I began having this problem frequently, about 5 years ago. Nothing else about my skills or habits or rims changed from the previous four decades, so I've concluded that there is likely a manufacturing issue. Thinner/less/more brittle rubber at the base of the stem or something. There have always been the occasional "slices" due to tube rotating around the rim, or due to too-sharp edge at the valve stem hole on an aluminum rim, but this is different, and happened like you describe, one tube after another. I could be wrong, but I don't think it's possible to fix them.
Knowing that doesn't help solve your issue though. Here's what I started doing, and it's pretty much solved the issue for me: When you install a new tube, keep the knurled nut on the stem, snug it lightly, and install the tube with the nut INSIDE of the rim. Keep the nut from the old tube, and intall on the outside of the rim, the normal way, and snug firmly. This will ensure that only the metal stem will ever contact the sharp or abbrasive part of the hole in the rim, which is now sandwiched between two nuts. On Thursday, August 3, 2023 at 3:03:27 PM UTC-6 Jim Whorton wrote: > I had the same thing John P describes, tire rotating in rim, tugging the > tube along, causing the valve to tilt then tear at the base. I also had it > happen twice in a day until I decided I was running the tires at too low a > pressure. Increasing PSI solved the problem. > > Jim in Rochester NY > > On Thursday, August 3, 2023 at 4:13:13 PM UTC-4 John P. in SF wrote: > >> Hi. >> >> If what is happening to you is what happened to me, your tire is rotating >> on the rim. >> >> This sometimes happened when I was using an undersized tube like Patrick >> M. mentioned, but it happened a lot to me when using modern tires on older >> rims, and less when using a tubeless compatible rim. Flats generally >> occurred when riding somewhere that involved heavy braking, and occurred on >> around three different bikes I have or have had. Like the one time I got a >> front flat at this spot >> <https://www.google.com/maps/@37.8275685,-122.5030476,3a,75y,255.79h,85.47t/data=!3m6!1e1!3m4!1sWDi65VsGmuS7PLyVeiu63g!2e0!7i16384!8i8192?entry=ttu>. >> >> I sometimes speculate that the rim heating up somehow aids with making the >> tire rotate, which then tears the stem, but that is just a guess. >> >> Moving to a tubeless setup was the only cure I found. >> >> On Thursday, August 3, 2023 at 9:54:21 AM UTC-7 J J wrote: >> >>> Hi, I was inspired by Matthew's "Patch or Replace Tire" thread, but >>> didn't want to usurp it with my question/issue, so I'm starting a new one. >>> >>> My tire went flat during a recent ride on my Hunq. Upon inspection I saw >>> that there was a tear near where the valve stem attaches to the inner tube. >>> No biggie. I replaced the tube with a spare, got back to riding, but within >>> 15 minutes, another flat. Same tear in the same location. I replaced the >>> tube with yet another spare. This was starting to feel weird. The same >>> thing happened within a few more miles, another tube gone. >>> >>> I had no more spare tubes, but a buddy gave me one that is specced for >>> narrower tires. I managed to get back home without incident. >>> >>> The attached pic shows where the tear occurred in each instance. >>> >>> But three flats on a single ride! I replaced the tubes the way I always >>> do. Nothing dramatic about it. I used a pump to inflate two, and a C02 >>> cartridge to inflate another. I snugged the valve nut like I always do, not >>> too tight, not too loose. I handled the valve stem carefully, no jerking or >>> bending it. The air pressure was about medium, not too high, not too low. >>> >>> I used three different types of tubes, one a Schwalbe, another was a >>> no-name, and the other was a Teravail. I inspected the 50mm Schwalbe >>> Marathon tire carefully and found nothing of concern, no glass, screws, >>> metal, shards, etc. The Lesnik-built wheel itself had run fine for many, >>> many miles with no issues, no flats, nothing, and is in excellent >>> condition. I had been riding on smooth pavement when the flats occurred, >>> and there was nothing remarkable on the road. >>> >>> But suddenly, on that day, all inner tube hell broke loose. I'm stumped. >>> I don't know what to do differently so I've been thinking about the saying >>> (misattributed to Einstein): "Insanity is doing the same thing over and >>> over again and expecting different results." >>> >>> I'd be grateful for any ideas you might have or experiences you can >>> share. >>> >>> Thanks!! >>> >>> Jim >>> >>> >>> [image: IMG_8384.jpg] >>> >> -- You received this message because you are subscribed to the Google Groups "RBW Owners Bunch" group. To unsubscribe from this group and stop receiving emails from it, send an email to rbw-owners-bunch+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/rbw-owners-bunch/40340757-150b-48f9-a676-e1ff12261c19n%40googlegroups.com.
