Introduction: Bike Tire Blowout! How to Fix-a-Flat

About: Design prof married to an instructables junkie.

Riding along you feel a sluggish sensation in the rear. It is a relatively flat paved trail, and it's the beginning of your ride so the legs aren't failing you, yet. In this particular instance the loss of air pressure from the rear wheel was accompanied by a click clack sound, and an audible hiss. It's official, you have a flat!

First thing first, locate the source of your flat. In this instance the shard of glass was all too prevalent. Carefully remove debris and discard safely away from the trail; so this little ugly doesn't wreck havoc on another bike tire.

Now let's get to work, and get back to the ride.

Step 1: Remove the Tire From Rim

Procedurally this is well aided with a bike tire removal tool - I picked up a Park Tool tire lever tool three pack for just a few bucks at the local bike shop. It is well worth the money, and makes tire removal much easier.

Work the wedge edge of the tool between the rim and tire, pry upward with some force, and unseat the sidewall of the tire so it overlaps the rim. With the lever still in-place, work the tool around the rim to REMOVE ONLY ONE SIDE of the tire from the rim.

Step 2: Remove the Tube

Locate your tube valve, unscrew (if necessary) locking nut on rim-side of valve before you attempt to remove tube. Press valve through rim, and gently work over the rim so you can remove the entire tube.

Step 3: Fix-a-Flat Repair Kit / What You Need!

I wear a CamelBak on all rides. I haul around all requisite tools and kits needed to fix, or limp me back to the trail head - just in case. Always have the following at your disposal:
1. Mini-Hand Pump
2. Tire Lever
3. Tire Patch Kit - go large, you never know.
4. Extra 29" tire tube (not in the Camelback this day)

Step 4: Inflate and Inspect

This seems like an unnecessary step in this particular case given the prominent and obvious gash in the tube. However, in most cases the puncture is smaller and less obvious. Inflate enough so you can audibly locate the puncture - if there is any doubt, use some good ole spit to locate site of puncture. The water/spit will bubble at the site.

Step 5: Rough It Up

Within your tire patch kit there are various rough it up devices. Sandpaper or the nifty mini-micro plane work well.
Clean and dry the area, rough up an area around the puncture site - larger than the patch. This helps the patch adhere to the tube.
Next, grab your small tube of vulcanizing fluid (rubber cement) and apply a generous amount at the site. Rub around with your finger. Let the cement dry fully before you proceed. This will only take a minute or so - it's quick!

Step 6: Apply the Patch

First, remove the aluminum/tin backing from the patch - leave the clear film on the patch.
Second, apply the patch across the puncture site. Typically aiming for dead center of the hole so as to make the best of patch coverage. Press the patch onto the tire working across it to increase adhesion.
Slowly remove the clear film from patch. *Note: this is optional, and unnecessary, the patch is not going anywhere except back in the tire so...let's get on with it.

Step 7: Put It Back Together

You will need to inflate your tube at this point for two reasons:
1. To check your handy work. Did you actually fix the flat? Is it holding pressure?
2. You need just enough tube pressure to help assist with putting it back into the tire, and tire onto the rim. Not too much mind! Otherwise, you will struggle putting the tire back on the rim.

Step 8: INSPECTION & Tube in / Tire on / Pump It Up

HOLD YOUR HORSES, Cowgirl!
Before you go shoving that beautifully patched tube back into the tire. First, a quick inspection of the interior of the tire for any residual debris, or other nasties. I have, on more than one occasion, skipped this step to find an additional thorn, or some sort of other ugly that punctures the tube AGAIN!

1. Inspect tube, clean inside if necessary and remove any other protrusions. Be careful.
2. Work tube back into the tube - between the rim. Locate your valve hole in rim, and maneuver the tube valve into place. Work the valve through hole, and screw on your valve nut to secure tube in place.

3. Most tire can be re-seated by hand. Simply start at the valve and rotate rim, and tire until you get the entire tire back on the rim. You can also use your handy tire tool lever to assist.

4. Time to pump it up! Inflate the tire to recommended specs. (60 psi, for a 29" wheel, with a hand pump - whew.)

Step 9: Hand Pump Basics

Buy a hand pump that accommodates both schrader and presta valves. The pump head easy unscrews to reveal two basic parts that when reconfigured in opposite configurations, accommodate either valve set up.
NOTE: I also purchased a presta valve adapter so if I need to use a gas station pump...I can. Not a lot of presta valve pumps out there.

Step 10: Bike Tire Fixed / Ride On!

As you inflate your tire, be sure to check that the tube does get pinched between the rim, and also check to make sure all tire beads are remaining in place. Tire gauges are good but the thumb/hand test is fairly accurate as well. If you can push down or squeeze the tire easily....keep pumping.

Put the wheel assembly back together. Make sure your chain and brakes are aligned properly.
Do a quick cross check of all drive train and braking systems before you take off.
Now get back on the trail, and ride! Bike shown: 2008 Raleigh XXiX 29er Single.