Author Topic: Bike flats/inner tube question  (Read 12952 times)

anitalala

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Bike flats/inner tube question
« on: September 02, 2012, 08:29:14 PM »
Hi There,  it seems every time I use my bike I get a flat tire and the inner tube needs to be replaced. I wonder if you have any recommendation on preventing flats and/or brands of inner tubes, places to buy inner tubes. Not sure if it helps but I have a pretty inexpensive hybrid Marin bike.
Thank you!

Jamesqf

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Re: Bike flats/inner tube question
« Reply #1 on: September 02, 2012, 09:42:17 PM »
First, what is the cause of the flat?  Where are the tubes being punctured?

If it's thorns or something going through the tread, go to a bike shop and look for thorn-resistant tubes.  There are also puncture resistant tire liners that go between tire & tube, and even tires made to be puncture resistant.

If the punctures are on the inner side of the tube, you could have a spoke that's a bit long and rubbing on the tube.

PaulM12345

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Re: Bike flats/inner tube question
« Reply #2 on: September 02, 2012, 09:58:50 PM »
Do you know how to patch tires? You don't need to replace a tube just because of a flat - just buy a patch kit, some tire irons, and a pump. I've used patched up tubes that have lasted years. There are a few parts of the tube, like right at the valve, that can't be patched, but otherwise it works great and saves money. There are how-to videos on the web, or ask at a bike shop.

That said, as James noted, if you keep getting flats in the same part of the tube, you may have a problem with your wheel or tire. Your number of flats is suspiciously high, so I'd look into that. I once got a staple in my tire and punctured my tube multiple times before figuring out the problem...

Russ

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Re: Bike flats/inner tube question
« Reply #3 on: September 02, 2012, 10:04:01 PM »
There are a few different reasons you could be getting recurring flats. The most common is that your tires don't have enough air in them. Then when you start to ride the bike, the tire fully compresses and your inner tube gets pinched between the road and the metal wheel. This is called a pinch flat. To stop this from happening, just make sure you keep the pressure in your tires up to the spec printed on the tire sidewall. Bike tires are just like party balloons - they lose air naturally, whether you ride on them or not. I lose a little over 10 psi a week.
The second most common cause of recurring flats is when you don't remove the cause of a puncture. If you get a thorn or small piece of glass in your tire and get a flat, when you change the inner tube you need to make sure you get that thorn or whatever out of your tire. You can do this by running a rag (not your hand, unless you like cutting open your fingers on sharp things) around the inside of the tire while the tube is out. Make sure you go in both directions. This should snag on anything sharp poking through, and then you can finish the job with a pair of tweezers.
The final thing, which most people don't know to look for, is a damaged rim strip. Do you see where the spokes go into the rim of your wheel? There are holes that go all the way from where the spoke enters the inside of the rim, up to where the inner tube sits on the outside of the rim. These holes are sharp, so they need to be covered up on the inner tube side, or else the tube can get cut.That's what the rim strip does - covers the holes to protect the tube. If you can see any part of these holes when your inner tube is removed, that's a problem. If your rim strip is broken altogether, head over to the bike shop and get a new one, or if it's just shifted over a little bit you can probably move it back into position and everything will be fine.
As far as brands of inner tubes, honestly they're probably all made in the same factory somewhere in Taiwan. The only thing I actively avoid are tubes advertised as "flat-protecting", whether they're that nasty green slime stuff or just extra thick rubber. In my experience, none of that stuff really adds any protection. The slime leaks and gets all over, and anything that gets through the hard rubber of your tire will make it through a soft inner tube just fine, no matter how thick it is. There's also a few different brands of foam inner "tubes", which are some fancy closed-cell foam things you use in place of a traditional tube. I don't have any experience with these, but I have heard that you can damage the foam by hitting potholes or curbs. Not something you want to worry about with a $20 tube.
I buy all my bike things from my friendly neighborhood bike shop, on principle of supporting folks who support the sport. I don't remember the last time a big-box store did anything for cycling, but I do appreciate every time the local shop gives out free bike route maps at our weekly farmers' market.

gooki

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Re: Bike flats/inner tube question
« Reply #4 on: September 03, 2012, 01:22:46 AM »
Cheap tubes with really good trees works for me. I used to have weekly tire punctures (lots, of glass on the roads near me) then I invested in a pair of Maxxis Refuse tires and they were brilliant.

And as above, keep them well inflated.

deciduous

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Re: Bike flats/inner tube question
« Reply #5 on: September 03, 2012, 08:49:11 AM »
Most of these posts have focused on punctures, which I guess can cause lots of flats, but there are a couple other things which seem to have gotten me in the past:

  1. Using cheap inner tubes: I'm not saying you need to get them gold-plated or anything, but there are plenty of companies out there looking to make a tube that retails for $4-5 and is very weak around the valve or has bad components in it. I recently had a run of flats on tubes like that (gotten from the huge pile at performance bike) but seem to be riding fine now on some nicer $6-7 tubes. this seems like a ripoff to me, but that extra dollar or two is not yet worth my time finding something better/cheaper.

  2. Also, make sure you're buying the right tube to match your wheel and tire

  3. Flats that arise not from road hazards, but from mishandling the tube while putting the tire onto the wheel. some wheels and tires just take a ton of force and cursing to get them on there, and if they get pinched in the act, or folded over, they're probably going to blow before long. I've heard that talcum powder (or flour) can help the tube settle neatly into the right place. I've used it sometimes, but not consistently, and haven't really noticed a difference.


For what it's worth, I seem to get flats in bunches also. I went six years of constant riding without one, during which time my wheels got battered out of true. I bought new wheels and tires, but waited for my next flat to actually put them on. Once I did, I must've gone through 4-6 tubes in about as many weeks. They were almost entirely caused not by glass, but striking potholes. I think the cheap valves were blown out completely by the sudden spike in pressure.

If you really care, you can study the inner tube to find out the cause of the flat by partially inflating it and putting it under water to find the hole. Different problems result in holes that have different shapes and locations. For my sake, I just put another tube in and get on with life.

Good luck.

Bakari

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Re: Bike flats/inner tube question
« Reply #6 on: September 03, 2012, 11:13:26 AM »
I think the most likely reason for a flat every single ride is what Russ mentioned second: leaving the offending thorn, metal shard, or glass in the tire when replacing the tube.  I use my fingers, but do it lightly so I don't cut my finger.  My finger tips can feel lightly embedded things that the rag method can miss.

Some tires have a layer of kevlar (the same stuff they make bullet proof vests out of) running along the tread, or some similar extremely strong material.  They are generally advertised as "flat resistant".
You can also buy tire liners which go between the tire and the tube to provide an extra layer of protection.
In terms of puncture strength, the kevlar tire is strongest, followed by liners, followed by the resistant tubes (which are made of the same regular rubber, but thicker) that James mentioned.

You can patch a tube (much much cheaper, and less waste) unless the problem is at the valve stem, or the hole is bigger than the patch. 
Use the kind with a tube of glue (not the quick patches) for better reliability.  To find the hole, inflate the tube (out of the tire) and then put it up to your ear and turn it slowly until you hear it hiss.  If you have trouble finding the exact spot, I find holding the tube next to my lips can help, as they can feel a lighter flow of air than fingertips can.
 
Deflate the tube completely.  Rough up the puncture area with the included sandpaper.  Put on a thin layer of glue, and then let it dry completely before applying the patch.  Take off the backing, don't touch the back of the patch, press it on evenly and firmly with no wrinkles in the tube or patch.  Any wrinkles and it will leak.  Then put it back and treat it like a new tube.

Like Russ said, keep your tire pressure up.
Like deciduous said, don't pinch the tube putting it back in the tire: never use tire irons / tire levers (or any other tool) to put the tire back on.  Use your hands.  It can be very challenging to get the last bit on, depending on your tire-wheel combination.  But if you use the irons, you are very likely to pinch the tube. 

Good luck.

Sparky

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Re: Bike flats/inner tube question
« Reply #7 on: September 04, 2012, 07:24:20 PM »
Beating a dead horse here. Great tires, proper pressure and decent inner tubes is the key to no flat tires. Haven't had one in about 12 months and I ride just about daily including living on a nearly 100 pound bike.

But seriously good tires and you'll be riding on purpose through glass just to mock that you tires are stronger than glass :)

Jamesqf

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Re: Bike flats/inner tube question
« Reply #8 on: September 04, 2012, 11:12:25 PM »
Glass is no big deal.  Goatheads, now, are a different story :-(

JR

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Re: Bike flats/inner tube question
« Reply #9 on: September 05, 2012, 10:39:19 AM »
I have about ~2000 miles on a pair of Specialized All Condition Armadillo tires (700c x 28) with only 1 flat.  These tires are normally $80 a pair but I picked them up for $40 and couldn't be more pleased with them.  I don't have anything to compare them to though as this is my first road bike so I can't say if a cheaper set of tires would be just as good.  After I bought them from my LBS the owner said his wife complete the TransAmerica (4200 miles) ride on a set of them and didn't have one flat the entire ride.  I must reiterate what others have said and stress the importance of having the tires pumped up to avoid snake bites.  I keep my tires inflated to the maximum recommended pressure so that may have helped with the flats.

anitalala

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Re: Bike flats/inner tube question
« Reply #10 on: September 06, 2012, 11:26:59 AM »
Thank you all! I think not properly inflated tires might be my fault. Not sure if it's the AZ heat but they do loose pressure pretty quick. My husband has been fixing my tires so not exactly sure what has caused flats so far.