Power To The Pedal

Competition Details

Bladderless bite-valve hydration system for cycling

by Alison Chaiken

y bicycle water-bottle system replaces a commercially available
device with a design that is more convenient and incorporates recycled

Commercial hydration systems include a plastic bladder that is easy to
puncture, difficult to clean and expensive to replace. In addition,
wearing a backpack that holds the bladder is annoying. A bite-valve
system that works with an ordinary plastic bottle sitting in the
frame-mounted cage would be preferable. The solution in a nutshell is
to combine a few purchased components with a purpose-designed tapered
Delrin stopper in order to create a home-made bladder-free hydration
system (Figure 1).

The hard problem to be solved is that bladders collapse when water is
removed but recycled plastic bottles do not. Make-up air must
therefore be added to the bottle as water is removed to prevent the
user's ears from popping. The way to do this is mount a small
check-valve next to the drinking hose. The main challenge is figuring
out how to fit both a drinking hose and check valve on a space the
size of a bottle top.

As described in the system drawings (Figures 2 and 3), a threaded hose
barb is screwed into a tapped hole next to a short piece of hypodermic
tubing on which the check-valve is mounted. The assembly is secured
by the soda bottle cap in which a hole has been made using a punch.
Beverage-grade tygon tubing is used to attach the purchased bite-valve
as well as to make a pick-up tube for the bottle. Hoses are joined
via quick-connect couplers that contain an anti-siphon valve, so that
the hose, once filled by the rider stays filled. The system does not
leak when inverted. The drinking hose is mounted to the handlebars
with cable clamps for easy access (Figure 4). The tubes may also be
attached to a larger bottle on a rack for hot-weather commuting
(Figure 5).

System details have been published on the Instructables website to
prevent others from patenting the main concepts
I machined the stopper at the hobbyist facility called TechShop in
Menlo Park, CA (Figure 6). I would love to work with anyone who has
cheap access to an injection molder to develop a more practical
fabrication method.