"ghetto" tubeless inflator bottle pressure

Hmmmmm, I have access to industrial quantities of dry ice. Hmmmmmm………….

I thought co2 messes with the sealant so is not advised to use in a tubeless tyre

richmtb – you’re right. They used 24 l/mol for their calcs and ended up closer to 13g in the end (I’d looked over before they were finished). Was quite impressed with them as they were just using mental arithmetic and estimations after they’d finished the actual work I set them.

trout – depending on the tyre/rim combo you could seat the tyre with CO2, let most of it out, add sealant and pump back up. It’s what I did with my CX tyres and it worked fine.

The CO2/water thing is a bit of a non-starter in reality though as it’s pretty slow to evolve the gas.

I’d use a bit more than 13g.

I use a garden sprayer and it’s always done the job.

As I was going to home base, anyway, I checked out what they had – this one is similar to mine, and cheap enough for it to be an easy decision (if you’re that worried about pop bottles exploding)

http://www.homebase.co.uk/en/homebaseuk/homebase-pressure-sprayer—5l-038510

philtricklebank – Member
I use one of those 50% extra 3 litre coke bottles. Mr. Boyle states you can use 2/3 of any given pressure of a 2 litre bottle and get the same amount of air into the tyre.

Northwind
True, but not necessarily at the same speed- and it’s speed of delivery that makes or breaks tubeless (otherwise you could seat a tyre with a shock pump)

That’s true, although I doubt the driving pressure is ever the limiting feature in flow rate for these things, so I think a 3l bottle is a better bet. The flow rate into the tyre is governed by Hagen-Pouseille so things that will make the most difference is a wider bore, and shorter length of tube (between the bottle and the tyre).

For what it’s worth I tested my 3l sparkling water bottle (reinforced with duct tape) up to 150psi. I filled the bottle with water which isn’t compressible therefore doesn’t store energy like compressed air, then used a long air line and covered it all with a heavy blanket so if it did explode I wouldn’t die. As above though, it’s not necessary to use more than about 70-80 psi for inflating tyres IME. It’s also worth noting that a bottle that’s been inflated/deflated multiple times and is scratched/creased is likely to be a lot weaker than when brand new. If I was using these things regularly, I’d replace the bottle periodically.

Sod it its friday afternoon and I’m bored

A mole of gas at STP takes up 22.4 litres.
a mole of CO2 weighs 44g
so 10 grams of CO2 takes up 5.1 litres at STP
so would be 2.5 bar inside a 2 litre tyre

+ 1bar of atmospheric pressure (assuming you’re not doing this all in a vacuum) =3.5bar?

belugabob – Member
I use a garden sprayer and it’s always done the job

makes some sense, how did you adapt it?

belugabob – Member
I use a garden sprayer and it’s always done the job

makes some sense, how did you adapt it?[/quote]

Not much, really.

The metal rod section screws onto the trigger handle, so simply remove it.
On my sprayer, the resulting ‘nozzle’ fits directly over the valve (after removing the core) but you may have to attach a short length of hose, to make this easier.

Pump it up, attach to the valve, and press the trigger – bingo!!!

(It even comes with a built in pump)

I have several blue fire extinguishers. CO2 or powder>
Anyway I would like detailed instructions of how to get the valve in it. Ie the bit that lets you inflate.
Anyone

It probably varies from model to model tbh. I used a big water one which had a gauge that threaded into the head- unscrewed gauge, drilled hole, fitted tubeless valve

http://singletrackworld.com/forum/topic/ghetto-tubeless-inflator-mk-vii

Here you go , been using one for a couple of years with no no problems .

I’ve had about 80psi in a 2ltr bottle without problems. In previous workshop experiments 2ltr Evian bottles would take around 160psi before exploding with enough force to blow a hole in a cheap internal door

https://www.youtube.com/watch?v=CB4ND8sFdFU

mattsccm – Member
I have several blue fire extinguishers. CO2 or powder>
Anyway I would like detailed instructions of how to get the valve in it. Ie the bit that lets you inflate.
Anyone

Easiest way is to fill it from the outlet. I have a tee on mine with a shut off valve. Hold the handle or tape it, fill wth air.

belugabob – Member
belugabob – Member
I use a garden sprayer and it’s always done the job

“……makes some sense, how did you adapt it?”

Not much, really.

The metal rod section screws onto the trigger handle, so simply remove it.
On my sprayer, the resulting ‘nozzle’ fits directly over the valve

well that was jolly pleasing just took one of mine apart and yes it fitted nice and tight straight onto the valve 😮 cheers – yet to use it in anger as am still stuck at stage one getting the tyres on to the rims for a tubed pre-inflate reckon it’ll be a couple of weeks at least before I report back 😕