Sunday, May 5, 2013

Patching Bike Tires, Method #1: The Easy Way Out

We noted a while back that one of the skills we want to develop this year is the skill of patching bicycle tires.  In particular, the road shoulders and bike lanes seemed to be cluttered with an abnormally high concentration of pokey things this last year, resulting in more flat tires than we had in the previous three or four years combined.  We were in the neighborhood of a dozen or more flats, which if replaced with a new ($5.00) inner tube every time, can start to add up.  (That's more than a tank of gas costs!  Unacceptable!)  Also, even though there's lots of uses for inner tube rubber around the homestead, eventually the tubes (or at least part of them) will end up in a landfill.  That's definitely something we want to avoid.  Fortunately, patching an inner tube can be ridiculously easy, and pretty cheap, too.  This morning, we had a patching party in the kitchen to repair the collection of holey tubes we had accumulated before getting smart.  We note that although our focus is bikes, the technique is applicable to most equipment with similar tires that can go flat, including wheelchairs and baby strollers.  It's valuable for all stages of life!

The first step (for the most recent casualty, anyway) is to get the tube off the rim.  That requires two tools with which to apply leverage and bring the tire bead outside the rim.  The one on the left is a plastic tire lever designed for this purpose and is recommended by bike experts because it doesn't scratch the rim or damage the tube.  The one on the right is a screwdriver and is not recommended by bike experts for the opposite reasons.  But we've had good luck by being very careful.  The advantage is that the screwdriver can give a lot more leverage than the tire lever.
Once the tube is off the rim, the next step is to figure out where the leak is (unless you already know).  We pump the tube up a little bit and 'listen around the tube' to see if we can hear air hissing out anywhere.
If we can't (i.e., it's a fairly slow leak), we take the tube to a bucket of water and look for bubbles.  This happens a lot if it's a puncture leak, like we somehow managed to ride over a tiny pin at exactly the right angle.
Once we know where the leak is (which in this case turns out to be an old patch that didn't hold because we're new at this), we can let most of the air out of the tube.  Make sure the tube and your hands are clean and dry.  It might also help to hold the tube flat against a table top, if one is available.  Cast iron frying pans work well as paper weights (rubber weights?)  Also pictured is our patch kit--it has six patches for $3.00.  In other words, we get a 'new' tire for $0.50, which is a little more tolerable than $5.00.
In addition to the six patches, it comes with a free 1" x 1" piece of ~220 grit sandpaper.  Bonus!  The idea here is to rough up the tire in the area of the hole to help the patch stick.  Make sure to smooth down the ridges in the tire, get rid of any superglue you might have added to the old patch because you touched the sticky side with greasy hands and the edges wouldn't stay stuck, etc.  The area where the patch is going should be flat and no longer shiny.  Also, when you've gotten to that point, make sure to clean off any rubber schnibbles from the sanding.
The rubber is now ready for its patch!  Peel the new patch off the backing, being careful not to touch the sticky side with bike grime-covered fingers, and apply the patch to the tire.  Press it down hard, like with the back of a fingernail or something, and make sure it's all even and stuff.  Man, whoever fixed that tire might not have buffed up a large enough area for this patch to hold reliably, but he should definitely be a hand model.  Mint condition, baby.  (It's almost never that clean.)
There she be!  Looks like solid B+ level work.
Some say to let the adhesive set for a while before testing it.  That may not matter for the ready-made adhesive patches as much as for other kinds of patch kits that come with rubber cement and separate patches, but since we don't need all six patched tires right away, we figured it couldn't hurt.  Thank goodness we also didn't need the frying pans, or we would have had to invent a hexacycle.
Now we've just got to get the fixed tube back in the tire and on the rim.  It's a good idea to check both the tire and the rim to make sure whatever cased the flat in the first place is not still there.  Once convinced that all is clear, pump up the tube slightly (just enough to make it round), and work it into the tire, and eventually onto the rim, starting first by putting the valve stem in place.  Yes, that is duct tape augmenting the original rim tape, which has started to lose its stickiness and doesn't cover some of the rusty spots on the inside of the rim.
Work around the rim, popping the bead of the tire back into place, being very careful not to pinch the tube in between the edge of the rim and the tire.  The job will get progressively harder as you near completion.  Some say to avoid leaving the part by the valve stem for last, but we like to end at least near the valve stem because the tube is sort of anchored to the middle of the rim there and seems least likely to interfere with popping the last section of tire back onto the rim.  It should be possible to pop the tire back on with just your thumbs, but it will take considerable effort.  Fingertip pushups will help (over time), which is an additional translatable nugget from learning kung fu (in addition to manual almond chopping).
Time to flip it over and pump it up to test!  If it holds, you can ride off into the sunset on your newly repaired bike (depending on which way you need to go).
For further reading (but fewer pictures) from someone much more knowledgeable than us, see Sheldon Brown's article on the matter.  Actually, we've found Sheldon's articles to be a good starting point for almost any bike repair.

This method of patching bike tires is probably the most convenient available.  It's also very inexpensive, but it's not quite homemade-enough for us.  We'll continue working on this skill and report back when we have a more homestead-friendly version!  In the meantime, if you have any suggestions on how to improve our technique, either to improve our results with this method, or a more DIY version, tell us about it in the comments section below!

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