The whole CO2 inflator thing

[brucelee]

I have a topeak pocket rocket (no gauge) and was frustrated at not being able to get my tyres (28x700 Gatorskins) up to the desired pressure(117 PSI) on a ride, and since I rarely puncture and have a park track pump, decided to get a CO2 inflator (https://www.planetx.co.uk/i/q/TOBAAIRMCO2P/barbieri-airman-universal-co2-cartridges-inflater-with-pressure-gauge-115psi) and some cheap CO2 cartridges from LIDL. I got my annual puncture (brag - and as usual I was only a few hundred meters from my front door) yesterday and decided to try it out. The gauge failed instantly and upon connecting the track pump, found I had only 40PSI having used the entire canister. Is this what is to be expected from CO2 inflators generally ? Should I perceiver with them ? If not, I need a really decent pump, with a gauge. Maybe one of those seatpost ones. All thought welcome.
Cheers,
Bruce.

[NATURAL ANKLING]

Hi,
Gauge...............on hp tyres use your thumb.

My Koga Miyata came with a frame pump in 83 still on bike and still works.
My Raleigh Randonnuer came with a frame pump in 96 still on bike and still works.
Short of this I carry a Beto two way PU302, lives on the frame next to the front water bottle and goes through winters and floods, gets up to about 70 - 75 psi IIRC (will check this later), just blank the valve rubber (reversible) (schrader end) with a plastic presto cap.

At home always use the track pump.

https://www.ebay.co.uk/itm/Beto-Alloy-M ... rk:74:pf:0 7.59
Theres one other on ebay at 6.76

[Brucey]

if you have a track pump at home, and use the bike for day rides, you don't need a gauge on the pump you carry; your thumb will tell you enough to get home, surely.

Also, 117psi seems like quite a lot for a 28mm tyre; most folk would have less pressure in than that. What is your thinking here?

If you want to get tyres up to that kind of pressure at the roadside, you need a decent pump. I like Zefal HPX.

cheers

[NATURAL ANKLING]

Hi,
70 psi and 150 grams, get you home for sure.

[brucelee]

Also, 117psi seems like quite a lot for a 28mm tyre; most folk would have less pressure in than that. What is your thinking here?
cheers

Speed.... This is the max spec pressure for these tyres https://www.conti-tyres.co.uk/road-and-track/clinchers/gatorskin, I've always thought it was rather high for a 28mm tyre but works for me. Also I'm kinda heavy, so if I've got an under inflated tyre I can really feel the shimmy. Was looking for a CO2 based solution but it sounds like my expectations are unrealistic.

[Brucey]

many rims won't safely take that load (Load on rim ~= tyre width x tyre pressure).

This

https://janheine.files.wordpress.com/2010/10/bertopresschart.jpg

suggests that if you are toting over 70kg dead weight on each wheel then maybe 117psi is about right. IME unless the roads near you are billiard table smooth then you might not go any quicker on tyres that are inflated to that pressure; it may just feel 'fast' in that it isn't terribly comfy any more.

cheers

[Mick F]

Hi,
70 psi and 150 grams, get you home for sure.

Yep.
No issues from me.

[Ellieb]

It depends on the size of the cartridge. There are various charts:
https://reviews.mtbr.com/inflation-char ... -co2-sizes

[NATURAL ANKLING]

Hi,

Hi,
70 psi and 150 grams, get you home for sure.

Yep.
No issues from me.

Just in case it was misunderstood, I was referring to my beto pump and what psi I managed out of it.
IIRC Mick F carries canisters?

[Brucey]

It depends on the size of the cartridge. There are various charts:
https://reviews.mtbr.com/inflation-char ... -co2-sizes

they don't mention that the cartridge cools itself as it discharges, and in cold weather the pressures achieved in the tyre using CO2 may be measurably less than in warm weather, even if there are no leaks.

cheers

[Redvee]

I run my 25c GP4Seasons at a little over 100psi and a 16g cannister is enough to get it upto over that pressure. Currently pay less than £1 per cannister too, Lidl et al charge too much. As for covers to stop ice burn a short section of inner tube works though 25c tubes need lubricating to get on.

https://www.co2cartridges.co.uk/co2-car ... cartridges

[philvantwo]

Mick F paying to blow his tyres up!!!

[brucelee]

It depends on the size of the cartridge. There are various charts:
https://reviews.mtbr.com/inflation-char ... -co2-sizes

Yea, these are 16gram cartridges, and there was a little leakage - The tool froze onto the valve and the o-ring needed a drop of silicon grease though the canister itself didn't seem to get very cold. I'll have another crack at it and see what happens.

[philvantwo]

Don't forget when you get home, let the tyre down and re-inflate with your track pump!

[flat tyre]

The best inflator I've found for road tyres is the one by Genuine Innovations. It's lightweight and small with no flow regulator. A 16 g capsule gets a 25mm tyre up to over 90 psi in a second. You need to be careful not to hold the CO2 capsule as it inflates the tyre though, otherwise it ends up frozen to the palm of your hand (ouch! How do I know this?).