Welcome to Part II of How to Patch a Tube (Part I is here). I am sure that you are as thrilled — and surprised — as I am to discover that this topic requires multiple entries.
In part I of How to Patch a Tube, you learned everything leading up to how to patch tubes, but not how to patch the tube itself. Which makes Part I quite possibly the longest-winded intro I have ever written, in the nearly-seven-year history of a blog known for extraordinarily long-winded, self-indulgent introductions.
But I promise, in today’s post you will learn everything you need to know (and much much more!) in order to patch a tube.
Step 3: Find the Leak
It’s time to put on your detective hat, because you need to find where the hole in the tube is. Now, the best way to do that is to pump the tube full of air and then submerge it in still water, watching for bubbles.
Because of this, it is very important that you always ride your bike near a large body of water. Or carry enough water and a large enough container to submerge a bike tube in.
If necessary, you may also demand other riders in the group give you their water.
Unfortunately, water can sometimes be scarce, due to some riders inconsiderately and shortsightedly drinking it.
That’s why, as a backup, when riding you should always carry a small container — no more than a quart will be necessary — full of dishwashing liquid. Simply pump the tube up, then quickly smear some dishwashing liquid on the part of the tube you think may be the culprit. If it is in fact the part of the tube that has a hole in it, the dishwashing soap will begin to bubble.
More likely, though, you will have been wrong, so it’s a good thing you brought plenty of that dishwashing liquid. Smear some more on another part of the tube. Then wait. Breathlessly. Watch the tube with fierce concentration, looking for any sign of bubbles.
Nope, that part of the tube seems fine too.
Well, obviously you’re never going to find the hole by smearing soap over a tiny bit at a time like this, so now’s a good time to pump the tube up full of air again, then go ahead and smear soap over the whole darn thing.
You should now find bubbles appearing at some point on the tube. Or, more likely, at between six and eleven points on the tube.
Go ahead and deflate the tube now that you’ve discovered where the hole (or holes) is (or are).
Now go get about six gallons of water to rinse all that soap off the tube. So hopefully you brought both a lot of water and dish soap.
Now go ahead and re-inflate and soap the darn tube, because you’ve almost certainly lost track of where the hole (holes) is (are).
This time, mark where the holes (even if there appeared to be only one hole at the beginning of this project, there is certainly a new hole by now).
Step 4: Repair the Leak
Congratulations, you’re now past the discovery period and are ready to apply the patches. Luckily for you, patch kits have advanced tremendously in the past few years, and are now extremely simple to apply, effective at sealing punctures, and reliable at keeping them sealed.
Patch kits are actually exactly the same as they were when you had to fix a flat in order to get some kind of cub scout / brownie scout merit badge thirty years ago. In fact, patch kits are interesting primarily because they represent the single thing in the whole world that has not changed or advanced — in spite of huge advancments in both adhesive and material technologies — in the past eighty years. I mean, firewood has had more technological advancements than bike tube patch kits.
But hey, if it works, don’t fix it. Right?
So first, rough up the area around the hole, using the tiny little cheese grater that comes with the patch kit. I’m not sure why you’re supposed to do this, but you are. Be enthusiastic about your roughing, but not so enthusiastic that your rough your way clean through the tube.
Now, clean the area you’ll be applying the patch to. This shouldn’t too big of a problem, since you recently applied so much dishwashing liquid to the tube that it should be ready for the operating room.
Next, apply a small amount — you’re on your own for deciding what “small amount” means — of the patch glue to the tube. Keep some in reserve for sniffing later; you’re going to want something to help even your mood out.
Oh, sorry. As it turns out, that tube of rubber cement that came with the patch kit has been all dried out since 1968. Sorry! Well, I’m sure it wasn’t really very necessary anyway. Let’s continue as if everything’s going juuuuussst fine.
Or if, by some miracle, your patch glue isn’t all dried out in the first place, let the glue on the tube dry slightly, for just a minute. So it’s nice and tacky. The time window of rubber cement tackiness between “too wet” and “too dry” lasts approximately one-quarter second, so be ready with that patch.
Peel the backing off the patch. Hopefully, you have had the foresight to have grown long, bladelike fingernails during the past several months, or there is no way in God’s green earth that you are going to be able to peel that backing off.
Press and hold the patch in place firmly until you are sure it is set — approximately seven hours.
Congratulations, you’ve patched the tube! Now you need to get it back on the wheel.
Step 5: Put the Tube Back on the Wheel
It’s very easy to get the tube back onto the rim. Just stuff the sucker back in there. Although you’ll probably have better results if you take the trouble to at least push the valve stem through the hole in the rim.
What’s tricky is getting the tire bead back on the rim. Especially on mountain bikes. But with some patience, you can do it. Just carefully ease the bead onto the rim, working your way carefully around the circumference of the wheel.
After you’ve been around the wheel about five times, you’ll realize that as you put one part of the bead on the rim, another part is coming off. Maybe if you chase it faster, you’ll catch it.
Nope, I guess not.
So instead, use the tire lever to force the bead onto the rim, holding the part you’ve already got on the rim in place with your hand. If you do everything correctly, as you get to the end there should be just a little piece of tube poking out between the rim and the tire bead, with no easy way to get it into the tire. Push it in with a screwdriver or something. Then, with all your might, lever the final tiny bit of the bead over the lip of the rim.
You’ve done it!
Now pump up the tire and put the wheel back on the bike; you’re ready to go!
Ha ha! Just kidding! Still! Because of course the tire won’t hold air.
Step 6: Fix the Patch
You now need to take the tire off the rim again and pull out the tube. Then fish around in the tire until you find the patch, which will have peeled off the tube. Get another patch and repeat Steps 4 and 5. Again. Because they will certainly go better this time, now that you’ve had practice.
Try inflating the tire again. It won’t. Take the tube out again. That’s weird; the patch seems to have held this time. Better get out the soap and look for new problems.
Yep, there it is: the new hole from when you pinched the tube between the rim and the tire. You’re going to need a couple of patches to fix that.
Step 7: Fix the Problem
Finally, you’ve done it! You’ve patched the old holes, as well as the new holes! You’re all set to ride again! Huzzah!
You should be able to ride for roughly two minutes before your tire goes flat again. Repeat all steps, except this time be confused when you discover a brand new hole in the tube.
Oh. Waitasec. Maybe it would have been a good idea to feel along the inside of the tire, to see if there’s something sharp stuck in there.
After rubbing your fingers along in the tube for a minute or two, you should discover the sharp thorn / piece of glass / rattlesnake fang protruding through the tire. The thing that caused the flat in the first place. And by “discover,” I of course mean, “discover by the means of that sharp object puncturing and lodging itself in your thumb.
Now you just need to work that out of the tire, which should be no problem if you happened to bring a set of extra-pointy needle-nose pliers as part of your tube-repair kit. Otherwise, you’re going to get to discover exactly what the inside of a tire tastes like as you try to bite and pull the offending sharp object out using your front teeth.
Then, go through Steps 4 – 6 as many times as necessary. Which, I regret to inform you, is probably more times than you have patches
Then get a new tube out and use that instead.