For years I rode 650 wheels and a 12 Gram Co2 cartridge worked great and I bought them by the box in Kmart, $10 for 15 of them
Now I am riding a 700 bike and I guess I need 16 gram cartridges, but all the discount stores sell is the 12 gram ones. Bike shops sell them for $8 for 2, but I don’t really want to spend that much money on them if I don’t have to.
Does anyone know a cheaper source for them?
Ebay in bulk - about $1 per.
Thanks! Never even thought to look there.
12g should be enough for a 700 tire. Not quite the air-pressure you might normally ride, but plenty to finish the ride. I buy them in bulk at Walmart.
12 gram works fine.
You are having way too many flats if you need to buy them in bulk to save a meaningful amount of money.
3 bikers in the house 5 bikes and lots of crappy country roads. Don’t go through all that many but don’t want to spend a fortune either. I think the last time I bought 12 gram carts (15 to a box) was in 2001 and I still have 5 left.
This year for what ever reason I have used 3 16gr ones and lost 2 tires already.
I buy mine and our clubs at this site…
http://www.gas-depot.com/co2-12g-threaded-and-16g
I think they have the best prices out there.
Hope this helps
12 grams should be fine. The difference in volume between a 650 and 700 is ~ 15%. So the final pressure would be that much lower depending on how much CO2 is lost in the process of filling. You want to dump the CO2 out of your tires as soon as you get home anyway and replace with air. But if you want a bit more pressure go with the 16 grams.
Why should you dump the CO2 and refill your tire with air? I have never done that before and just curious what ill effects it may cause?
Co2 molecules are small ennough to be permeable through the rubber of the tube. They go flat within about 12 hours aftewr filling with co2. That is why you want to get it aqll out and replace it with ambient air ASAP.
AHHHH Thank you, It can be hard to stomach the idea of releasing several dollars of CO2 when I were to get home but if it escapes easily anyway it might make it easier for me to refill with air.
PS that also helps explain why I always think I have another flat after I fill up with CO2 because my tires seem to drop pressure quite rapidly after sitting in the garage for one night.
CO2 is more permeable in rubber so it “leaks” out faster through the tube walls. Probably not a big deal and you could get away without doing so as the CO2 will be gradually replaced with air as you pump up the tires per your normal practice. It’s worse of course with latex which is why it’s recommended to carry a spare butyl tube if you rely on CO2 to inflate tires during a long race. I carry new butyl tubes for training and use them in case of flat with CO2. I’ll then remove the new tube when I get home and replace with a patched tube and test that overnight so the CO2 gets dumped as part of that process. Probably overkill but you may have noticed that I seem to obsessive/compulsive. (
Co2 molecules are small ennough to be permeable through the rubber of the tube.
It has much more to do with solubility than molecular size…