In my almost 3 years of vintage bike hunting I finally come across a mid 90s mtb with all Shimano XT 8sp stuff and a downtube aero water cage. Thereīs also a saddle aero cage but again no bottle. I donīt even know where to find aero bottles for them but still very interesting gimmicky accessories.

Some of the Japanese aero bottles from the 80's look really "gimmicky to me with their very exaggerated "Spaceship" - like, delta shapes (usually molded in silver plastic) that did not look easy to grip and handle and especially their conical and pointed nozzles that look like they could poke your eye out. IIRC, one of these was the one made by OGK.

Waterbottle shape is a standard. Lose one of those aero bottles, might as well throw away the cage as well.

Here's a Carnevale with a Campy bottle from a recent Pasadena ride.

I think it's funny how, in the 1980s, several makers were trying to reinvent the bottle cage. Cannondale had one with velcro. I think it was Rhode Gear had a unique dovetail mount. More than one had versions of aero bottles. Now 30 years later, we are pretty much back to where we started.

This one had required drinking through an X-shaped cut in the rubber top. Yes, it was creepy.

I have two of those Campy bottles and cages.
They are not good bottles, and they look kind of blocky on the bike.

Maybe they're aero. At my speed, there's really no such thing.

I think that's one of those get-around-the rules kind of ideas.

TECH INSPECTOR: That's an aero faring.

RIDER: No, it's a bidon; Look, you can drink out of it!

TECH:

I suspect that, far and away, the item on my bikes with the most aerodynamic drag is... me. Not sure I have ever selected a bike part based aerodynamic features.

Yeah, I like the traditional diameter (and length) bottles for ease of use. Wait a minute, I did put an aero bottle on my wife's old bike, since stolen.

Aero and mountain bike don't seem to get along comfortably. Maybe the Shimano engineer was a Jetson's fan.

Aero bottles, like everything aero, matters ... after you've aero'd everything else possible. It might make slightly more difference than shaving our legs. For a shorter time trial the most aero bottle might be none at all, at least on an aero frame.

Biggest improvement in my average speed came from getting lower more consistently on rides, especially on windy days. But it took a lot of physical therapy to be able to get to that point. If I'm recalling correctly from some published wind tunnel testing results, the next most significant aero factors come from snug fitting apparel and an aero helmet. I think shoe covers were significant too.

Kinda makes me wonder why those fat, hollow tube carbon frame bikes don't include an option to use the downtube as a water reservoir, complete with aero straw running through the tubes and headset.

But with cable-free electronic shifting now, maybe the next big thing is to teleport water from the downtube reservoir, no straw needed.

I have three or four of these if there's a need......

2-3 in boxes.

Just sayin.

Any talk of aero in regards to me on a bike is pretty much useless. Think SpongeBob aero.

I think a couple of my wheelsets get an aero advantage above 19mph....um, still useless.

Like @gomango, I have a couple of those Campy jobs. Seemed like a good idea at the time....

I might be able to live with the Campy bottle, just to match up to my pate 80's gruppos on two of my Italian bikes...... but I think it's the Gigantor looking size of the Campy aero bottles that is keeping me from getting to like them enough, to install them in my C&V bikes....