear bottle holder.
jaretj
I am training for my first 140.6, and run a Torhans aero 30 up front and have a double rear hydration carrier. I’d thought about putting my 2nd bottle of infinit in the bike special needs bag. Instead of carrying it. Does anyone stop at special needs or just carry all of your nutrition?? I’m currently running approx 900 cal/ 26oz bottle on the rear, two will bottles will get me all of the nutrion that I need for the bike leg. I just can’t decide if it’s better to carry both and not stop or plan to stop as I expect that I’ll need to go to the bathroom anyway.
I feel the 2 bottle rear holder is more for training when you want to ride long without having to stop and not really so much for racing long course.
Personally I use a single rear bottle holder.
jaretj
good point.
Can anyone running a single rear bottle recommend a particular brand? I’m using an ISM Adamo. Want to switch from a double to single for my racing.
Xlab delta 200.