So as Flammable Dan asked me to make a thread about making a ghetto inflator so here it is:
Just to start, there are heaps and heaps of threads on other MTB forums about this as well as how-to videos on youtube. This was the one I mainly referred to when making mine:
https://www.youtube.com/watch?v=EtmatxJG_zg
And as a forewarning such a device holds air under pressure, thus it is potentially dangerous. Exercise caution when using one and wear appropriate safety gear (especially eye protection).
pressure testing bottles:
https://www.youtube.com/watch?v=SDTvjJZlnR8
https://www.youtube.com/watch?v=Dg7ohbT9O2o
https://www.youtube.com/watch?v=D78K3sW-1fA
What you need:
1 x 2-litre soda bottle (I actually used 1.5-litre bottle but would recommend a bigger bottle)
2 x presta valves cut from old inner tubes. One needs to have a removable core
1 x length of PVC tube with a 5.5mm internal diameter
gaffer tape
teflon / plumbers tape
50/50 mix of detergent and water and a rag
tools:
drill
6mm drill bit
locking pliers
length of coathanger wire or dowel rod (to push the valve through to the bottom of the bottle)
safety glasses
blanket
If you need guidance watch the first video link above. The only difference between the instructions on the video and mine is that I put the intake valve in the base so that it was easier to install the cap without the valves fouling on the top of the bottle and also so that I didn’t need to handle the bottle when pressurised. I also fitted a longer length of PVC tube from the one pictured so the bottle can sit on the ground (I wrapped this in a blanket so if it did fail sharp plastic wouldn’t fly into me).
Thoughts:
It worked well enough, seating tyres well at 100psi (I took it to 110psi). As I say a higher volume bottle would work better. The valves start to leak air when under lots of pressure without teflon tape. I tried using a bleed clasp but it didn’t stop air after about 60psi, so I recommend using locking pliers to clamp the hose. Also the PVC tube would blow off the wheel valve when releasing the pressure sometimes.
Also for the next one I make will use auto tubeless schrader valves, shut-off valve and an air blower (or tyre inflator clasp) as per this video:
https://www.youtube.com/watch?v=r3D5FAPwqj8