Tuesday, July 12, 2011

How To Carry Water Bottles On The Bike For Triathlon

The bike leg of a triathlon is a time trial in every sense except one. While in both disciplines the rider rides solo against the wind and the clock, trying to maximize every aerodynamic advantage, in a triathlon the race doesn't stop at the end of the bike leg. This imposes upon the triathlete the requirement of bringing nutrition and a flat kit (Time trialists don't need a flat kit as, if they puncture, they either: a) wait impatiently for the team mechanic to swap out the wheel, or b) swear loudly in a European language, gesticulate wildly, and quit the race). Having to bring luggage along in a triathlon is complicated, however, as less is more when it comes to cluttering one's bike and maintaining optimal aerodynamics.


The answer to this dilemma, I have found, is decidedly simple. One only needs a front-mounted hydration system, an aerobottle on the main triangle, and a conveniently hidden flat kit (eg. tucked away in the bento box or taped to the saddle rails). The general consensus is that in races from Sprint to Ironman, you don't need to carry more than two bottles on your frame. For an Ironman, simply refill your front-mounted bottle (or aero hydration system) with what's provided on course and keep a concentrated nutrition mixture (*cough* Infinit *cough*) in the aerobottle.

In the above picture, Chris Lieto has tucked away a third bottle tightly against the saddle rails. Notice how the bottle's orientation is nearly parallel to the ground. The traditional behind the seat racks, for example Profile Design's Aqua Rack, have the bottles situated upright. This disrupts the smooth river of air flowing down your back and acts almost like towing along a tiny parachute. Lieto's arrangement for this third bottle is actually how I carry my flat kit (described below). Previously I had taped it there, but removing the tape took longer than it would take me to fix a flat. Having everything tucked in a bottle works well for me.

The only question you really need to ask yourself is do you want to have a horizontal-mounted, standard water bottle, or, an aerodynamic-bottle w/straw up front. Each as its own merits and drawbacks.

Chris McCormack  proselytized many by rocking the horizontal-mounted standard bottle on his way to victory at Kona 2010. You can see that the flat front of the bottle can be easily exposed to the wind, though. 


The beauty of the horizontal-mounted standard bottle lies in its simplicity. A cheap bottle cage, some zip ties, and you're good to go. Refilling on the course is as easy as swapping out bottles, no period of slowly rolling along and refilling required (as is the case with the 'strawed' variety). The main detriment is that, unless concealed by your forearms, you're pushing a flat disk into the wind. Apparently it's not as detrimental as you would think- see the graph posted below- and it's important to note that his method has currently taken off like wildfire among the Pros. 

I like Torhans' product for its very thoughtful design. From it's true-aero shape (as opposed to the rather bulbous, relatively-aero shapes of it's competitors) and NACA-profiled straw. 


The aerobottle with straw option is also enticing. These are aerodynamic bottles which you drink from through a straw and are refilled on-the-go in a race. Not all of them are created equal, however, and I would strongly endorse the new Torhans system. Trisports.com did a thorough review of the current options here and it's definitely worth a look if you're interested. These systems are criticized for having a straw constantly flag-poling about in the wind, so it's important to keep your straw as short as possible (for example, you may lose around 1 Watt of power for every inch or so of straw that is exposed). Although, if you have a road bike or a triathlon bike with a round headtube, the aerodynamic shape of the bottle will hit the wind first, instead of your less-aerodynamic headtube, and provide a nice, aero benefit.

Here is an interesting graph courtesy of Torhans' wind-tunnel testing (click on the image to enlarge) that compares the drag (the lower, the better) of different systems currently available:



I was debating the merits of Torhans vs. the horizontal-mounted standard bottle myself when I switched my bike computer over from my road bike to my tri bike. The decision became a lot easier when I looked at my new front end.
With my silver bike-computer sticking up into the wind, I knew that the horizontal-mounted aero bottle could now conceal both the faceplate of my stem and the computer itself, partially negating the aerodynamic disadvantage of this system. So I literally 'ran' errands and picked up a pack of twenty 8in black zip ties for 77 cents and relocated my seat-tube mounted bottle cage (which I'd initially picked knowing that I would likely swing this way. It's stiff, but adjustable by bending and allows for easy access to the bottle while in the aero position). 

Here is a shot of my bike before adding the bottle up front. 

And here it is with the cage zip-tied to the aerobars. I used eight of the thin zip ties, two at each spot. I simply looped them through the holes in the bottle cage intended for the bolts to mount it to the frame. 

And here it is with a standard, large water bottle in the cage. Though it looks like a tight fit, the bottle is extremely easy to remove and replace. 


And here with a shorter water bottle. 

The view straight on. Notice how the bottle has eclipsed the faceplate of the stem and my bike computer perfectly. No additional tinkering required, it just naturally landed in this position. The whole process took just minutes, making products like this $40 "Torpedo Mount" from XLAB seem shameful and ridiculous. 
No offence intended if you have one.


Having successfully mounted my front bottle, the next step would be to use an aerobottle mounted on the downtube for my secondary bottle filled with concentrated Infinit (for longer races such as my upcoming half-iron or next year's IM CdA). But until Christmas rolls around, I will be using the behind-the-seat bottle holder that I purchased and mounted in reverse, to keep my second bottle tucked up behind the saddle Lieto-style. This bottle will either hold my flat kit or, as mentioned, function as my second hydration bottle if needed in a longer race. 

First I purchased the Minoura Single-cage rear holder through Speedy Reedy. They were, per the usual, extremely helpful, and the part was soon waiting in the shop. Using a product in place of possibly using zip ties is somewhat hypocritical given my critique of the XLab system, but I hadn't yet fiddled with zip ties to see if they would work. The stiff Minoura holder is a convenient solution and quite affordable anyway at $10. 

You can't tell from these photos, but the Minoura holder has some very impressive machining (i.e. it looks nice) and is very sturdy. It is, as all things should be, matte black. 

Here it is mounted to the rails of the saddle. The product is intended to be mounted in the opposite direction (such that the cage holder would be parallel to the seat-post), but I trickily flipped it to keep it tucked away from the wind. 

Though not very aesthetically appealing, the standard, metal bottle cage that I elected to use is faithful (it won't snap like the over-priced, under-performing Karbon Kage that I had from Profile Design), and can be bent slightly to keep a tight hold on the bottle. 

Now with a water bottle. 

Another perspective...

The frontal profile of the bottle+cage is fairly minimal, I'm quite pleased with how it worked out. Also, when and if I get an aerobottle for the frame, my pump from Topeak can be mounted to the bottle-cage holder and my flat kit affixed to it in a ziploc, making the whole assembly both very secure and more aerodynamic than is even seen here. 


There you have it! My thoughts on how to carry nutrition and a flat-kit during a triathlon. This system will work beautifully for training and on race-day without breaking the bank. Or even a $20 bill. But of course the most important thing is finding a system that works well for you, I simply wanted to share what I ended up with. 














8 comments:

  1. I personally use the speedfil - http://www.invisciddesign.com/ - which fills up the space in the frame. It's awesome, and you don't have to shift your tt position to drink... very aero!

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  3. Speedfill sucks. Take a look at the drag chart in this post

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  4. Great article. I have an Adamo saddle and used the 'zip tie' solution for the rear cage. I used an Xlab gorilla cage and so far so good. BTW I used the Xlab solution for the torpedo mount on the front and I'm not offended ;-) I also use a Dark Speed Works 'bento' style box on my top tube to hold my tubes and puncture kit. I *think* it is pretty aero as it is hidden behind my front cockpit but who knows!

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  5. I have a water bottle cage mounted between my aerobars for oly distance tri's but I am moving up to the half iron distance. I am toying with the idea of a straw system like torhans so I can just have that and one bottle of concentrate (otherwise I would carry 3 -20 ounce bottles). Just debating between the extra weight of the fluid versus having to dump water from the aid stations and concentrate into a straw system on the go.

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  6. Hi Sharon, those are both two great solutions. To get around carrying the weight of extra fluid, at my most recent race (IM CdA), I carried an aerobar-mounted horizontal bottle and an extra bottle of IM Perform as a backup. My plan was to drink 30oz of Perform per hour, and each bottle was 20oz. With aid stations every 30-40min, I didn't need more than one bottle at any point, so I even stopped carrying the extra further along in the race for faster intervals but it never hurts to have a spare. The Torhans system is really well-designed; I don't think you can go wrong either way!

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  7. Great post and explanations with pictures!

    You have to be careful with the drag graph since it clearly says it's an 'average' at all yaw angles. It's not clear if it's a simple average or a 'weighted' average (which would be more real-world - i.e. rarely do you encounter 'effective' yaw angles (wind from forward movement combined with ambient wind) greater than 20 degrees.

    Nit-picky-ness aside - the post was great!! Thanks!!

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