Why am I stupid?! : ) - Hydro bladder in 2L, narrow top tube bag for high vol. aero sipping?

I’m hoping one of you fine ppl can help me understand why this is such a terrible idea! :laughing:

I have never seen this done, so there must be a reason!!

Doing a longer [for me] Swim - Bike; 58km, in 25 - 40 C super humid weather. I will almost certainly kill 1.5 - 2L… and finish super thristy…expected bike time 2 - 3 hrs. Unknown. Dead-flat course. No wind ? 27 - 38 km/h. Headwind? 12 km/h…backwards!!! :laughing:

I want to be able to aero-sip from a bite tube, mounted to my TT bars. One of the Profile Designs or other Aero / TT mounted bottles around 500 - 900 mL just won’t cut it.

There are systems for sale that sit at your bottom bracket and the tube runs up, but they are:

1 - Very fixed, and won’t fit lots of frames, mine included.

2 - One million dollars. I figure I can MacGyver one together in a narrow, low profile top tube bag, with a Platypus bladder & bite valve for about $30 - 60, all-in.

All constructive ideas & input… [and gentle insults to this terrible idea!!] … are appreciated!!


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consider wearing a a camelback on your chest? under your jersey. Has aero advantages as well.

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No time to search & link, but Camelbak already sells one version. And IIRC, it was last year where someone notable did Unbound and got lots of press for their DIY top tube hydration approach. Definitely been done in other examples to be found.


@MikeMckinney that is a decent idea, and I appreciate it! I think, just for me, I’d find it uncomfortable, and while I agree; ya, filling in that “chest - arms gap” would help out, I think it would just be a sweaty disgusting mess… like, I’ll take the aero hit, for the extra ventilation & cooling!! :slight_smile:

Yeah that makes sense. Alternative, big frame bag that is used for bike packing, stick a bladder in there and use some gorilla tape/zip ties to get the hose up by your hands. Some Triathlete use earth magnets on the aero bars to keep the hose tidy.

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@mcneese.chad cool, thanks! Appreciate knowing it’s been done successfully, and I’m not just out of my gourd! :laughing: Will probably start working on slapping one together then.

Actually I think wearing a hydration pack has showed aero benefits. The hump is more aero than a flat back.

Only 3 watts but, at least, no penalty.


Still searching for the DIY, but here is the Camelbak.


ETA: I guess it was longer ago than I realized (2021).



I’ve tried this with a hydration bladder in a frame bag, and I was only able to drink 2/3 of the mix - I couldn’t get the rest out.

Gravity is the reason. You need a lot of pressure to pull water up 3-4 feet to your head from a frame bag near the bottom bracket.

This isn’t as much of an issue with a hydration pack, for two reasons:

  1. It’s on your back, much higher up
  2. The bags are all designed to compress the bladder as it empties, ensuring there’s still enough pressure to get the water out.

I bet a lot of the expensive systems have some way to maintain pressure on the hydration bladder as it’s emptying.

If you put it in an under-the-top-tube bag, that might have a better chance of working…


Orr Cycling sells a frame hydration pack that still leaves room for small bottles (probably want side-loading cages, though). 1.5 L


This was my set up for gravel, you have to test it out but it worked for me. I wouldn’t say it’s aero but it’s better than a backpack, imo. Lately, for gravel races I use the same bag but put a liter bottle inside. Way faster at check points to refill water bottles than a hydration backpack, again imo.


@mcneese.chad @rkoswald @ChefAcB thanks a ton all, really appreciate all the info and direct product recommendations!! :slightly_smiling_face:

Def trying to stick to the “ghetto” route; super low cost. That Platy Hoser was exactly what I had in mind, in a 2L; had one in the past for hiking. Then just jam that into a “low profile” / slim, dirt cheap top tube bag. Just have never seen it done, and thought there was a reason I wasn’t thinking of why it was a bad idea.

@wake damn good point about the force it would take to pull it up from the bottom bracket!!! That possibility cancelled. Top tube would be way easier…

Thanks a ton, again! I will post what I end up putting together, links, costs, and how well I find it works.

No matter what, I figure it’s gotta be way more aero than me flailing around like a drunken gorilla pulling my bottles out of the frame cage, drinking & replacing!!! :laughing:


I haven’t watched this yet, but bladder setup on frame again for UG this year.


Do it!

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Wondering how something like the crank tank 3 compares in feel vs the Frame bag style. About 100g heavier than the Camelbak Mule but would think that weight would feel a lot nicer being that low on the frame. https://adventurehydration.com/product/cranktank-3/

This company popped up on an instagram ad

Hey all. System is ready to rock & ride tested.

Thanks for the above product suggestions. I’m sure they’re awesome quality, etc.

As w all things bike, the prices are just ridiculous. $ 180 CA for a bag, some velcro, and a tube. :roll_eyes: We get so taken advantage of, it’s nuts.

So I just made one myself. Just had to find the right fitting bag & bladder combo.

I nailed one down for $ 88 CA all-in.

Not currently pictured below is the hose, which exits the bag zip on right side front, and is tightly routed up onto my aero bar, right below my left wrist. I don’t move my back or head at all to drink. Grab, sip, replace.

Awesomely, Platypus intends the Hoser [LOL…] to be a hydro bladder inside a backpack, so they include a strap clip. I cut the strap-clippy parts off the hose clip, and it works a dream electrical taped to the aero bar.

I have a bunch of ROCKBROS gear, incl some really good articulated knee insulated riding pants. So far, what I’ve bought has been equal quality to the “bike brands” ; mini top tube phone bag, etc, at 1/4 the cost.

The bag won’t accept the full 3L capacity of the Hoser, but does take a full 2.5L… perfect. The width is perfect; very thin, no knee contact issues. [Measurements and/or pics w bladder full if requested, no prob. (The hydro bladder full… not mine…)]

Shockingly, I do not have a wind tunnel in my 600 sq ft apartment, but I feel 100% sure the bag is far more aero than my bottle. Esp. bc my seat post is soooo aero, w the tire in-set, etc. The bottle was really messing that up.

The extra wgt on the top tube isn’t a problem for low speed cornering. You can notice it, but it’s no biggie. [A less confident rider may find it feels more tippy; it is noticeable.]

Really looking forward to blasting by the bottle drop @ the 40km mark! :sunglasses:

Any Q’s, LMK.




IDK if anyone is still watching this junk or gives a crap.

But it freakin’ worked. The race was yest. I passed 8 ppl at the bottle swap, bc I didn’t need it. While others were sitting up and drinking and slowing down, I was drinking in full aero. One small wrist movement.

Also, I put about 0.75 L in it night before and froze it, and 2 L in a bottle in the fridge to cool it to 2-5 C. In AM, dropped the ice on the ground to crack it up, poured in the 4 C water, off we go.

28 C + HUM = 32-35 ish. Still at halfway, around 2-3 hrs after out of freezer, water was cool-ish. V v v nice feeling vs hot water….which came later :roll_eyes:

Anyways. Thanks for your help and support.

I finished 17 s & change off a guy who qualified for worlds in Spain. He was on a billion dollar bike w a disc. I was on the Frankensteed. So I’m ok w that.


Hell yeah, awesome news!!! :metal:

Any takeaways besides “it worked”? Did you have any water left in the bladder & have you estimated how much further it would’ve taken you? Do you have any sort of warning when it approaches empty? With a plastic bottle you can see the level & with a metal bottle it at least feels lighter. It’s just that I would not like to be 20km from the next town or control point & suddenly start sucking air.

And how did you carry carbs on the ride? Bottle? Gels? And where?

So yeah I’ve been watching. :popcorn: Contemplating such strategies to speed up my audax rides. My seat tube bottle cage mount is very low so it’s plausible I could fit a standard cage there with a 500mL with 400g of carbs in it, but personally I’d prefer that one between or under the aero sticks. There are mounts for positioning a bottle between the sticks.

So for 88 bucks & a little bit of hunting around you optimised better than people who spent thousands of dollars & maybe thousands of hours. :brain: Love this!

Reminds me of an old & funny TV ad here (which I haven’t been able to find again :slightly_frowning_face:) of a car blowing past a fuel station, leaving the owners of the station very surprised.

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@roleypup thanks very much for the kind words. :slight_smile:

Yeah, I was super happy about how it worked out. When you come up w these cockamamie ideas, often there’s a damn good reason other ppl aren’t doing it; something you’re failing to predict, why it won’t work.

This time it worked smashingly.

The only one stumble was: Holds 2.5L, and at about km 46 of 55, it sucked dry. It was 28 C + hum = about 34 - 36 C, so I was sucking through it, and thought it was dead. Turns out it actually folded weird as it collapsed, and I had about 0.5L left.

So I think I am going to super glue or duct tape some super strong plastic chop sticks to the water bladder, to hold it straight as it collapses, and prevent side-folding.

The carry bag is flexible, so you can give it a squeeze and lift and get a feel for roughly how much is left in it…+/- 200 ish mLs.

On the carbs: I don’t chat nutrition w ppl bc I use a different strategy, and ppl don’t like it and just get angry at me, keep telling me I will die, can’t perform at or above threshold, etc. But I keep doing stuff like as pictured below, so it seems to be working for me. Super high fat, low carb, and adequate protein. I don’t fuel on the bike. Last fuel before the race was super high fat dinner the night before. I keep doing things like below, and this was after a 2k swim; 39 mins @ maxxx swim pace.

Hardly shows “inability to perform at or above threshold.”, etc.

So for now, it’s working, and I’ll stick with it! :slight_smile: But don’t care to discuss pros / cons, neg health effects, etc etc, nor do I want to convince others to try it. Everyone hates it; so… OK then, don’t try it! Easy! :slight_smile:

But I rly don’t need anyone trying to convince me not to use this strategy! :slight_smile:

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