Congratulations on your new Felt.  I am in the same boat.  My thoughts so far are to use a frame mount aero bottle for races and swap it for a conventional bottle holder for training.  For Sprint and Oly races I dont think I will need any more than 1 bottle on the bike.  Once I start doing longer rides outside again (Its winter here and I am on the trainer now), I may add a rear holder, but just use it for training rides.

While I havent tried one yet, I am not sure I want a bottle mounted on the aero bars.  Not sure I want the straw in my face and not sure if I have enough room with my computer (705) also mounted on the aero bars.  I have also heard some say the straw impacts aero dynamics.

I really like my Profile Designs aero drink bottle.  Having the water literally right in front of you is super conveinent and it's relatively easy to fill on the move.  I also have a seat tube mounted water bottle, but have found myself running a little bit dry on my longer rides. 

I have been putting some thought into running both the Profile Design and the Inviscid Design Speedfil system.  The Speedfil is almost like a CamelBak style hose that feeds off a 40 oz reservoir that can attach to your seat tube or down tube.  Thought it might be cool to have 62 oz of two different fluids available. 

Only problem, I'm not sure I want to bring along 4 pounds of water though...

If training and taking your own fluid for a 2+ hr ride, a 2 bottle rear wing works great.
in a sprint or oly race, you're proly only going to need 1 bottle 2 at the most, a rear wing works fine
HIM or IM will undoubtedly have bottle exchanges somewhere on the course, cary 1 or 2 bottles, a rear wing works fine

Can you tell I use a rear wing?
Profile seat post mounted one on my old Cervelo, now a seat rail mounted PD one on my new bike.

Tried a budy's aero bottle (between the bars) and the straw p!ssed me off.

I'll be picking up my new B14 on Monday.  I plan to use just a Torpedo aerobar mount for short tri's.  For training I'll just be adding a mount on the frame as well.  That should be enough for me.  I had the rear mount on my past bike and it was an effort to keep reaching back for hydration.  Good luck

You should cut the straw down so you have to dip your head slightly to take a drink.  Then it's not in your way.  As for the computer, I have a Joule 2.0 mounted in front of my bottle, still leaving room for my hands in the proper position.  It's a close fit but it works.


Negligible.  It's airflow that's going to hit the parachute (you) anyhow.

I disagree with the fact that it is negligible; it may not be something that the OP is worried about but not something to be dismissed out of hand.

A cylinder, especially one that meets undisturbed air, is terrible from the standpoint of aerodynamics.  The bottles themselves are fairly aerodynamic but the straws most definitely are not. 



Shane

Once again though, if you take the objects in that drawing and put a rider behind them, the importance of the airflow around them is much, much less.

Consider if you're nitpicking every little thing for a time trial, you're probably removing that entire bottle anyways.  In a HIM or IM, you could assemble a laundry list of aero "problem areas", both equipment and rider position, that'd have more impact than a straw.

How does putting a rider behind the cylinder negate the impact of the aerodynamics of the cylinder?  Of course the cyclist is the largest component of the aerodynamic drag but if I can easily remove something that has a negative impact on aerodynamics, then I am going to do it. 



Again, there are clearly other concerns, but why would you ignore something that can easily be addressed?  In the same way that I am not going to race on slow tires or tubes, regardless of distance, I am not going use equipment that has a detrimental impact on aerodynamics when there is a viable alternative.

Shane

A brief observation about the straw in an aerobar mounted hydration system.

I have a Bontrager Aero Race Pack.  It's a single reservoir aero bottle with an integrated straw.  When I first mounted it on my bike I noticed that the straw flopped over to the left.  I thought to myself "I'm gonna have to change that".  After the first use I noticed it was an advantage because it didn't get in my way.  The lesson here is don't adjust or cut the straw until you've used it a few times.  

I also have an XLAB Carbon Wing with Gorilla Cages.  I use these most of the time and have no other cages/bottles on my frame.  The Bontrager Pack is just for HIM's and my first IM in November.