On the way home from church this morning in my T, my son heard a hissing sound coming from the back tire and sure enough, it was pretty flat! After taking the tire off I refilled the tube and there was a pretty good sized split. No metal found, just this split and what looked like drag marks. No other holes in the tube. Then I looked on the inside of the tire for some metal object and found these two strange cuts/gouges where the split is in the tube. The weird thing is, the cuts/gouges don't go all the way through the tire to the outside - only on the inside. It sure looks like something was on the inside between the tire and tube but I checked both the inside of the tire and the ground where I took the tire off and no metal was to be found. Before I put a new tube back in, is it safe to reuse this tire with the gouges on the inside?
That H shaped cut looks like what happens when you run over something sharp in the road. All the other marks look like they came after the tire was deflated.
That's why I always carry spares and a tire pump.
Is it safe to reuse that tire with the cuts on the inside, or do I need to purchase a new tire?
Bill: If you reuse the tire I would at least glue a patch over the bad spot on the inside. get a patch at least twice as large as the bad spot. (bigger patch is better patch) They used to put "boots" in tires all the time. I would have no problems using it with a patch, but you must make your own decision as to using it, or not.... I agree with Royce, you probably ran over something.??
That is what they used to call a "stone bruise". It usually happens on an older tire, maybe there is still tread, but the tire is 10 or more years old and gets kind of brittle, then when you go over a pothole or a stone in the road, the inside casing splits causing your flat. A boot can be used and will be OK for a while, but you might notice a vibration because it will throw the tire out of balance.
Thanks, guys, for the help. I sure was baffled because there was no metal culprit to blame and nothing to indicate what caused the puncture in the tube. I think I'll just bite the bullet and get a new tire; this is the same tire I put a patch on a few weeks ago so this time I'm not taking any more chances - I've already got a new tube so why no just put a new tire on as well? BTW, what would you all recommend using to re-inflate a tire repair on the road? Tire pump? I've seen others use a small electric pump but I don't know how they get the power from their T.
Some guys say they inflate tires to 65 psi with hand or foot pumps. Fortunately, I haven't had to try it. I guess I need to restore one of my old pumps and give it a go.
I spent some time last year trying to find a larger version of the handy CO2 inflators that bicyclists use for their tires. Most bicycle systems use 16 gram CO2 cartridges.
There are 45 gram cartridges available (I believe that paint ball guns use them).
There are some off-the-shelf CO2 systems for motorcycles, but they are pretty expensive, here is a link to one supplier:
For now, I carry a fully inflated spare tire on a demountable rim, along with a patch kit and double-barrel hand pump (which I hope I'll never have to use).
Just to satisfy my curiosity, I did a rough calculation to estimate how many 45 gram CO2 cartridges it would take to fill a 30 x 3.5 inch clincher tire to 60 psi.
I know that one 16 gram cartridge will fill one of my 700 x 28c bicycle tires to 90 psi (I measured it).
Calculating the volumes, I find that the 30 x 3.5 inch tire's volume is roughly 13 times that of the bicycle tire. However, it only has to be pumped up to 60/90 = 2/3 the pressure. The 45 gram cartridge is 45/16 = 2.8 times the weight of the 16 gram cartridge, so let's roughly assume it holds 2.8 times the CO2.
13 times 2, divided by 3, divided by 2.8 = 3.1.
So, it would take a little over three 45 gram CO2 cartridges to fill a 30 x 3.5 inch clincher tire to 60 psi. Let's call three cartridges close enough.
Each 45 gram CO2 cartridge has a 1.2 inch diameter and a length of 5.4 inches, so three of them would probably pack better than a hand pump. The head unit that screws to the top of the cartridge about the size of a Model T headlight bulb. The head unit is re-usable, just unscrew it from the used cartridge and screw it onto a fresh one.
Of course, each cartridge can only be used once, so if you use them, you have to buy three more to replace them. The cartridge gets very cold when it is discharged, so you need a rag or glove to hold the cartridge so that it doesn't freeze your hand. A hand or foot pump is always ready for action, no replenishment required (just a little rest for the operator).
I may bite the bullet and purchase a head unit and some cartridges just to give it a try. If I do, I'll report back to this forum after my first use (which I hope won't be anytime soon).
But did you calculate how much gas would be unused in the following cartridges after the first cartridge has achieved equilibrium? (i sometimes overthink those things)
I think using multiple cartridges would be more efficient as the earlier ones would be left with a lower pressure, but the volume between 30 lbs and 90 lbs in a co2 cartridge would be very small.
I have a small electric pump that I have thought of throwing in, as I use a small 12 volt battery, I could wire it to that. It has got to be easier than a hand pump, but if I had one, I probably would not bother with the electric. I can not help but think of the WWI ambulance drivers changing and re-inflating by hand when they had a flat in a battle zone.
I would not trust a tire with a rip in the cord. Even if the forum consensus was that this is a
safe practice, I wouldn't be able to enjoy the car because the known defect in the tire would
be preying on my mind. Besides, gremlins love to yank on the frayed edges of this kind of damage
and make matters worse.
Kep is right, each cartridge will have some gas left in it once the pressure in the tire and cartridge equalize. The third one will have the most, since it ends up equalizing a something (hopefully) close to 60 psi.
I went ahead and ordered a head unit and four 45 gram CO2 cartridges from T-bay last night, I'll post a picture of them next to my double-barrel pump when they arrive to give folks an idea of the relative size.