# Flat Tire/No Hole?



## paganopj (Oct 6, 2008)

Ok....I might not be the sharpest tack in the box but how do you get a flat tire when the presta valve stem is locked closed and the tube has no hole? I spent 20mins roadside looking for a hole and finally just spent the CO2 capsule and blew it back up...10 miles later tire's still fat. Just to clarify this tube was just changed out the other day after I flatted. Could I have done something odd when I installed it? I put 31 miles on after I changed the tube, this was the 2nd ride after change.


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## Dave Hickey (Jan 27, 2002)

Have you tried sticking the tube underwater to find the hole?

My guess is what ever cause the flat the first time is still imbedded in the tire...


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## ARP (Mar 7, 2002)

*Did it pop or go flat slowly?*

Check the valve stem where it connects with the tube. Carrying a tube tightly compressed in a wedge bag under the seat can sometimes damage the valve stem to the point of failure. Jerking it about while trying to inflate with a mini pump will do the same thing.


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## paganopj (Oct 6, 2008)

I didn't hear a pop....but it seemed to deflate pretty quickly. I was about 5 miles in to a ride and thump, thump, thump, again after putting 31 miles on it yesterday w/no problems. 

This tube didn't get changed out roadside first time, I just bought it Fri, took it home and put it on. I admit I did forget to undo the screw (at the valve) when I tried to inflate it Friday (duh) but I don't see how that would screw up the valve stem. Maybe I did, who knows.

After 20+ mins of looking at this tube roadside and going up and down trying to force air out, I can say with some certainty that there is no hole and nothing lodged in the tube.


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## Mr. Versatile (Nov 24, 2005)

I'm placing my bet on either a faulty valve or a fault in the tube at the base of the valve.


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## jmlapoint (Sep 4, 2008)

*Swimming Lesson*

Pump the tube up until it bulges and put it under water with good lighting.


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## Dinosaur (Jan 29, 2004)

You've got a hole somewhere...I don't check to see where the puncture is on the tube when riding, I check to see what caused the tire to flatten, slap a new tube in and continue on my ride. When I get home, later on, I will check to see where the puncture is. Sometimes the hole is so small you have to dunk it in water to find it. Usually I repair a bunch of punctured tubes at once.


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## jmlapoint (Sep 4, 2008)

Dinosaur said:


> You've got a hole somewhere...I don't check to see where the puncture is on the tube when riding, I check to see what caused the tire to flatten, slap a new tube in and continue on my ride. When I get home, later on, I will check to see where the puncture is. Sometimes the hole is so small you have to dunk it in water to find it. Usually I repair a bunch of punctured tubes at once.


I agree.
Something caused the tube to go flat, so pumping it up and continuing to ride on it without solving/treating the problem is just futile.
Check for Tire or Rim debris or sharp edges, put in a New Tube, pump, and ride.
When home, repair the flat tube.


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## danl1 (Jul 23, 2005)

I've seen this happen with imperfections at the stem/tube joint. Something (perhaps a bit of oil on the stem during manufacture?) allows leakage at that joint, but only under certain conditions. At low pressure, it may be unnoticable. At high pressures when mounted, it can press into the rim hole to seal the problem, but certain combinations of wiggling while airing up or hitting a bump the wrong way may knock it loose. 

CO2 inflators can create or exacerbate this problem. If they're not held perfectly vertically and controlled slowly, liquid CO2 can make it into the stem. The resulting temperature change as it boils off is more than rubber can handle, and it cracks. A lesser version of this problem - not enough to ruin the tube outright, but enough to weaken the joint - could be a contributor.


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## paganopj (Oct 6, 2008)

Well I went back (after finding it had lost some air after sitting a few hours) and found two very tiny holes so perhaps I pinched it on the first go round or on the way back in...I think also the valve is shot...too as you can hear the valve leaking even after tightening the nut. Lesson learned I suppose.


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## danl1 (Jul 23, 2005)

paganopj said:


> Well I went back (after finding it had lost some air after sitting a few hours) and found two very tiny holes so perhaps I pinched it on the first go round or on the way back in...I think also the valve is shot...too as you can hear the valve leaking even after tightening the nut. Lesson learned I suppose.


The 'two tiny holes' that are characteristic of a pinch flat aren't usually an installation error. A 'pinch flat' occurs when a (usually underinflated) tire hits a hard edge out on the road, and pinches the tube between ground and edge of rim. That can easily happen with CO2, as they often don't inflate fully (especially with 12g cartridges) and what gas is there exits through the rubber relatively quickly. A tire filled with CO2 will need to be filled before the next day's riding. 

In my experience, most installation-error flats are far more dramatic.


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## paganopj (Oct 6, 2008)

danl1 said:


> The 'two tiny holes' that are characteristic of a pinch flat aren't usually an installation error. A 'pinch flat' occurs when a (usually underinflated) tire hits a hard edge out on the road, and pinches the tube between ground and edge of rim. That can easily happen with CO2, as they often don't inflate fully (especially with 12g cartridges) and what gas is there exits through the rubber relatively quickly. A tire filled with CO2 will need to be filled before the next day's riding.
> 
> In my experience, most installation-error flats are far more dramatic.


One of the reasons I'm inclined to lose the CO2 inflation system and just buy an on bike pump. As hard a time as I had getting the CO2 rig off the valve, no wonder the valve is shot. Seems easier to me to just use a hand pump and a new tube roadside. (My newbie-ness is showing now)


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## jmlapoint (Sep 4, 2008)

I use CO2, but don't like the modern 'push-on' Stem-Heads.
I still use the old Screw-On Stem-Head Cylinders.
To use it, one merely loosens the Stem Nut and Screws the Brass Cylinder onto the end pf the Stem much like the little Brass Schrader Adapters. Then you just Screw the CO2 into the end of the Cylinder until it punctures and the tube/tire inflates. When done, you just Unscrew the CO2 and the Stem-Head. No pushing, no pulling and no stem damage.
Don't know why they stopped making these in lieu of the newer push-on Heads. Guess they worked, were small & light and durable. Nobody wants something like that in today's 'throw-away world'.


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## danl1 (Jul 23, 2005)

paganopj said:


> One of the reasons I'm inclined to lose the CO2 inflation system and just buy an on bike pump. As hard a time as I had getting the CO2 rig off the valve, no wonder the valve is shot. Seems easier to me to just use a hand pump and a new tube roadside. (My newbie-ness is showing now)


No noobishness there... an evolution that most intelligent cyclists eventually make. A good minipump is lighter than head+carts, works every time, and when used properly takes only 60-90 seconds more than the best case with a CO2 system. Given the time the whole process takes, it hardly matters at all.

The only time it matters is on a group ride with a group that both has a no-drop policy and is impatient. That makes little sense, so let them resolve it by passing over one of their carts if they feel the need.

Worth noting that there are a bunch of crap minipumps, and ones meant for mtb are of no use to us.


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## jmlapoint (Sep 4, 2008)

The nice thing about a Mini Pump is if you happen to screw up, you can just start over.
Not so with CO2.
I prefer CO2, but still carry a Mini Pump for a back-up.


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## Mr. Versatile (Nov 24, 2005)

jmlapoint said:


> The nice thing about a Mini Pump is if you happen to screw up, you can just start over.
> Not so with CO2.
> I prefer CO2, but still carry a Mini Pump for a back-up.


Me too. I like the C02 because it's fast & convenient, but I have a carbon Topeak mini pump for back up.


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## brblue (Jan 28, 2003)

paganopj said:


> Well I went back (after finding it had lost some air after sitting a few hours) and found two very tiny holes so perhaps I pinched it on the first go round or on the way back in...I think also the valve is shot...too as you can hear the valve leaking even after tightening the nut. Lesson learned I suppose.


for valve leaking, you can get a glass of water, put the wheel with the valve upwards and sink the valve in the glass of water - you'll see if anything leaks:

- on almost any tube i've had, the valve was a 2 piece thread-in so valve leakage happened because the whole valve became unscrewed - nothing a pair of pliers/small fixed wrench and a piece of teflon tape won't fix. If the valve is a one-piece, and it's shot then there's time for w new tube..

- when checking a tube while on the road (no water avail to sink the whole tube in), simply patch everything that looks like a hole/dimple on the surface of the tube. My tubes often had something that looked like a hole that began leaking air only at high(er) pressure

good luck
brblue


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## mysweetride (Dec 31, 2008)

*Patches*



Dinosaur said:


> You've got a hole somewhere...I don't check to see where the puncture is on the tube when riding, I check to see what caused the tire to flatten, slap a new tube in and continue on my ride. When I get home, later on, I will check to see where the puncture is. Sometimes the hole is so small you have to dunk it in water to find it. Usually I repair a bunch of punctured tubes at once.


How well does patching hold up? I've yet to try it.


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## jmlapoint (Sep 4, 2008)

Patching a Stem problem doesn't work.
Patching a hole in a tube works fine and tube is good as new.
Use a new tube on the road - Patch tubes at home.
IMO,
John


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