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Thread: Pinch flat?

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    Senior Member BikinPotter's Avatar
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    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?
    Quote Originally Posted by EmSV650 View Post
    ...I guess I am an Athena since that's what we're calling the females, but really I'm more like a very fat Shetland pony mare.

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    Rolling roadblock
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    My understanding is that pinch flats are usually two parallel cuts in the tube.
    With every ride, I get a little stronger. I gain a little stamina. I gain a little pride. And so I await the next ride...

    http://fmriding.c5i.net/



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    Klaatu..Verata..Necktie? genejockey's Avatar
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    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!!

    Quote Originally Posted by MattInFla View Post
    My understanding is that pinch flats are usually two parallel cuts in the tube.
    Hence the term 'Snakebite' for pinch flats.
    "Don’t take life so serious—it ain’t nohow permanent."

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    Senior Member BikinPotter's Avatar
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    Quote Originally Posted by genejockey View Post
    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!!
    Bet that cleared your sinuses!

    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.

  5. #5
    SuperGimp TrojanHorse's Avatar
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    Innertubes are cheap and fail. it happens.

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    Hey Charlie Pedal Faster
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    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.

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    Senior Member Bill Kapaun's Avatar
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    Quote Originally Posted by MattInFla View Post
    My understanding is that pinch flats are usually two parallel cuts in the tube.
    That's typical, but it doesn't mean you "must" have a "pair".
    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".

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    Senior Member mrodgers's Avatar
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    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...
    Ride no faster than your Guardian Angel can fly!

  9. #9
    Senior Member Null66's Avatar
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    Quote Originally Posted by mrodgers View Post
    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...

    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!

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    SuperGimp TrojanHorse's Avatar
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    Quote Originally Posted by mrodgers View Post
    Remind me why a $1000 bike is better than my $100 Walmart job again...
    Hm, let's go for a ride and I'll show you.

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    Senior Member MRT2's Avatar
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    Quote Originally Posted by mrodgers View Post
    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...
    Some years back, I used to hang around audiophile websites. The pursuit of the ultimate in audio systems is actually a lot like biking. You can fiddle around with some old gear you bought off Craigslist or at a garage sale for $25, or spend tens of thousands of dollars. Those who spend the big bucks tend to sweat the little details, fiddling around with different (and often expensive) speaker wire, phono cartridges, room treatments, not to mention source components, amps, and speakers. All in pursuit of the Absolute in fidelity to the original recordings.

    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. #12
    Senior Member Bill Kapaun's Avatar
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    Quote Originally Posted by mrodgers View Post
    ...........Remind me why a $1000 bike is better than my $100 Walmart job again...
    You probably wouldn't understand anyway. After all, look at the post you just made.
    Ignorance is bliss.

  13. #13
    Senior Member mrodgers's Avatar
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    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.
    Ride no faster than your Guardian Angel can fly!

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    Has anyone ever tried some of these solid tires?

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    Senior Member MRT2's Avatar
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    Quote Originally Posted by mrodgers View Post
    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.
    Take an hour or two and peruse car audio enthusiast forums and I guarantee you will find people spending money to deal with problems other non audio enthusiasts don't even notice. Back in the day, I was more of a home audio guy, and except for upgrading speakers, usually just stuck with the stock car stereo my car came with.

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    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. #17
    Senior Member MRT2's Avatar
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    Quote Originally Posted by LabRat2k3 View Post
    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.
    In another post, Mr.Rodgers claimed to average 14 to 16 mph on his department store bike with rusted chain and untrued wheels, but he drives his bike 12 miles to a flat MUP to avoid several hills near his house.

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    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. #19
    Senior Member mrodgers's Avatar
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    Quote Originally Posted by LabRat2k3 View Post
    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.
    This is going way off topic, but since it was spurred with talk about me..... I don't think I ever said I am averaging 14-16 mph, I say I ride 14-16 mph. My average is about 13 mph, but that doesn't concern me at all. I'm not trying to get somewhere, I'm not trying to go a certain distance in a certain amount of time, I am trying to ride approximately an hour for fitness. The fact that I ride 14 mph for 5.5 miles (the roughly 22-23 minute time that I ride 5.5 miles confirms to me I am riding 14 mph), then when I hit the 63° air and I lollygag in the tunnel at maybe 5 mph coasting for the most part to give the rear end a rest from sitting on the saddle, and then stopping on the other side for a drink obviously screws up the average. If I'm riding from here to there or I state I want to ride X miles, then I would be concerned with average and maybe I would state average when talking about it. I'm concerned with my riding speed though and such I ride 14 mph to where I turn around and ride 16 mph on the way back with maybe a 10 minute time period that I am cruising through the tunnel.

    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.
    Ride no faster than your Guardian Angel can fly!

  20. #20
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    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. #21
    Senior Member MRT2's Avatar
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    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.
    Last edited by MRT2; 09-09-13 at 11:10 AM.

  22. #22
    Klaatu..Verata..Necktie? genejockey's Avatar
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    Quote Originally Posted by MRT2 View Post
    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.
    This.
    "Don’t take life so serious—it ain’t nohow permanent."

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