Why Are Presta Valve Cores Removable? Distant Rain Clouds

No route change today. Since it is Tuesday the route goes south and east on what I call Atascocita – Walden – Spanish Cove Drive. This would be the 21st ride on this route in 2023, probably the route I ride most often. I didn’t start as early as I wanted rolling away at 9:24 AM. After the recent number of flats I decided to air my tires to 80 psi instead of 70 psi to see if that helps. Today’s bike was the Cervelo Caledonia. The front tire has a removable Presta valve core and my pump screws onto the valve stem. After airing up the tube when I unscrewed the air chuck it loosened the valve core and let the air out. I tightened the valve core up with my fingers but not enough. Finally I used pliers to lock the valve core in place and it held. That caused most of the delay. I did see 4 cyclists on W. Lake Houston Parkway as I rode south they headed north.

Riding east over Lake Houston the clouds ahead looked like they contained rain which the forecast mentioned as a possibility. When I reached FM 2100 the clouds moved away and I continued south to Spanish Cove Drive. I would’ve skipped Spanish Cove Drive if they looked threatening. The hot weather has not ended but Space City Weather wrote that it might by the end of September. Weather for today’s bike ride: Start 89 degrees, 70% humidity, dew point 77.7, partly cloudy, wind S 6 mph; Finish 92 degrees, 58% humidity, dew point 74.6, partly cloudy, wind SW 12 mph gusts 17 mph. I didn’t realize the wind increased during the ride though coming back over Lake Houston was into a headwind and my legs worked hard. Link to my AXS.SRAM.com ride report. I finished at 12:14 PM. No rain on this ride.

9-5-2023 Strava Ride Summary Atascocita-Walden-Spanish Cove Drive

Rick, my guess is that the removable valve cores originally were made with threaded exteriors so that a faulty core could be removed, without having to replace the entire tube. As tubeless later started to gain traction, that probably helped with avoiding gunked-up valve cores & such. I have yet to try tubeless – have read a lot about it, and can see the benefits, but it’s also kind-of involved, seems to be at least, and so far I appreciate the simplicity of tubes: no fuss, no muss.
I have a fairly new (900 miles thus far) Canyon Aeroad, with Conti GP5000 STRs, 25mm front, 28 rear; I’ve been running 72-75 psi in them as per the Silca tire pressure calculator, and that seems to work well for me. Also running about the same pressures on my old AL bike, too, 28s F & R. Don’t know the brand or size of tubes that Canyon installs on the Aeroad, but thus far they’ve held air pressure quite well – when I get new tires, I want to see what kind of tubes they are, and buy some of those.
I had a spate of several flats last year on prior tires on the AL bike, before I bought the Aeroad in late June, and it wasn’t until then that I realized I had removable cores, too. Discovered that you have to be really careful with torquing those into the stem, as it’s easy to bugger up the threads. When time came to replace those tires, installed new tubes (Schwalbe) with Conti Gatorskins, and no more flat issues. I do like the ride and handling of the Gatorskins, but not sure I’d buy them again: I had an awful time mounting those on my low-end aluminum wheels, they were TOUGH to get the final edges over the rim edge, and in fact the helpful guy at my LBS told me that the sidewalls on those had extra reinforcement, which explains hwy they were so tough to mount. After I finally managed to get both done, front wheel seemed a bit out-of-true, I was afraid that the sheer force required for mounting might have warped them a bit. Even took to same LBS, they said just to ride the bike, and indeed a couple of rides seemed to correct that completely.

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Why Are Presta Valve Cores Removable? Distant Rain Clouds — 2 Comments

Brian Waldrop on September 5, 2023 at 4:09 pm said:

Rick, my guess is that the removable valve cores originally were made with threaded exteriors so that a faulty core could be removed, without having to replace the entire tube. As tubeless later started to gain traction, that probably helped with avoiding gunked-up valve cores & such. I have yet to try tubeless – have read a lot about it, and can see the benefits, but it’s also kind-of involved, seems to be at least, and so far I appreciate the simplicity of tubes: no fuss, no muss.
I have a fairly new (900 miles thus far) Canyon Aeroad, with Conti GP5000 STRs, 25mm front, 28 rear; I’ve been running 72-75 psi in them as per the Silca tire pressure calculator, and that seems to work well for me. Also running about the same pressures on my old AL bike, too, 28s F & R. Don’t know the brand or size of tubes that Canyon installs on the Aeroad, but thus far they’ve held air pressure quite well – when I get new tires, I want to see what kind of tubes they are, and buy some of those.
I had a spate of several flats last year on prior tires on the AL bike, before I bought the Aeroad in late June, and it wasn’t until then that I realized I had removable cores, too. Discovered that you have to be really careful with torquing those into the stem, as it’s easy to bugger up the threads. When time came to replace those tires, installed new tubes (Schwalbe) with Conti Gatorskins, and no more flat issues. I do like the ride and handling of the Gatorskins, but not sure I’d buy them again: I had an awful time mounting those on my low-end aluminum wheels, they were TOUGH to get the final edges over the rim edge, and in fact the helpful guy at my LBS told me that the sidewalls on those had extra reinforcement, which explains hwy they were so tough to mount. After I finally managed to get both done, front wheel seemed a bit out-of-true, I was afraid that the sheer force required for mounting might have warped them a bit. Even took to same LBS, they said just to ride the bike, and indeed a couple of rides seemed to correct that completely.
Rick Ankrum on September 5, 2023 at 4:24 pm said:

Thanks for your insight. Now when I buy tubes I try to get tubes with non-removable Presta cores. I think this tube slipped through. Like you I have held off on going tubeless for the same reasons. I use Continental Gatorskin and GatorHardshell. They are very hard to get on the rims but I have found if you get the other bead down in the valley of the rim it helps a bunch. No more sore thumbs from pushing the bead onto the rim. I use 28’s front and rear. The recent spate of flats is very unusual for my Gatorskin experience. I’ve had some tires go over 7000 miles with one flat. But I used 90+ psi then. Glad your wheel trued up.

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Why Are Presta Valve Cores Removable? Distant Rain Clouds

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Why Are Presta Valve Cores Removable? Distant Rain Clouds — 2 Comments

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