I’m sure i’m not the first person to have come up with this, but I was so surprised it actually worked I thought I’d share....
What you need
2L Pop bottle – I used a Morrisons 9p mineral water bottle
Two old presta innertubes – I used two old punctured ones
A 5.5mm drill bit
Some plastic tubing – 5-6mm internal diameter?
Gaffa tape if you’re not feeling brave
Total cost – 9p
How you do it
1 – Cut the valves out of the inner tubes – you only need a small amount round the base
2 – Cut one of the valves about halfway down to remove the internal valve bits
3 – Drill two 5.5mm holes in your bottle lid – not too close to the edge or it won’t close
4 – Shove both valves through holes
5 – Use the presta lock rings to get a decent seal (use pliers if you have weak lady hands)
6 – Put tubing over the cut off valve
7 (optional) – Wrap gaffa tape round the bottle to strengthen it. If you’re super paranoid stick it in the cut off jeans leg. That said in my younger days we used to inflate them to 80psi and then shoot nails in them from a home made air gun (bang!)
How you use it
1 (optional depending on how stubborn the tyre is) – Remove valve core
2 – Attach other end of tubing to valve
3 – Put a good kink in the tube by folding over
4 – Attach pump to other valve
5 – Inflate to 40psi or so
6 – Remove kink (quickly)
7 – Tyre inflates very quickly!
8 – (optional) If you’ve removed the valve core do the inflation a couple of times, then put the core back in and inflate a final time
9 – Use a pump on the wheel valve to pump up to desired pressure
Seems to work a treat – had to remove the valve core on one of my new high rollers but not the other one.