Pinch flat?
#1
Pinch flat?
I ride a mtb with street tires which I keep well inflated. Not overinflated, but not low pressure. Sitting watching something on tv & heard a hissing noise. At first thought it might be on the tv. No...turned off the sound to discover one of my tires going flat. Took the wheel off, checked it over very carefully. Couldn't find a thing wrong...no glass, nails, wires, sharp stones, anything. Pulled the tire off & the tube out & pumped a little air in, then stuck it into the sink filled with water to find the leak. A tiny, tiny slit, not on a seam. Carefully checked the rim, nothing sharp. So...pinch flat? Or did the tube simply fail?
#3
Klaatu..Verata..Necktie?




Joined: May 2007
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Bikes: Litespeed Ultimate, Ultegra; Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace; Cannondale R500 RX100; Schwinn Circuit, Sante; Lotus Supreme, Dura Ace
You're lucky it was a hissing. I once had a rim with a worn-out rim strip. I replaced the tube, pumped the tire up, and 10 minutes later, as I sat nearby BANG!!
Hence the term 'Snakebite' for pinch flats.
Hence the term 'Snakebite' for pinch flats.
__________________
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
#4
I put in a new tube & haven't had any further problems, so I don't know what happened. It is what it is, I guess.
#6
Old and in the way.
Joined: Feb 2008
Posts: 355
Likes: 47
From: Eugene OR
Bikes: Jamis Renegade and Kona Jake
I used to get a lot of pinch flats on my rd bike. It's been better since I started over inflating... I also went up a tire size in the rear but I started with 23s so that probably won't help you.
#7
Really Old Senior Member


Joined: Feb 2007
Posts: 14,668
Likes: 1,905
From: Mid Willamette Valley, Orygun
Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds. 2019 Giant Explore E+3
Possibly the bike was leaning at a slight angle and one side got "munched" just a bit harder.
I apparently did that a few days ago when turning into my driveway and hitting the "lip".
#8
All these posts I read on here about flats and broken spokes really worry me about eventually buying a "good" bike. My bike is 8 years old and I paid $99.99 at Walmart for it. Changed the original tubes out just a month ago and though the wheels may not be exactly round or straight (brake shoes rub in 2 spots when I spin them), no spokes has ever broken. Heck, I can't complain about changing out the tubes after 8 years, can I? It was even ridden many many times in the yard with almost completely flat tires because I would be at work and my daughter would just dig it out of the garage and ride it around.
Both tubes I replaced because they had holes right at the valve.
Remind me why a $1000 bike is better than my $100 Walmart job again...
Both tubes I replaced because they had holes right at the valve.
Remind me why a $1000 bike is better than my $100 Walmart job again...
#9
Senior Member
Joined: Jun 2013
Posts: 2,114
Likes: 3
From: Garner, NC 27529
Bikes: Built up DT, 2007 Fuji tourer (donor bike, RIP), 1995 1220 Trek
All these posts I read on here about flats and broken spokes really worry me about eventually buying a "good" bike. My bike is 8 years old and I paid $99.99 at Walmart for it. Changed the original tubes out just a month ago and though the wheels may not be exactly round or straight (brake shoes rub in 2 spots when I spin them), no spokes has ever broken. Heck, I can't complain about changing out the tubes after 8 years, can I? It was even ridden many many times in the yard with almost completely flat tires because I would be at work and my daughter would just dig it out of the garage and ride it around.
Both tubes I replaced because they had holes right at the valve.
Remind me why a $1000 bike is better than my $100 Walmart job again...
Both tubes I replaced because they had holes right at the valve.
Remind me why a $1000 bike is better than my $100 Walmart job again...

Uhm, I think you'll be even happier if you true your wheels. A few minutes with a spoke wrench.
But I do have to ask, just how many miles are on your bike these last 8 years?
But back in the 80's I would have loved the department store bikes. Aluminum rims!
Steel wheels with chrome braking surfaces brake horribly in the rain!
#11
Senior Member

Joined: Jun 2007
Posts: 6,321
Likes: 221
From: Wisconsin
Bikes: 2012 Salsa Casseroll, 2009 Kona Blast
All these posts I read on here about flats and broken spokes really worry me about eventually buying a "good" bike. My bike is 8 years old and I paid $99.99 at Walmart for it. Changed the original tubes out just a month ago and though the wheels may not be exactly round or straight (brake shoes rub in 2 spots when I spin them), no spokes has ever broken. Heck, I can't complain about changing out the tubes after 8 years, can I? It was even ridden many many times in the yard with almost completely flat tires because I would be at work and my daughter would just dig it out of the garage and ride it around.
Both tubes I replaced because they had holes right at the valve.
Remind me why a $1000 bike is better than my $100 Walmart job again...
Both tubes I replaced because they had holes right at the valve.
Remind me why a $1000 bike is better than my $100 Walmart job again...

The non audiophile plays his or her music through whatever he or she has laying around. Ipod dock, boom box, garage sale special, and thinks it sounds pretty good.
You have mentioned more than once that your wheels wobble badly. You keep saying it like it is a badge of honor to ride a bike seriously in need of adjustment. Why not just get your wheels trued?
Last edited by MRT2; 09-08-13 at 08:45 PM.
#12
Really Old Senior Member


Joined: Feb 2007
Posts: 14,668
Likes: 1,905
From: Mid Willamette Valley, Orygun
Bikes: 87 RockHopper,2008 Specialized Globe. Both upgraded to 9 speeds. 2019 Giant Explore E+3
#13
Hey. it was just an attempt at just being funny, hence the smiley
Sorry if it didn't come out that way in text form. If I had a couple of hundred for what I needed to put into this bike, I'd be picking something up on CL or something for a couple of hundred.
Audio? Yes, I too was a big audiophile back in the day, only with my car. No, I didn't go around beating out that rap crap, I built for topaudio quality in the car. Heck, its all 20 years old now and I still have half of it in my current car.
Sorry if it didn't come out that way in text form. If I had a couple of hundred for what I needed to put into this bike, I'd be picking something up on CL or something for a couple of hundred.Audio? Yes, I too was a big audiophile back in the day, only with my car. No, I didn't go around beating out that rap crap, I built for topaudio quality in the car. Heck, its all 20 years old now and I still have half of it in my current car.
#14
Junior Member
Joined: Jun 2007
Posts: 5
Likes: 0
Has anyone ever tried some of these solid tires?
#15
Senior Member

Joined: Jun 2007
Posts: 6,321
Likes: 221
From: Wisconsin
Bikes: 2012 Salsa Casseroll, 2009 Kona Blast
Hey. it was just an attempt at just being funny, hence the smiley
Sorry if it didn't come out that way in text form. If I had a couple of hundred for what I needed to put into this bike, I'd be picking something up on CL or something for a couple of hundred.
Audio? Yes, I too was a big audiophile back in the day, only with my car. No, I didn't go around beating out that rap crap, I built for topaudio quality in the car. Heck, its all 20 years old now and I still have half of it in my current car.
Sorry if it didn't come out that way in text form. If I had a couple of hundred for what I needed to put into this bike, I'd be picking something up on CL or something for a couple of hundred.Audio? Yes, I too was a big audiophile back in the day, only with my car. No, I didn't go around beating out that rap crap, I built for topaudio quality in the car. Heck, its all 20 years old now and I still have half of it in my current car.
#16
Senior Member
Joined: Jul 2013
Posts: 201
Likes: 0
From: West Virginia
Bikes: 2012 Cinelli Xperience
I know you said you were joking but just in case someone else is wondering the same thing I'll share my personal experience. I started with a box store MTB on July first of this year and then upgraded to my "real" bike in mid-August. The advantages I have seen are: My average speed has increased by 4.5 to 5 MPH, not only is going fast more fun, it burns more calories. Because I am traveling at a higher rate of speed I also cover more ground in the hour I set aside for riding each morning, burning even more calories, I've gone from 7 to 8 miles to 14 to 15 miles a day. My more expensive bike shifts when I want it to which lets me make it up hills that I was unable to get up before, the lighter weight helps here too. My cheap bike would shift whenever it felt like it if at all, most times I would try to shift when I came to a hill and nothing would happen until I was halfway up and really straining to keep pedaling, then it would jump to the next gear,my feet would fly off the pedals and I would loose all my momentum. Because I can get up more hills now it has opened up other areas for me to ride, which adds to the enjoyment of riding. So did I need a new bike? Probably not, but I am getting more out of my time and enjoying it more so it was worth it to me.
#17
Senior Member

Joined: Jun 2007
Posts: 6,321
Likes: 221
From: Wisconsin
Bikes: 2012 Salsa Casseroll, 2009 Kona Blast
I know you said you were joking but just in case someone else is wondering the same thing I'll share my personal experience. I started with a box store MTB on July first of this year and then upgraded to my "real" bike in mid-August. The advantages I have seen are: My average speed has increased by 4.5 to 5 MPH, not only is going fast more fun, it burns more calories. Because I am traveling at a higher rate of speed I also cover more ground in the hour I set aside for riding each morning, burning even more calories, I've gone from 7 to 8 miles to 14 to 15 miles a day. My more expensive bike shifts when I want it to which lets me make it up hills that I was unable to get up before, the lighter weight helps here too. My cheap bike would shift whenever it felt like it if at all, most times I would try to shift when I came to a hill and nothing would happen until I was halfway up and really straining to keep pedaling, then it would jump to the next gear,my feet would fly off the pedals and I would loose all my momentum. Because I can get up more hills now it has opened up other areas for me to ride, which adds to the enjoyment of riding. So did I need a new bike? Probably not, but I am getting more out of my time and enjoying it more so it was worth it to me.
#18
Senior Member
Joined: Jul 2013
Posts: 201
Likes: 0
From: West Virginia
Bikes: 2012 Cinelli Xperience
That brings up another good point. Average speed can be very deceptive depending on how it is measured. My average speed on my MTB was 12 to 13 MPH but I only averaged about 8 miles a day on my morning ride, now my average is closer to 17 MPH but I am doing 15 miles in the same time. How is this? My average speed was calculated on my moving time not my overall time, and I take fewer brakes now also. Previously on a 1 hour ride I would have a moving time around 40 to 45 minutes, now I'm moving for 54 minutes out of that hour. So I guess If I rode like the hare from the Tortoise and the Hare I could have a higher average speed on my MTB but cover less ground over a given time period.
#19
That brings up another good point. Average speed can be very deceptive depending on how it is measured. My average speed on my MTB was 12 to 13 MPH but I only averaged about 8 miles a day on my morning ride, now my average is closer to 17 MPH but I am doing 15 miles in the same time. How is this? My average speed was calculated on my moving time not my overall time, and I take fewer brakes now also. Previously on a 1 hour ride I would have a moving time around 40 to 45 minutes, now I'm moving for 54 minutes out of that hour. So I guess If I rode like the hare from the Tortoise and the Hare I could have a higher average speed on my MTB but cover less ground over a given time period.
So sure, average speed is very deceptive, especially if your means of measuring it takes into account stopping or moving. My computer stops if I stop. I have tried MyTracks on the phone which gives me a moving and an overall average and Runtastic which only gives overall average. None of them gives me what I'm concerned with and that is riding at a good rate for 90% of my actual riding since none can differentiate my riding down the path or wheeling the bike around in the parking lot and cruising through the tunnel.
#20
Senior Member
Joined: Jul 2013
Posts: 201
Likes: 0
From: West Virginia
Bikes: 2012 Cinelli Xperience
I never said anything about how you ride, and frankly I couldn't care less what you do on your bike. You asked a question, I gave an honest answer based on my personal experience, I thought that was what this forum was for.
#21
Senior Member

Joined: Jun 2007
Posts: 6,321
Likes: 221
From: Wisconsin
Bikes: 2012 Salsa Casseroll, 2009 Kona Blast
To answer Mr Rodgers' question, when everything is right on a bike, and everything fits, the bike becomes an extension of the rider. That is a lot more likely to be the case on a properly adjusted $1000 bike than it is on an old beat up Wal Mart special. When the wheels are wobbly, tires not holding air, and the gears not shifting smoothly, etc, etc., a lot of the rider's effort is wasted fighting the bike, or your own discomfort in the case of a bad fit. You can do it, but it isn't much fun.
We all had the experience of riding some piece of junk as a kid and somehow enjoying the experience anyway. Part of that is just being a kid. But I also seldom rode more than a few miles as a kid before I had to dismount my bike. It wasn't until I was in my 30s that I had the epiphany that when riding a bike where everything actually works and is comfortable, I could ride 20, 30, even 40 miles on one ride. Never rode more than 5 or 6 miles when I was in high school, even though I was much fitter at 15 or 16 than I am now.
We all had the experience of riding some piece of junk as a kid and somehow enjoying the experience anyway. Part of that is just being a kid. But I also seldom rode more than a few miles as a kid before I had to dismount my bike. It wasn't until I was in my 30s that I had the epiphany that when riding a bike where everything actually works and is comfortable, I could ride 20, 30, even 40 miles on one ride. Never rode more than 5 or 6 miles when I was in high school, even though I was much fitter at 15 or 16 than I am now.
Last edited by MRT2; 09-09-13 at 11:10 AM.
#22
Klaatu..Verata..Necktie?




Joined: May 2007
Posts: 23,809
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From: SF Bay Area
Bikes: Litespeed Ultimate, Ultegra; Canyon Endurace, 105; Battaglin MAX, Chorus; Bianchi 928 Veloce; Ritchey Road Logic, Dura Ace; Cannondale R500 RX100; Schwinn Circuit, Sante; Lotus Supreme, Dura Ace
This.
__________________
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
"Don't take life so serious-it ain't nohow permanent."
"Everybody's gotta be somewhere." - Eccles
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