There have been requests for text versions of the
fix-a-flat video published below, so here you go! Feel free to print
out. I'm cribbing this down to key items to print on a 3 x 5 and will
have them laminated in the store. I'll post when that is ready.
I’ve lost count of how many flats I’ve
fixed only to have the bit of thorn or glass that got left in the tire
puncture the new tube. Be sure to diagnose what caused the flat! Start
by taking the offending wheel out of the bike (I'll post those details
next), and then:
Dig your tire levers from your tool kit (remember your tool kit?)
Using the tire lever, or levers if necessary, remove one side only
of the tire from the rim. Remember that if the tire is an especially
tight fit you can hook the first tire lever to a spoke to hold that
section of the tire while the next lever is put into play.
The valve stem of the inner tube is
somewhat more fragile than the rest of the tube, so start this removal a
quarter of the way around the wheel away from the valve and continue
working away so that the tire near the valve is the last and easiest to
Pull the inner tube out of the tire, but leave the valve inserted through the rim.
Pump up the removed tube until it is 2-3 times normal size—big enough to hear the leak.
Tube analysis 101: Is it
a single hole? If so, you should be able to tell if it is on the ‘top
side’ or rim side of the tube. A top side single puncture indicates the
need to search the inside of the tire for the shard of debris that is
probably still there. Leaving the tire and tube partly on the wheel
helps narrow this search.
A puncture on the rim side indicates that
the rim cover or “rim strip” has failed. This strip keeps the spokes or
the rim’s spoke holes from cutting the tube.
In the case of a rim strip failure, the only correct fix is to
replace the strip. A Velox or similar cloth strip is worth it. An
emergency use of a power bar wrapper or the like can get you home.
A pair of holes—usually on the side of
the tube—indicates that you’ve hit something hard enough to pinch the
tire against the rim and have torn a puncture through the fold in the
All tires loose air over time. There is
so little volume in a bicycle tire that this loss is measurable in days.
Road bicycle tires should be checked once a week, as they will loose as
much as ten percent of their pressure per week. Mountain tires should
be checked every other week. Unchecked, this air loss makes the pinch
flat more likely.
Replacing a new tube: put a little air into the new tube, just
enough to give it shape. Start by inserting the valve into the rim and
tucking this portion of the tube into the tire—which should still have
one side on the rim. Tuck the rest of the tube up into the tire and then
‘roll’ the tire and tube over the center of the rim.
The slightly inflated tube will want to
poke out over the rim's edge—it is this ‘belly over the belt’ that will
get caught when finishing the tire installation.
Once the tube is centered over the rim,
start at the valve and begin working the second side of the tire back up
and over the rim. Work in both directions away from the valve.
Somewhere before you finish, it will get
difficult to carry on by hand and you will be tempted to take up your
tire lever and pry. Do not succumb to temptation!
In this end zone, make sure that there isn’t some tube still stuck out
over the rim's edge. Now let as much air back out of the tube as you
Push the valve stem all the way up into
the tire to make certain that the base of the valve has not been trapped
under the edges of the tire. Easily pull the stem back down. The final
trick is to lightly brace the wheel on the ground with the valve up.
Starting at the valve, pinch the edges of the tire to the center line of
the rim. Working both hands away from the valve, continue to pinch the
tire into the rim center and stretch the tire away from the valve toward
the floor. This center of the rim is slightly deeper than the edges.
By getting the sides of the tire into this center line and then all the
way around, the far end that remains unfinished should now have enough
slack to roll over the rim's edge by hand. Thumb strength helps, too.