The Camelback bottle I’m wearing is working really well, but I need to be able to carry more water on longer rides, and I’d rather not wear the water belt on shorter ones. While wandering around the Internet, I read about the Bar-ista, made by Portland Design Works.

Leaving aside the whole question of why you’d ride a bicycle with a cup of coffee (rather than a closed mug) on your handlebars, it occurred to me that I might be able to make this work for my Brompton. It’s simple, sleek, and all-metal (!). So I bought one.
When it arrived, I realized that, to use it on a Brompton, I would have to unscrew the loop, and re-install the clamp upside down. Then I mounted it on Basil’s handlebars — making sure, of course, to cut a piece of inner tube to put between the clamp and his handlebars.

The supplied clamp screw was too short to allow the clamp to go around my Brompton’s bar, so I found a longer one at a hardware store, along with the wing nut I’d need so that I could swivel the holder out of the way when folding Basil.
My Brompton has the M bars, so I installed the holder at the bottom, near the stem.

I’d read that people complained that coffee cups could fall through the Bar-ista, so I added a mesh bag that is part of my travel gear. (It’s ostensible purpose is to allow me to carry liquids attached to my suitcase handle. It works, too, but Basil’s need is greater.) The mesh pouch is attached by cable ties.

I had to place the cup holder carefully, so that using the wing nut would not interfere with my Brompton’s cables. I do have to be dexterous, but it’s amazingly easy to flip the holder up so that it aligns with the handlebars.

The impact on the sleekness of Basil’s fold is almost non-existent.

The mesh pouch tucks into the ring. It tends to stay in place, but even if it didn’t, it’s small enough that it wouldn’t matter if it flipped out when Basil is folded.

If I do choose to leave the holder flipped out when my Brompton is folded, I can put my water bottle back into the ring, which means I don’t have to carry it separately when lifting Basil. This is especially nice when boarding trains.

A skinny water bottle is required. This Sigg fits perfectly, and is easy to lift in and out while I’m riding. However, the cable ties were not kind to that lovely matte finish on the black Sigg, so I bought an unfinished stainless Sigg to use instead; it won’t matter if its surface gets dinged and scratched a bit. (The second Sigg is in the photo above.)

As of this writing, I’ve only tried this kit on a short run; a longer test is in the works. But so far, I’m very pleased.

I’ve also discovered that the mesh pocket, when not in use, behaves like a wind sock sometimes, which is quite amusing (but doesn’t slow me down a bit.)