playing around with my own ghetto inflator using a coke bottle. At around 50psi I start to feel a bit weary of the bottle going “boom”. Has anyone had a bottle explode on them? If so, at what pressure was it? I’m guessing it would be more of a hiss (cracked bottle) rather than a explosion. What pressure do most people use to get the bead seated enough to use a normal pump? On the net they go up to 100psi….

Cheers

Surely you owe it to us to start recording it and find out…

On a similar sized airshot, 140psi is about right. Good luck – could be exciting.

I regularly pumped mine up to 80 psi. I always popped it in a tough bag as a “safety measure”.
It never exploded, but It did start to bulge.
As I didn’t have a regular supply of bottles (we don’t drink fizzy stuff) I decided that I may as well make a fire extinguisher version.

Si

I wrapped my bottle in gaffer tape just in case. It makes it much tougher.

There was a thread on this ages ago, iirc a coke bottle will take up to about 150psi, a flat drinks bottle, not so much…

Whoops double post

Usually put mine to about 100-110, but keep it under a big heavy old towel whilst using it. I’ve been using the same bottle for about 3years now so starting to worry about its integrity.

During some “quiet times” when working away from home some colleagues and I took yo making bottle rockets.
We had a good supply of plastic bottles usually smaller about 1 litre max. And a very large compressor for the air supply
We concluded that the genuine coke bottles take the most pressure but when they blow. And we blew a few up it is like a bomb going off.
They don’t just split the totally explode. Usually the top pops first but if you can keep the top on and the bottle blows I wouldn’t want to be within 20 feet.
Shards of small jagged plastic going through the air.
I wouldn’t do it to blow up tyres!

thanks guys. Sounds like i need to stop being a wuss and just pump it up. I like the idea of putting inside a bag though….hadn’t thought of that. The fire extinguisher method is next on the list.

NorthCountryBoy – not sure i’ll get anywhere close to air compressor pressure – a fun experiment though!

not sure i’ll get anywhere close to air compressor pressure

Most compressors only get to 6-8 bar. 88-125psi. My road track pump will do 180psi. It’s bloody had work though.

The Frankenflator has a safe working pressure of 350bar – 5000psi. 😯 I can’t get much past 140psi before my arms fall off.

Bigblackshed – what hose / head is that? Need one for mine as currently just using a bit of hose that’s prone to popping off!

Cheers,

Si

Mine makes funny hissing at around 60 psi but thats through the two valves I screwed through the cap and silicone sealed. I’m shit at that kind of stuff

I just built one using a 2L sparkling mineral water bottle. Got two Rocket Rons that I was having problems with to go up no bother at 60 psi each.

Scc999

Topeak Twinhead Joe Blow replacement hose kit.

Price matched @ Evans Cycles

+1 – though it doesn’t reinforce the base. Take mine up to 100psi.

I use still water bottles. Used to go to 100psi, now go to about 75/80 as it still does the job.

I messed around with bottles but it’s pretty bad tbh- I never felt like it inflated a tyre that I couldn’t have done with my joe blow mountain

(standard comment I make in every tubeless thread; what you want isn’t necessarily a good pump, you want a high volume pump. I had a nicer pump before but it shifted far less air. As a general rule, if it does high pressures, it’s probably not very good for tubeless)

Anyway- fire extinguisher inflater is awesome. Not as good as a full compressor, but obviously more portable, and cheaper. (you can pick up expired or discharged extinguishers easily). Just remember to mark it up clearly- you don’t want anyone trying to put a fire out with it 😆

Airshot is good too, I was surprised by how good actually, i thought the receiver was a bit small. I wouldn’t want to try and inflate my fatbike tyres with one though.s

Just found This Article on Pop bottle pressures. Interesting that in ‘normal’ use a full bottle of pop is around 50psi and can go up to 100psi if left in a hot car.
According to the article bottles seem to be able to withstand around 150psi.

Love the EVH paint job on that extinguisher!

You don’t need 100psi.

You need lots of air at a reasonable pressure.

I have a 2L coke bottle, with some unnecessary gaffer tape around it. I pump it up to about 60psi. That gives you lots of air at a reasonable pressure, and is invariably enough to get the tyre seated if I’ve done the preparation properly.

If I haven’t done the preparation properly, then no amount of air is going to fix that anyway.

I rarely took mine over 80ish but over 120 was generally held to be where trouble was likely I think.

In practice (from experience) blowing the tube you’ve shoved over valve stem threads off is likely to happen before anything bad.

My 20p Asda Cola bottle eventually after a couple of years blew the cap off, but as it was anchored by pump hose it wasn’t really an issue.

Currently with an SKS Aircon 6 track pump and not needed such bodgery the last few times.

I think as always it’s all about the rims and tyres you’re trying to make work together. I like WTB tyres and rims, and they just inflate for me like there was no drama… no crazy pumping efforts needed. 🙂

+1 what oldnpastit said. I made one that didn’t seal very well on the valves and I couldn’t get it much past 40 psi. Tried it anyway and turns out it works fine so I’ve not tried to fix it or improve it; just ‘get it going’ so that it’s hissing all over he place, release the crimp and pffft, tyre’s up.

Couple of quid for the stickers…ditch the coke bottles and build your own!

Hmmm…
An old winery trick: a handful of dry ice & a bit of water in a coke bottle = big badaboom.
So a little bit of dry ice & water + controlled release = tyre on a rim.
In theory.

Was able to get hold a pneumatic reservoir. Easy to adapt as it already has holes and threads for standard fittings plus its designed for just this purpose.

http://ep1.pinkbike.org/p6pb14112650/p5pb14112650.jpg
http://ep1.pinkbike.org/p6pb14112649/p5pb14112649.jpg

My coke bottle one is a good few years old and still works really well. Wrapped up with lots of tape so if it fails it can’t just explode. Only ever pump it up to about 50psi , as long as the tyres been prepped properly then this will inflate a 2.25 29er ok.

…I regularly pumped mine up to 80 psi.

…Usually put mine to about 100-110

…Take mine up to 100psi.

Some of you lot might live a bit longer if you calmed down a bit!

have a go at 30-40 psi, you might be pleasantly surprised…

(just to get the tyre ‘up’, then finish off with just the track pump)

I did build my own – out of a coke bottle. Used for ghetto tubeless following Stan’s original instructions before he sold kits so possibly older than anybody else’s. Saw an extinguisher in a ditch the other day and did think about rescuing it, but the current one works fine. Oh and I don’t routinely pump to 100psi now, though doing it the original ghetto style was harder to get tyres to seat (can mostly seat tyres on Stans rims with a track pump, but really struggled that way with ghetto) – though the question was about what pressure the bottle can take, so I thought the max I’ve taken it to might be a useful data point.

Kiwijohn – you’ve sort of just described a CO2 inflator (although your method would avoid the temperature/sealant problems that the inflators have).

I’ve had 2l fizzy pop bottles up to 120psi. I’m fairly sure thay’re rated up to about 150-180.

In my experience, 65psi is enough to get a tyre on though.

i just inflate up to 50psi ish. dont need more. i`ve a well used crappy pop bottle the wife recons looks like a bong. i recon a 50psi bong would give ‘interesting’ results

its good for the soul to have a bit of mild peril every now and again. a bodged pop bottle is one of these moments.

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. 50 PSI in one of those is perfect (equivalent to 75 psi in a 2 litre).

Fizzy drinks bottle wrapped in a couple of layers of gaffer tape with inner tube valves screwed into the cap.

40psi for CX tyres
50psi for mtb tyres (usually)

I had to do 80psi a couple of days ago to get some 3.0″ b+ tyres to seat fully and that seemed fine.

I’m using a garden sprayer. Easy to convert, much neater and less worrying than a pop bottle.

My 2 litre coke bottle works reasonably well at 50 psi.

But the Airwave Tubeless inflator track pump I bought is a lot neater and a bit more reliable.

Thinking of the CO2 in water idea up there.

My Higher chemistry class just estimated that for a 2 litre tyre to get up to 3.5 bar you need about 10g of dry ice.

I haven’t scrutinised their working yet but thought some of you might be interested.

This is the most STW plan ever- make inflating tyres easier, by manufacturing dry ice.

(having said that, I could go and liberate some… Actually, why don’t I do that anyway, and just spend the rest of friday fannying about with dry ice? Anyone got any molten copper?)

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.

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)

2.4 29er Racing Ralphs went up with 40psi

I wouldn’t want to try and inflate my fatbike tyres with one though.s (airshot)

i diD both my 4″ on 80mm rim fat bike tyres with a bontager flash charger, past 160 psi into “the red danger zone” though

I need to do all sorts of fannying around to get mine to mount, so it really needs the duration you only get from a compressor with a big receiver. It’s not a fatbike thing, it’s the rim/tyre combo. But once they’re up, they’re up!

My Higher chemistry class just estimated that for a 2 litre tyre to get up to 3.5 bar you need about 10g of dry ice.

I haven’t scrutinised their working yet but thought some of you might be interested.

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