Just a heads up for anyone out there who owns or uses a portable screw-on type bike pump, like ProBikeKit's pump. These pumps typically have a head that screws onto the presta valve tip, so there is no leaking of air when you pump, and often come with a flexible tube for better positioning.
I learned the hard way today that if you don't carefully pre-tighten your valve cores BEFORE you ride, these pumps will grab onto your valve core and remove it entirely from you tire (with a huge loss of all your pumped air!) as you try unscrewing it. It will unscrew the valve core instead of the valve itself, so you're left stranded with a tube with no valve. You'd think you could just pull the valve out of the pump and just screw it right back into the tube, but in my case, the pump had screws onto the core tightly enough that it was impossible to remove with my hands. (It's not super tight, it's just that you get no purchase on twisting that tiny core with your fingers. At home with wimpy pliers, it's a cakewalk to remove.)
Luckily for me I was overprepared for flats, and had extra tubes as well as my backup CO2 kit, which as of today is officially becoming my main, and likely only flat kit since it works so well. Had to redo the entire tube installation again roadside, but this time the CO2 made the inflation an absolute cakewalk. (I HIGHLY recommend the Portland Shiny Object Inflator. It is friggin' amazing. Clearly marked "open/close" on a dial, and you can dial in the precise CO2 fill amount you want, from trace amounts to check initial mounting, to full blast once you're sure it's on right. Get it, thank me later!)
I was using Conti Race Tubes for 700-20 thru 700-25 tires with 80mm long valvestems, and I've never messed with the removable core before, so now I know - you are supposed to extra tighten the core before use if you want to use these screw-on pumps ,but I'm not even going to bother and just go CO2 so this isn't even an issue. I know a lot of you folks out there use these very same tires, so be aware before you do what I did and get that tube core trapped in the pump on roadside.
I learned the hard way today that if you don't carefully pre-tighten your valve cores BEFORE you ride, these pumps will grab onto your valve core and remove it entirely from you tire (with a huge loss of all your pumped air!) as you try unscrewing it. It will unscrew the valve core instead of the valve itself, so you're left stranded with a tube with no valve. You'd think you could just pull the valve out of the pump and just screw it right back into the tube, but in my case, the pump had screws onto the core tightly enough that it was impossible to remove with my hands. (It's not super tight, it's just that you get no purchase on twisting that tiny core with your fingers. At home with wimpy pliers, it's a cakewalk to remove.)
Luckily for me I was overprepared for flats, and had extra tubes as well as my backup CO2 kit, which as of today is officially becoming my main, and likely only flat kit since it works so well. Had to redo the entire tube installation again roadside, but this time the CO2 made the inflation an absolute cakewalk. (I HIGHLY recommend the Portland Shiny Object Inflator. It is friggin' amazing. Clearly marked "open/close" on a dial, and you can dial in the precise CO2 fill amount you want, from trace amounts to check initial mounting, to full blast once you're sure it's on right. Get it, thank me later!)
I was using Conti Race Tubes for 700-20 thru 700-25 tires with 80mm long valvestems, and I've never messed with the removable core before, so now I know - you are supposed to extra tighten the core before use if you want to use these screw-on pumps ,but I'm not even going to bother and just go CO2 so this isn't even an issue. I know a lot of you folks out there use these very same tires, so be aware before you do what I did and get that tube core trapped in the pump on roadside.