I have a montague urban 700c bike, it came with kenda tires and tubes. Never a flat in two years. But the tires were worn and starting to dry rot, so I thought I’d be proactive and replace them…
Got new tires and tubes both 700×35. I put in two new continental tubes, pumped them up to 60, and within minutes both suddenly pssssssshhh and were flat. A single tear maybe 3-4mm across.
I put the old kenda tubes back in. Pump up to 60, this time a few hours later, pop and one was flat. Same tear in the same location, rim-ride.
I patch the tube, and flip it around so fresh unpatched tube is over that spot, this time I was able to ride but the next day it was flat and punctured, exactly the same
Has the hard plastic rim strips inside, no cracks or holes in the tape and don’t feel anything sharp.
Maybe something’s stuck in the rim band, I go to the LBS, got two new tubes and some rubber rim protectors, I took out the plastic ones. All is well for a few days I ride a few dozen miles. Today I went to go for a ride aaaand rear tire completely flat. Great…
I took out the tube, 4mm tear at the same location. I patch it, I cut up one of the old tubes and add it as a secondary rim band, now there’s like 2-3mm of rubber on top of the nipples. I flip the tube again so it’s fresh unpatched, I pump it up to 60, within a minute, psssshhhhh. Same spot
I’ve changed tires on my other mountain bikes… never had a problem, I’m really lost here. Nothing embedded in the brand new tires, nothing. Very careful to not pinch the tube between the tire and the rim when installing the tire. Never use a tire lever to install the tire just my thumbs.
I’m keeping the bike in the trunk of my car, is it getting too hot in the sun and over inflating? I’ve never had a flat while actually riding, but it has gone flat within minutes of inflating too so I don’t know. Does the image of the puncture (half inch to the left of the valve) tell you anything? I’m at my wits end. Thank you for any input
by SN1572
12 Comments
what’s that little thing beside the spoke nipple? Is there some sharp material there?
https://preview.redd.it/mnripsetfbah1.png?width=202&format=png&auto=webp&s=4f8765edc4fc4431d884234f2b19964eef2e4767
Most likely that rimstrip isn’t doing it’s job properly. Or your tube isn’t rated for that tyre and expanding too much but it’s weird to always fail at that same spot so unlikely.
Damn, that’s frustrating. Are you using a tire lever to get the last little bit of tire on the rim? And do you always end at the same spot?
Also, do you put a little air in the tube before installing it in the wheel? Making sure it’s not pinched between the tire and rim before inflating to full pressure?
FWIW, I don’t think the rubber rim strip is the cause. However I would recommend a cloth strip in the long run.
Volex rim tape is my go to
Assuming you are installing it correctly, it is most likely that your tire is too wide for your rim. Go down to 28 or 32.
Use cotton/fiber rim tape instead of a butyl rim strip. Butyl rim strips are trash and are a byproduct of the tube industry.
Velox Cotton Rim Tape
Newbaum’s Rim Tape
Schwalbe Cotton Rim Tape
Take rubber rim strip out & use two wraps of Gorilla Tape
Experienced the same thing. And it lasted 2 years. And it all began when I replaced 1.95″ wide tires with 2.20″ wide tires. I tried Velox. And Velox + inner tube strip. This is my travel/hotel bike. Every few weeks I pull it out of storage and it may have acquired a spontaneous flat. Or I bring it into the hotel and in the middle of the night it hisses like a cobra. Wakes me up. Other events led me back to 1.95″ tires. Otherwise I might still be dancing with it. Here’s my theory. When the tube stretches to fill the spoke channel, it gets thinner, weaker. Then when it wraps around a spoke head, it gets even more thinner, weaker. Thinner-weaker-thinner-weaker-thinner-weaker- HISSSSSSSSSSSS. And the evidence for this are the permanent dimples impressed into the tube. Permanent weak spots, waiting to go. The green you see is Green Slime.
https://preview.redd.it/28m9h4nwpbah1.jpeg?width=405&format=pjpg&auto=webp&s=76975c7024b0e855c3f573a09172a902b95042a8
Honestly? Take the plastic backing off the rim tape if that’s an option. I was having the same issue. Couldn’t figure out what was making all these slits/causing all these flats. Finally removed the hard plastic backing and haven’t had a flat in the six months since.
Rubber rim strips are terrible. Get a roll of proper Velox rim tape and you will never have this problem again.
It’s not the rim strip.
I suspect the tube ruptured from either a tire with thick sidewalls and bead not letting the tube seat all the way against the rim between the bead and or the valve stem is not properly seated against the rim. Any gap will cause a bubble and rupture like what you have.
Run a rag over the inside of your rim. Anywhere it snags file it down. Sometimes nipples have burrs.
Cloth rim strip like velox is just better than the cheap rubber type and if it saves you from puncturing one tube it pays for itself.