Friday 15 October 2010

Tubeless tyre inflation device

I made this tubeless inflator back in 2010, when I started experimenting with tubeless tyre setups on my mountain bike.

It may not seem obvious to people why I needed, or bothered, to make something like this.

Now we're in 2022, tubeless tyres are in widespread use across all cycling disciplines, not just for off-road riding.  Consequently, there is a wide variety of devices now available to inflate tubeless tyres, such as the Airshot inflator or the Bontrager Flash Point floor pump for example. However, back in 2010, there were none of these devices available.

One or two of my mountain biking friends were also experimenting with tubeless set-ups, but it was only the friends that had compressors at home.  Although tubeless tyres can sometimes be inflated with a regular track pump alone (especially with today's tubeless specific tyres and rims), back in 2010, a track pump alone wasn't usually enough.  A device is needed to get air into the tyre quicker than it can escape, to get some pressure into the tyre, to get the tyre beads 'seated' on the shoulders of the rim.  For that, a high volume of pressurised air, delivered continuously, is needed. 

I didn't have a compressor at home, and I didn't want to spent about £100 to buy one.  Also, I didn't have the space in my garage to put one anyway.  I therefore needed to get inventive.

What you see in the photo is the low-cost tyre inflator that I made.  It cost about £20 in materials, and hold 6 litres of air at pressures up to 50 psi.

Parts list:

  • 3 x 2L sparking water bottles, ~20p each.
  • 1 x spare tubeless presta value.
  • 4 x flexible tap tails from the low cost hardware store Toolstation, about £1.50 each.
  • 1 x water/Gas lever valve from Toolstation, about £5.
  • 3 x plumbing compression tees from Toolstation, about £2 each.
  • A few small spare short sections of 15 mm copper pipe.
  • 3 x O-rings and nuts to connect the bottle tops to the tap tail threads.
  • A bit of rubber tube that I had pare at home, which had the same inner diameter as the presta valve outside diameter.
I was really pleased how well this works.  The 6 litre volume takes some time to pump up with the track pump, but the benefit of all that air is that when the tyre inflates, the pressure in the bottle drops from about 40 psi to only 25 psi.  This means there is enough pressure in the tyre to pull the rubber tube off and get the valve core back into the valve stem before the tyre deflates an unseats. 

12 years on, I am still using this inflator, whenever a track pump alone won't do the trick.


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