Pumps vs Co2 inflators?

[73Eldo]

For the last year and about 2000 miles since my return to riding I have been carrying a fairly small pump. I knew it would take a lot of pumping to do my 26x4 or 29x 2-3 inch tires and just to try it did a 26x4 one time. It wasn't horrible. Last week I had my first flat(s) out on the road. Cause seemed to be not especially well fitting or high quality tubes so something I should reasonably be able to avoid in the future so I'm not expecting to needing to be inflating a lot of tires.

Having to inflate 2 29x2.5's on the side of the road one may have been leaking while I was pumping seemed like it took 1000's of strokes. This happened 4 miles into a 40 mile ride so it plus all the pumping really took the mojo out of the whole ride. I plan to still carry a pump just as a backup or for the initial tube inflation or looking for the leaks but am thinking of also getting a co2 system. Weight and space are not a huge deal, its an E bike and I always have some sort of packs. Cost was originally a concern but I probably would have paid someone $100 that other day to shorten that pit stop.

Anyone used the co2 deals? Are there any features to look for or avoid? There seems to be a lot of options for the 'heads'? and only 2 styles of the cartridges along with different yields. Looks like one variable may be some have a valve you actuate to control the flow? Others must be a valve that activates when it hits the tire valve? Once you puncture the canister it seems like they don't have any shelf life? Are we talking minutes of shelf life or maybe a day? Like if you only used half the canister doing your repair would you still be able to get he other half out of it later in the day for a top up or if you had another flat? Just trying to figure out if I would be carrying 2 canisters or a dozen to be useful on a longer ride?

90% of my rides start at home so there I have an air compressor and a Topeak digital shuttle meter that has a fill valve on it too so that is what I use for my pre ride checks. I don't carry any sort of gauge with me but if there was a need or reason I could carry that topeak which does presta or scrhader or I have a low and high pressure presta gauge too. I think my low pressure one goes to 30 which is the max I tend to run but I could be wrong and it only goes to 15, don't use it much since I got the topeak digital. I will have to read about my topeak gauge and see if you can shoot Co2 through it? It wasn't an especially cheap unit so I would hate to damage it.

[Diggs Ut]

I carry a CO2 inflater with 2 cartridges. It is the adjustable type (didn't know there was any other kind). It is good until the end of the ride/day as that is when I replace a pierced cartridge. Not sure how long it could last. Small size, no effort, work great - a CO2 inflator seemed to be the way to go. (...although I haven't needed it since I switched to Schwalbe Marathon tires - knock-on-wood)

[AZguy]

Tried them years ago, hated them. Pumps are fine for me although since I discovered stans haven't needed one in nearly 10,000mi and although I still carry one "just in case" it has only been used to help other people - almost worth it just for that although I'm more likely to help out when she's pretty =]

The CO2 is cold, frost bite is truly an issue - it numbs before it burns so you don't know you've gotten frostbite until your hand or fingers thaw out. The cartridges aren't large enough for the really big fat tires (4-5") and if you have a well defined bead they may not be able to reseat the tire if it's come out of the bead and may need more than one to get much pressure. CO2 is one of the worst gasses to inflate tires with too. It changes pressure with heat and if there's moisture in the tube it will get absorbed into it and become acidic (carbonic acid) while your pressure goes down. I wouldn't be surprised if you lose a fair bit if you have stans in the tire since it's got a lot of water in it.

Pumps are silly reliable and push air instead of yucky CO2 into the tires. Granted it may take a little longer but if you have the right pump (narrow pumps for narrow tires, fat pumps for fat tires) it's not really a workout, just a lot of pumping. You sure as heck aren't going to get frostbite - although I suppose a blister is possible but at least you'll feel that before it happens hahaha!

Did I mention I hate CO2 inflators?

[73Eldo]

Whats an adjustable Co2 inflator? I was concerned about the cold so was looking for one that at least has the insulating sleeve if not fully enclosed. Also trying to figure out which ones lock on somehow vs just kinda push on. Seems like push on could be better chance of leakage and getting frozen.

Ya why did they pick Co2? I can see initially when the idea came up 30 years ago it was an existing standard product that was out there but today it seems like bike people are selling them so why don't they go with say nitrogen? Or can't it me compressed as much? How about hydrogen to compensate for the weight of the valve cap? Or Flubber gas so we could just fly?

I do often help people too. This was the first of 4 patch kits I have used on my own bike, the other 3 were complete strangers. Same with first aid kits, I think I am on my 3rd now and luckily not needed one myself. Back in the olden days I could and did carry basically a 26 x 1.75 and 700 x 25 tube and be able to jam that into just about any adult bike I ran into but today I think I would need a trailer to cover them all so I just offer patch kits now.

[AZguy]

CO2 is liquid (like propane) at relatively low pressures, a few hundred psi, so very dense, and non-flammable

You could always use N2O canisters I suppose but they also have all the downsides of CO2... except if you have leftover you could "relax" a bit

I agree it would be nice if the CO2 inflators would screw onto the valve stem - I don't think the ones I used work that way... after trying them back in the bad old days before stans getting flats about every other ride out here from the goat heads, I just found a pump to be a much better approach

[73Eldo]

This looks maybe interesting. Looks like its a Co2 head that says it threads onto the valve but they added a pump attachment with the same thread as the canisters.

https://www.blackburndesign.com/p/core-co2fer-bike-mini-pump/

[AZguy]

That looks skinny for fat tires

A bit more money but looks a lot better for fat and I'm a huge fan of lezyne pumps: https://ride.lezyne.com/collections/...tubeless-drive

[Fred]

One of these is another possibility; a little bigger than a small pump, but mine works well. I imagine one coud recharge it (12V) on the road with an inverter or srep-down transformer off the ebike battery,

https://www.amazon.com/Oasser-Compressor-Portable-Inflatables-P1S/dp/B07H3LP4LL/ref=sr_1_35?crid=1MTOC7NUW1OPR&dchild=1&keywords=portable+inflator+pump&qid=1626552527&sprefix=portable+inflator%2Caps%2C262&sr=8-35

[73Eldo]

Battery death from non use was the first thing that popped into my mind. Someone needs to build one that can run in the 48-52 range so we can run it direct off out packs if needed.

[Fred]

Here's one that runs at 48V. May be a bit bulky for some.

https://www.amazon.com/uxcell-Portable-Electric-Compressor-Inflator/dp/B073GYXD4S/ref=sr_1_38?dchild=1&keywords=48v+pump+bicycle&qid=1626570624&sr=8-38

[AZguy]

I think that 48V pump makes a lot more sense than a rechargeable one for nearly all electric bike applications, Much more than CO2 since size and weight are less an issue.

My reality is that I just don't need a pump for >99.9% of riding. I haven't needed to use a pump trailside in years after sealing the tires. So I'll carry one like carrying a spare tire in the car which in all reality likely get used more and I still don't bother to carry a bottle jack and real tire (I do in the 4x4 but that's different). I guess if I were riding more deep in the backcountry, particularly solo, I might go back to carrying a patch kit too I guess - or better yet go fully tubeless and just carry a plug kit.

Now if I were going to be changing tires pressures a lot, say to run deep sugar sand and then go back to pointy rock territory perhaps an electric would make more sense for my use cases

In the end I have to ask in these days where sealing a tire is tried, true and pretty darn painless, what is someone doing wrong that they need a pump more than every fifth blue moon?

YMMV

[TNC]

I hate CO2 stuff too. I use a Topeak Mountain Morph. It's like a small floor pump with a little foot that you can fold out and step on. It's much easier than having to do the isometric exercise of a hand pump. It always works, and I don't have to worry about whether I have enough CO2.

MOUNTAIN MORPH® | Topeak

[73Eldo]

Interesting, looks to be about $40.

[Diggs Ut]

CO2 is one of the worst gasses to inflate tires with too. It changes pressure with heat

OK - Lets' stick to the facts. Charles Law states all gases expand with temperature at the same rate. CO2 expands no more and no less than Oxygen, Nitrogen or any other gas. It is also less reactive and corrosive than oxygen when mixed with other elements. My inflator has a thick foam sleeve over it (freezing has never been a problem) and securely threads onto the valve stem before I turn on the variable gas valve to inflate the tire. You guys can pump away with a manual pump on a hot day (never any shade when I had a flat). Your challenge with fat tires is many pumps. My challenge was pumping 75-90 psi. Either way, I'll take the CO2 inflator. Works like a dream, is tiny even with cartridges and I don't even have to raise a sweat. It's hard to believe those that don't like them have even used them. They are better than sliced bread.

[AZguy]

OK - Lets' stick to the facts. Charles Law states all gases expand with temperature at the same rate. CO2 expands no more and no less than Oxygen, Nitrogen or any other gas. It is also less reactive and corrosive than oxygen when mixed with other elements. My inflator has a thick foam sleeve over it (freezing has never been a problem) and securely threads onto the valve stem before I turn on the variable gas valve to inflate the tire. You guys can pump away with a manual pump on a hot day (never any shade when I had a flat). Your challenge with fat tires is many pumps. My challenge was pumping 75-90 psi. Either way, I'll take the CO2 inflator. Works like a dream, is tiny even with cartridges and I don't even have to raise a sweat. It's hard to believe those that don't like them have even used them. They are better than sliced bread.

OK, let's stick with the facts =]


Boyles law and Charles law only apply to "ideal gasses" - which would stay gaseous all the way down to absolute zero at all pressures and temperatures. For real gasses those are only linear (straight line) approximations and the further a gas deviates from "ideal" the less well they apply.

Gases like oxygen or nitrogen behave much closer to an ideal gas such that those approximations are plenty close enough for normal temperatures and pressures but even those gases will deviate strongly from those approximations at extremes. Those real world gases just plain aren't linear either.

CO2 even at atmospheric pressure will condense into a solid at about -80°C vs. the ~-273°C (absolute zero) of the ideal gasses those approximations apply to so the scale is already slid by close to 200°K. Not to mention it will condense at room temperature at about 5.8MPa (~830psi absolute, ~815psi gauge) and this drops considerably at colder temperatures further offsetting the bias points in the ideal gas approximation. CO2 is quite non-linear too - it is a very curved line.

However in the real world on top of all those deviations from ideal gas is that it is very soluble in water and when it dissolves in water that lowers the pressure a *lot* and this is likely going to have an even greater effect than the ideal gas deviations. That solubility is highly dependent on temperature and pressure and very rapidly increases with pressure and decreases very rapidly with temperature, especially when under pressure. Unless you've only used a dry gas to inflate your tires, they will have plenty of moisture in them - nature of the beast. Sealants like stans are full of water too. This will also acidify the moisture and while it's not that acidic (think soda pop acidic) and likely doesn't affect the rubber much, I'm not so sure about the sealants although I'm sure plenty of folks are using CO2 with them, but if it reduces their life at all I'm not on board.

I've experienced this in the real world. I used to carry CO2 in my off-road vehicles - mostly so we could air way down in sand a then quickly get back up when heading back into the rocks. I've measured how much that pressure with CO2 fluctuates with elevation and temperature changes and it ain't pretty, especially where pressure deviations make a big difference like moto tires. After fighting that I stopped using CO2 in those applications. For the large off-road vehicles I got a high volume electric pump and for motos I took one of those <$20 noisy little 12V diaphragm pumps and took them out of the case - the little pump is really small, fist-sized, so very portable and even though they are very low volume they work pretty well for moto tires and would be great for bike tires if we had 12V handy (someday, someday!). That 48V one that they linked to is likely very small if you take it out of the case.



Now for the real world of bikes

For decades riding in the desert full of thorns and other pointy things (just about every creature in the desert is flat out mean, especially plants!) I used to accept a flat every other ride. I was using the CO2 cartridges for a year or two. When I finally graduated to fat tires (4+") they were a lot more hassle. It sometimes took more than one cartridge and when you are out of cartridges you are out of gas so you better have that pump too. And then one time I inadvertently was grabbing a cold part and got a pretty nasty frostbite since it numbed the area so quickly I didn't realize I was getting burned. So I went back to hand pumps and really came to the conclusion after going through plenty of cartridges is that the *only* advantage that the cartridges offered was that they were faster for sure. Even though the pump takes longer (and we're only talking a couple of minutes - real world) it's not a workout (I've done it in >45°C), just a lot of movement - or maybe I'm just in better shape LOL. Pumps are super reliable, will get to whatever pressure you need and does it with air vs. nasty old CO2.




But anyway to me this is almost a silly discussion. Times have changed. More real world...

I moved on to using tubeless sealant aend even riding in the AZ desert haven't had a flat in >9000mi over several years (touch wood) so just leaving a good pump (as mentioned I'm a big fan of lezyne) strapped to the bike frame seems appropriate, especially considering how seldom it sees use - almost always just to help a nice young lady with a flat.


Ride on!

[Diggs Ut]

OK, let's stick with the facts =]


Boyles law and Charles law only apply to "ideal gasses" - which would stay gaseous all the way down to absolute zero at all pressures and temperatures. For real gasses those are only linear (straight line) approximations and the further a gas deviates from "ideal" the less well they apply.

Gases like oxygen or nitrogen behave much closer to an ideal gas such that those approximations are plenty close enough for normal temperatures and pressures but even those gases will deviate strongly from those approximations at extremes. Those real world gases just plain aren't linear either.

CO2 even at atmospheric pressure will condense into a solid at about -80°C vs. the ~-273°C (absolute zero) of the ideal gasses those approximations apply to so the scale is already slid by close to 200°K. Not to mention it will condense at room temperature at about 5.8MPa (~830psi absolute, ~815psi gauge) and this drops considerably at colder temperatures further offsetting the bias points in the ideal gas approximation. CO2 is quite non-linear too - it is a very curved line.

However in the real world on top of all those deviations from ideal gas is that it is very soluble in water and when it dissolves in water that lowers the pressure a *lot* and this is likely going to have an even greater effect than the ideal gas deviations. That solubility is highly dependent on temperature and pressure and very rapidly increases with pressure and decreases very rapidly with temperature, especially when under pressure. Unless you've only used a dry gas to inflate your tires, they will have plenty of moisture in them - nature of the beast. Sealants like stans are full of water too. This will also acidify the moisture and while it's not that acidic (think soda pop acidic) and likely doesn't affect the rubber much, I'm not so sure about the sealants although I'm sure plenty of folks are using CO2 with them, but if it reduces their life at all I'm not on board.

I've experienced this in the real world. I used to carry CO2 in my off-road vehicles - mostly so we could air way down in sand a then quickly get back up when heading back into the rocks. I've measured how much that pressure with CO2 fluctuates with elevation and temperature changes and it ain't pretty, especially where pressure deviations make a big difference like moto tires. After fighting that I stopped using CO2 in those applications. For the large off-road vehicles I got a high volume electric pump and for motos I took one of those <$20 noisy little 12V diaphragm pumps and took them out of the case - the little pump is really small, fist-sized, so very portable and even though they are very low volume they work pretty well for moto tires and would be great for bike tires if we had 12V handy (someday, someday!). That 48V one that they linked to is likely very small if you take it out of the case.



Now for the real world of bikes

For decades riding in the desert full of thorns and other pointy things (just about every creature in the desert is flat out mean, especially plants!) I used to accept a flat every other ride. I was using the CO2 cartridges for a year or two. When I finally graduated to fat tires (4+") they were a lot more hassle. It sometimes took more than one cartridge and when you are out of cartridges you are out of gas so you better have that pump too. And then one time I inadvertently was grabbing a cold part and got a pretty nasty frostbite since it numbed the area so quickly I didn't realize I was getting burned. So I went back to hand pumps and really came to the conclusion after going through plenty of cartridges is that the *only* advantage that the cartridges offered was that they were faster for sure. Even though the pump takes longer (and we're only talking a couple of minutes - real world) it's not a workout (I've done it in >45°C), just a lot of movement - or maybe I'm just in better shape LOL. Pumps are super reliable, will get to whatever pressure you need and does it with air vs. nasty old CO2.




But anyway to me this is almost a silly discussion. Times have changed. More real world...

Dude - Really? No wonder others don't like to play here........

[AZguy]

I'm not sure what the problem is - initially I made a very simplistic point about CO2 and pressure changes with temperature when used in tires that was totally on topic, a simplistic reply was made that that response was somehow incorrect and so I got in the weeds since clearly my first comment was overly simplistic

Is that a bad thing? I suppose the response can be moved to it's own thread if for some reason it seems inappropriate here, but it sure seemed appropriate _and_ civil to me... and who are those "others that don't like to play here"?... there are other electric bike heavy boards with folks that don't hesitate to do far less civil responses in similar cases


Oh well... can't please everyone...

Ride on, have fun!

[Retrorockit]

AZ is an airplane guy, and needs to know this stuff. Putting the wrong type, or amount of gas in an airplane tire can have consequences.
"Let's stick to the facts" was your idea Diggs. If this produced more facts than you would like that's too bad.
"Others don't like to play here" are weasel words.No one is stopping you from going and playing with "others". I suspect there aren't very many.

[TNC]

Quote from Diggs Ut..."Dude - Really? No wonder others don't like to play here........"

I'm not getting your take on that statement. AZ didn't and hasn't in my estimation had any habit of making disrespectful posts on discussion matters. Being open and frank with supportive information isn't hateful or mean. Having a difference of opinion on something like CO2 cartridges and their application is nothing to get one's shorts in a wad over. And on another note, perhaps one should look up the word "preference". While there are clearly "facts" contained in both Diggs' and AZ's comments on CO2 and pumps, a lot of it comes down to preference for one's given situation. Diggs, you stated that CO2 carts are "better than sliced bread". Well...is that wheat or white...or rye...or pumpernickel?

[DiggyGun]

I’ve got this one, which is screw on and has an outer protection sleeve.

Got it from Amazon.
https://www.amazon.co.uk/dp/B017KU1D...17CBDKQWQCK8R0