After the day of the dead ride and a couple of 40 min rides I decided a convenient water solution was required.
This Japanese system is intended for hybrid bikes and dahons for a single bottle. For very long rides* I can carry a spare in the saddlebag. I saw this on another Brompton blog and found it at SJS cycles.
* very long in Brampton terms. I've asked Santa for a running/mountain biking hydration backpack so I can do long runs/days out/4 hour rides without stopping.