Am I completely insane to run BTA hydration on my gravel set up?


My A-Race next year is Gravel Worlds. For those that don’t know, Gravel Worlds is 150 mile gravel race around Lincoln, NE. The course changes every year, but it’s always involves non-stop rolling hills. The course always has roughly 10,000 ft of total climbing every year, but it’s broken up in endless 50-100 vertical feet chunks. The difference in elevation between the highest and lowest points on the course will be about 300 feet.

The gravel is pea sized and, if you can find the tire tracks, its not really that far off from asphalt:

My primary goal is sub-8 hours…which equates to about 18-19 mph average, but real speed on the course is probably slightly faster due to time off the bike. A lot of this will depend, of course, on the conditions of the day. However, at a moving speed close to 20mph, I think aerodynamics will still matter A LOT–according to the Flo guys, the difference between a Open Pro and their Flo 60 is almost 9 minutes at 20 MPH over an Ironman bike course.

There is no outside support permitted (other than neutral support at the checkpoints). Two mandatory checkpoints and other optional checkpoints along the way. I’d like to be able to carry enough water to only need to stop at the mandatory checkpoints.

Pretty much everyone will be using aero bars and I will use them too. I expect at some point I’ll get spit out the back of the lead group and getting stuck out in the wind for 50 miles by yourself on the plains is no fun for anyone and much less so without aero bars.

So here are my thoughts:

  1. It’s pretty well established that, in the time trial position, having hydration between your arms is faster than pretty much any alternative. I have no idea if this holds true in a normal road bike position.
  2. I’d like to have enough fluid on board for 3 hours total per checkpoint. 24oz/hr puts the total at 72oz. That’s kind of cutting it close, but there should be enough gas stations/optional checkpoints to refill if I get in a jam and need more water.
  3. Based on this, my hydration setup could then look like one of the following:
    a. DREAM AERO SETUP: 24 oz BTA + 2 24oz bottles behind the seat (lots of testing would be need to ensure I’m not ejecting bottles left and right)
    b. 24 oz BTA + 50 oz USWE hydration pack.
    c. 24 oz BTA + 2 24 oz bottles in frame

I would really love to get some data on (a) how much of my time needs to actually be spent in the aero bars to make the BTA “worth it” and (b) what is faster between the hydration pack and bottles in frame options. I’m also wondering what kind of impact on handling a BTA set up would have.

I’m planning on picking off a lot of the other low-hanging fruit as well: aero road helmet, skin suit, deep-ish section wheels, fast tubeless tires, trainerroad subscription. I might even rock shoe covers if its not too hot :joy:

I realize that doing this will make me look like a HUGE dork, but I don’t really care as long as its fast.

Is there anything I’m seriously overlooking here?


FYI, since nobody said I shouldn’t do this I’m going to go for it and see what happens.

I have a couple of tune up races before my A race so I’ll give it a go and can ditch it if it doesn’t work.


Seems like a fine idea to me. I say use it if it is within the rules.


I appreciate the “Other Chad” stamp of approval. I’ll make sure to report my findings.


For whatever my opinion is worth… :stuck_out_tongue:

If possible, I’d love to hear about your experience. I am planning a gravel focus this season, and hearing about these larger events is fun for me since I’m a bit far from those ones.


I would be happy to do so. I will probably revisit this thread once I get my set up dialed in.

I would like to find some time next spring do some chung method aero testing on the various setups discussed above.


I don’t have data, but my experience is that if I have aerobars and a BTA bottle, but I only use it some of the time… I am a little faster than if I had neither and couldn’t ride in aero at all. So you probably aren’t costing yourself time by having it and not using it.

Drinking from a BTA setup while you’re up on the hoods is another matter. It doesn’t work very well. As for handling, I have never noticed a difference with a bottle there vs. not.

I know people in the triathlon world who have tried hydration packs, and they seem to be generally uncomfortable and warm up the liquid faster. The scheme the TR crew used at Leadville, with a support team providing fresh cold hydration packs, is probably the best way to make them work for the long haul.

For bottles behind the seat, look to tridorks for what works: XLAB Gorilla Cage and TriRig Kappa cages.

However, I sort of feel like the relative aero cost of bottles on the down tube / seat tube are not that big a deal. They aren’t ideal, maybe, but they aren’t going to make nearly as big a difference as how much time you spend in an aero position, whether you have to soft pedal while digging a bottle out from behind your saddle, how much time you lose to ejecting bottles behind you…


These are some good points. If I can get the BTA squared away then I can play around with my options. I think the aero testing will be crucial to make an educated decision on whether the time savings are worth it. Additionally, I’ll have a few warm up races to dial all of this stuff in. I’d rather eject a bottle at one of those races and know that it won’t work.


I did DK200 this past year with clip-on aero bars and have some experience that might carry over. It sounds like DK has much rougher gravel than your event, so YMMV. DK has 3 rest stops, roughly every 50 miles, and riders are self-supported so one needs to carry enough water for ~3.5-4 hrs between refills. It also can be VERY windy and VERY hot. This past year was both: >100F for several hours mid-day, and 25+ mph block headwind for most of the second hundred miles.

Riders frequently struggle with dehydration at this event and I really wanted to avoid this. I’m a heavy sweater, so I carried 2@ 1 liter bottles of Skratch, 1@ 750ml bottle of a different flavor Skratch, a nicely fitted frame pack with a 2.5 liter bladder filled with water and a hose with bite valve run up BTA. So, kind of like what you’re thinking about, but turned up to 11.

In a nutshell: this was a great way to go. Hydration packs are hot and not aero. The course was strewn with literally hundreds of bottles that had been ejected from saddle-mounted holders (with the bonus being that their owners didn’t know they suddenly had no water until miles later when they went to take a drink, uh-oh). I spent a ton of time in my aero bars and being able to sip water without breaking position was huge while clawing upwind.

As I said, I understand your event is a bit different so you may not need to go to the extremes that I did. My only concern, though, is that you may not be carrying enough hydration on the bike if you “only” have just over 2l and you’re trying to go 3 hours at a stretch, at race pace, possibly in some serious heat. Maybe that would be sufficient for a single 3 hour leg, but I’d be concerned that your third leg could find you dehydrated. My experience at DK was that the first 100 miles was pretty easy and then people (myself included) started to blow up left and right–mostly, I suspect, from dehydration. I’ve since measured my sweat rate and it can exceed 2l/hour, which blew my mind. So even if I’m drinking 1l/hr, which is hard to do, I’m still running a deficit of 1l/hr or more. No prob for a few hours but for a very long event… watch out.

Sorry, I hope I don’t sound too mansplain-y here :wink: It’s my longwinded way of saying 1) Yes, BTA hydration is smart, and 2) If possible, I think it’s better to approach it by measuring what your body needs rather than what’s convenient to carry. I hope you’ll update here in the forum–I’ve yet to settle on a hydration approach for ultra events that I’m completely confident in.


Thank you for sharing your experiences. I’m also encouraged to hear that BTA worked for you.

I would like to point a couple things out though.

  1. This race is on home turf, so I’m definitely aware of the demands that the heat could potentially put on me. Weather in this part of the country is a real crap shoot, though. It could be 100F with unbelievable humidity or it could just as easily be 70F. I’ll really need to be prepared for everything.

  2. My hypothetical hydration set ups listed above were based on the maximum volume of fluid I can take down in an hour. I believe the upper limit of liquid the stomach can process in a hour is about 800ml. I just can’t imagine drinking more than 24oz of fluid in an hour and still being able to eat what I’ll need to eat over the course of the day. I also religiously weigh myself before and after every ride so I have a pretty good handle on that front.

I’ll probably go with Skratch to help with maximize absorption and keep my electrolytes somewhat in check.

Unfortunately, you’re never going to be able to completely replace the fluid you lose, especially for a big endurance event like this. I think a big key is to focus on your hydration before the event. I think between carb loading and taking in some hyper hydration drinks, I should hopefully be carrying a lot more water weight than normal going into race day.


Roger that. Ultra events like this are about so much more than “just” riding your bike, eh? Looking forward to seeing your final setup and hearing about your event. Good luck!


I think it’s akin to an Ironman. It’s an eating and drinking contest more than anything.