https://www.xlab-usa.com/products/single-rear-hydration.html

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Washed up footy player turned Triathlete.

I’ve always felt it was the worst possible place for a bottle.

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Dan Empfield
aka Slowman

Care to elaborate SM?

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Randy Christofferson(http://www.rcmioga.blogspot.com

Insert Doubt. Erase Hope. Crush Dreams.

Were you going to attach a photo?

Slowman, I really think that *depends*. I have tried all sorts of configurations and still lobe my behind the seat bottles.

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David
* Ironman for Life! (Blog) * IM Everyday Hero Video * Daggett Shuler Law *
Disclaimer: I have personal and professional relationships with many athletes, vendors, and organizations in the triathlon world.

If you buy the new Shiv Disc, they have fitted a convenient tail fin for you to rest it on. Assuming you're taller than about 5'8.

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29 years and counting

as you noted with the race this past weekend, lucy charles lost her chance at her bottle near the bike turnaround. it's a hard place to get bottles in and out. it's time consuming. you must slow down. bottles eject. they shouldn't. they won't with an xlab gorilla cage. but many do, because of a bad angle or a bad cage. and then others run over them and crash. it's not aerodynamic. if you try to hike your leg over the seat to get on your bike you catch your leg on the bottle.

other than that, it's a great place for a bottle. certainly you can mitigate the problem using best practices. but, are you kidding? trying to get rank and file triathletes to find and read best practices on anything? therefore, i just don't find it a great place for bottles. there are much better solutions in my opinion.

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Dan Empfield
aka Slowman

I'm assuming you're having issues with an ISM style saddle with the "transition hook", which seems to be the least compatible saddle for rear hydration. Giant's Trinity Water Bottle Cage Mount works pretty well in this case. Its what I'm using on my bike.

https://www.giant-bicycles.com/int/trinity-water-bottle-cage-mount

Gotcha. Thanks.

I was worried about a possible aero penalty. I have BTA, which I refill from a bottle that I store back there from time to time. Mine don’t eject. I lose it before transition at the final aid station. I don’t have a problem at dismount.

Is it worse than on the down or seat tubes?

rc

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Randy Christofferson(http://www.rcmioga.blogspot.com

Insert Doubt. Erase Hope. Crush Dreams.

There are compromises in every hydration solution. My own solution is based on maximizing aerodynamics and the practicality of using on-course nutrition. I use one bottle behind the seat and one BTA bottle in half iron races or in an Olympic hot enough to justify two bottles. I am not currently doing the IM distance but I would use the same setup. My own field testing shows a measurable aero improvement over even one downtube bottle with this setup. The rear bottle uses a gorilla cage and is tucked right behind the seat and angled steeply towards the rear, it adds no frontal area. I have no problem swinging my leg over it to mount and dismount. I only drink out of the front bottle, not the rear, the rear is for storage. When I've used up the front bottle, I swap the front and the rear. This takes only a few seconds and I try to do it on a false flat where the penalty for sitting up is minimal. I can drink out of the front bottle while staying in the aero position with no problem, jackmott had a video demonstrating this quite a while ago. Then when the second bottle is used up, I discard it at the next aid station and grab a bottle. I've never used more than 3 bottles in a half iron so the front to rear swap is only done once.

In contrast, refilling the fancy front drinking systems that everyone uses would require sitting up twice to refill on the fly, which always seemed to me a sketchy thing to be doing on crowded courses, and takes longer than my one front-to-rear swap, meaning more time out of aero. My wife uses these and both of the systems she's used have required duct tape to prevent sports drink from splashing all over the bike.

I would not use two bottles behind the seat as I believe it's much harder to make two bottles aero than one, and I would not use a bottle behind the seat for everyday drinking, unless it was a special mix I only needed to drink every now and then. I gave up on concentrated drink mixes due to stomach issues but if I was using such a mix, I'd either use one behind the seat for the high calorie and swap the front at aid stations, or I'd use an aero bottle on the downtube.

Search the tririg site for the Andy Potts page. It shows you how to drill a hole in the back of your ism and zip tie a cage in place.