Borrowed a mates airshot to put some tubeless tyres on but I don’t really want to borrow it every time I want to change a tyre or whatever. The £50 is a bit more than I’m willing to pay at the moment, is there a cheaper alternative that will give out a shot of air?
I made my own from an empty CO2 fire extinguisher. With a decent hose kit and some fittings you could do it for about £30, depends on the cost of the fire extinguisher.
CO2 extinguisher for me. Managed to get an old extinguisher for free, other parts required: a presta valve cut out of an old tube, the hose and head from an old pump, and the case of an old pen to make a barb to hold the hose in.
Unbolt the horn, cut it off, then push the hose through the washer. I was lucky that the hose I was using was pretty much a perfect fit. I cut a conical barb out of a metal pen tip and stuck it in the end of the hose to keep it secure.
The extinguisher has a safety valve on it, held on with a vented bolt. To state the obvious: make absolutely certain that the cylinder is empty before undoing this bolt.
I drilled out the bolt to fit a presta valve. The safety valve is a little foil button held in this by bolt which simply drops out, and conveniently leaves space for the base of the valve.
Job done:
I did stop to think before removing the safety valve from a gas cylinder. The valve was marked at 94 bar. By my sums, a cylinder charged to 150psi (10 bar) would need to reach 2,500 degrees C before hitting that pressure. The rubber on the base of the valve and in the valve core will be gone at about 200 C.
Tests seem to suggest that a 2l bottle will be able to hold 150psi. Probably enough to inflate tyres but maybe not repeatedly. I think I’d put some gaffer tape around for security.
I did an extinguisher too, it’s great. Mine is a big 27 litre number so on the one hand, it’ll inflate pretty much anything- it’s better for tough tyres than my compressor. But on the other, inflating it is a project. I tend to charge it up off the compressor in the garage 😆
Powder fire extinguisher: free from tip
Emptying it in to the wheelie bin: priceless
Valves: free (leftover)
Hose and track pump head: free (cheers ir_bandito)
Primer & Paint: £9.
This might seem a bit pedantic – but I have an issue with these inflators out there that look like a fire extinguisher but aren’t… 😕
I’ve been using a coke bottle wrapped in duct tape for a while.
Charging it up scares the crap out of me. I hide in my full face lid and put the bottle behind a metal chest for fear of ending up like a cheap plastic version of that bond villain with diamonds in his face.
Definitely going to keep my eyes open for an extinguisher!
2 litre pop bottle wrapped in gaffer tape, hose and some valves out of old tubes. Total cost about £3.50.
I’ve had mine up to 80psi so far and it seats plus tyres fine. The tape is the saver, if it did go bang it should protect me from flying shards………….. hopefully.
For me, I find that 75% inflate fine with a track pump and a bit of sweat and for the remaining 25%, 16g CO2 carts are cheap as chips so I just burn one of these – plenty to get two tyres seated. Got enough clutter around the garage, although I reckon there’s always room for playing with fire extinguishers…
I just use a normal 16ounce co2 inflator. The canisters are pretty cheap and I don’t change that many tyres. They have never failed to pop the tyre on.
oldtalent – Member
I just use a normal 16ounce co2 inflator. The canisters are pretty cheap and I don’t change that many tyres. They have never failed to pop the tyre on.
lustyd – Member
I just use CO2 inflators. They are a pound each and work fine for me so far
It’s been suggested that the extreme cold shock of the CO2 leaving the cannister is not good for some of the sealants and may cause them not to work as well as expected.
For the lack of hassle the airshot is fantastic, portable and even good for a hold bag on a plane.
FWIW all 6 of mine are working just fine and have been since about xmas. The CO2 isn’t colder than the conditions I rode in over winter so I’d say it’s quite safe. I did fill mine indoors and the valve was at the top away from the sealant. Given that the sealant would have been 21C at the time I doubt that quantity of C02 dropped it to any kind of worrying temperature.
If you want to test this, get a glass (by which I mean a plastic!) of water and let off a CO2 cannister into it and see how far the temp drops. Physics suggests it won’t be much; internet forum science says it’ll freeze 😯
Wide rims and/or a *lot* of soap bubbles around the rim, and a track pump.
I used to do CO2, but got the knack of using a track pump now. Wider rims seem to have a tighter grip on the tyre bead as it seats also.
As for CO2 and sealant, yes it’s been long said it may turn them into “Stanimals”. Not sure it’s temperature, just that CO2 and some sealants don’t mix. Just use the CO2 to seat first then, deflate, add sealant by removing valve core or popping a small bit of the bead. Re-inflate with track pump.
Personally, I seat the tyre bead with the tyre “dry” and once it’s banged onto the rim, I remove the valve core, add the solution and then re-inflate. In theory, at least, the cold CO2 and Stan’s fluid never come into contact…at least until I’m sat freezing on a moor in the snow!
Sat at my desk chuckling about “Stanimals” – I think I have a couple at the back of the garage somewhere 🙂
I though the CO2 issue was that it was desiccated, rather than anything to do with cold? So effectively it was drying up the sealant (to some degree at least)
I though the CO2 issue was that it was desiccated, rather than anything to do with cold? So effectively it was drying up the sealant (to some degree at least)
If this was the case, all (or virtually all) of the CO2 gets exhausted from the tyre between the initial “seating” inflation and adding the fluid so I still don’t see this being a problem.
On the trail is a different question. I am pretty sure that my fluid becomes less effective after I’ve done a trail inflation with CO2 and I’ve often found that a week or two later, I have to remove the tyre and replace the fluid.
My understanding was that it’s the CO2 in the atmosphere that sets the sealant when you get a puncture, so if you use a CO2 canister you’re causing a whole load of sealant to solidify prematurely.
bruneep – Member
How do you know you have to replace the fluid? Do you do a weekly check?
Pretty much, or just now and again shake the wheel. If I hear sloshing then it’s got plenty. If not then I’ll think about topping it up sometime soon. It might still be okay, but if you get a more sizeable hole there may not be enough sealant to plug it.
My understanding was that it’s the CO2 in the atmosphere that sets the sealant when you get a puncture, so if you use a CO2 canister you’re causing a whole load of sealant to solidify prematurely.
Where do you get the air from to blow your tyres up?