Converting standard rims and tires to tubeless"Going tubeless" has a good side, and a bad side. Before following the instructions on this page, you should read our feature article on Tubeless Biking.
Commercial rim liner for tubeless conversion.
If you're adventuresome, you can make your own rim liner by cutting a kid's-size bicycle inner
tube (a tube designed for a 20 or 24-inch wheel) into a strip. Or, you
can put strapping tape
over the rim holes, and use a standard UST valve.
Rim liners are available from
Stan's
No-Tubes
These let you convert a standard rim to go tubeless. The rim liner weighs about 50 grams (1/4
the weight of a tube). Be sure you're getting the correct width rim strip.
Hint: The strip should be just wide enough to lean against the 90-degree corner where the tire's
bead will sit (see photos below), while the center is fully pushed down
against the tape that
covers your spokes. (An inner-tube strip will be thinner in depth than
the commercial rim liners,
and may not provide an adequate seal. It depends on your rim. If you decide
to cut your own
rim-strip, good luck.)
Tubeless tire valves.
If you're using a standard UST rim with sealant in your tire, it's handy to have a valve with
a removable core. Sealant can plug the valve, but the "glop" is easily
cleaned if the core
can be taken out of the stem.The valve on the left is a standard UST tubeless
valve. On the right is valve with a removable
core. The sides of the cap threads (the silver part just under the valve
knob) are flattened
so a wrench can be used to unscrew the core. Commercial rim-liners come
with a removable valve
core, while your "home made" rim strip's valve will eventually plug with
coagulated sealant.
Adjusting the hole to fit a tubeless valve.
You may need to enlarge your valve-stem hole to make room for the valve-stem to seat. If the
rim liner won't sit smoothly down into the valley in the center of the
rim because the valve
stem sticks up, enlarge the hole slightly with a rose-head countersink,
or with a drill bit.
Be sure you don't make the opening too large!
Hint: Schraeder (automotive type) valves have a removable core, and fit on a compressor without
an adapter. If the hole in your rim allows, consider a rim liner with
the "big valve."
Applying rim tape.
A broad plastic liner (factory-installed on the wheel) will interfere with the seating of the
rim liner. Cut if off.Cover the spoke heads with rim tape. It's critical
that the spoke heads don't cut a hole in
your rubber rim liner. Standard cloth rim tape usually works well. Strapping
tape (tape with
fiber bands embedded) is strong enough to resist cutting by the spoke
heads.
Hint: A good combination is a layer of 1/2-inch strapping tape, worked down around each spoke
head, then one-inch electrical tape (plastic tape) overtop to add some
extra resistance to
sealant leaks.
Putting the rim liner into position.
Stick the valve stem in the hole, and stretch the rim liner onto the rim. It's OK if the area
with the valve stem sticks up a tiny bit (up to 1/8 inch) higher than
the surrounding rim strip.
But if the rim strip has to turn downward to reach the spot where the
tire's edge will sit,
or if there's a huge cavity under the rim liner, you may need to enlarge
the valve stem hole
a little more.
The rim liner must NOT interfere with the seating of the tire's bead on the rim.
Work around the rim, centering the rim liner so it touches the inner corner of the rim on both
sides, all the way around.
Putting the tire onto the rim. Make sure the bead seats correctly.
Now put your tire on. We're using a standard tire here. A larger-volume tire (diameter 2.0
or greater) is best for a tubeless system. Since you'll be running lower
pressure, you need
a larger volume of air to keep the rim from cutting the tire on those
roots and sharp rock
edges.
Hint: While you won't pinch-flat, you can
itself more easily when tubeless. I
recommend a 2.1 tire for most riders, and a 2.3 if you're a big guy doing
"major violence" while riding. Stan's no-tubes web site has a
list of
recommended
tires
. Look for thicker sidewalls, with plenty of rubber covering the
cords.
Soapy water brushed on, to detect leaks.
Brush soapy water or tire sealant around the rim, covering the edge of the rim strip, and the
bead of the tire. (For a first-time test inflation, use soapy water. Once
you've used the system
a while and predictably inflate your tire without problems, I recommend
that you brush tire
sealant onto the strip and tire bead. The tire will be immediately sealed
so you can hop on
and ride right away without leaks.)
Hint: To get a new just-out-of-the-box tire to seal, inflate it with an inner tube and let
it sit a few days. Then pull out the tube and try again.
Seating the tire's bead.
Work around the tire, forcing the bead out against the side of the rim. Using both hands, push
your thumbs down in the center of the tire, while your fingers drag the
sidewall of the tire
outward. When it looks like the bead is sitting against the sidewall (and
on the rim liner)
all the way around, you're ready to inflate.
Hint: If you can easily make out the details of the threads inside the tire sidewall of your
non-UST tire, it's probably too thin to make a good tubeless tire. Stan's
sealant can't help
you if the threads split apart in a thin tire sidewall.
Now comes the hard part.
Initial inflation is best done with a compressed-air source. If the fit between the rim liner
and tire bead is snug, you can get by with a good floor pump. (Don't even
DREAM of doing this
with a mini-pump! The air-flow is inadequate.) Spot leaky areas and drag
the tire sidewall
out against the rim in those spots. Keep pumping rapidly, constantly,
until you get the tire
bead to seal against the rim. Pump to around 40 PSI and check that the
tire will hold the pressure
for 20-30 minutes.
Hint: If you inflate your tire at the gas station, it must have a compressor tank. An electric
pump (the type you feed quarters into) won't do.
I like to seat the tire before adding the sealant.
Now it's time to add sealant. For an initial inflation, you need about 60 ml (2 ounces). You
can crack the tire away from the rim and pour it in...
Note: Some riders have alleged that Stans sealant may have contributed
to tire rupture. I don't think this should discourage you from using it.
Click
here to read more.
Hint: To avoid slow loss of tire pressure during the first day of riding, brush or rub a coating
of tire sealant around the bead of the tire before inflating it.
If you have a squirt bottle, this is a good way to get sealant in.
Or you can remove the valve core to put it in directly through the valve stem with a squeeze-bottle.
This is less messy. It may also maintain the seal between your rim and
tire, so re-inflation
is easier. Of course, you need a valve with a removable core.
Hint: Sealant should be replaced every couple of months, because it tends to gel up with time.
Using a squirt bottle to inject sealant.
Squirt the sealant in, then replace the valve core. Use a small wrench to tighten the core.
(If you finger-tighten only, the valve will be leaking in the middle of
your next ride!)
Hint: You can get 2-ounce squeeze bottles at a craft store. Cut the opening big enough that
the spout just barely fits into the stem (around 3 mm = 3/16 of an inch),
so "chunks" in the
sealant will pass into the tire without blocking the spout of the bottle.
Spreading the sealant around.
Now work the sealant around the tire. Holding the wheel horizontally, tip it slightly down,
then slightly up. Rotate the wheel about six inches, and repeat. Continue
until you've worked
all the way around the wheel a couple of times.
Hint: Particularly with standard
(non-tubeless) rims, some brands of non-UST tires may pop off the rim
when
you turn hard. You want thick sidewalls and thick bead -- a tire that's
a
little harder to get onto (and off of) the rim. See Stan's no-tubes list
of
recommended
tires
.
Tip upward and downward as you rotate the tire.
Turn the wheel over, and repeat the tip-down, tip-up process all the way around the wheel.
This gets sealant on the opposite bead of the tire.
A CO2 inflator.
Important notes!When you go tubeless, you need to invest in a CO2-powered inflator. Yes, you can add air using
a mini-pump. But if you're forced to take the tire off while in the woods,
you won't be able
to seal the tire without the power of a CO2 inflator. (A CO2 cartridge
has just enough air
to fill one tire. Pack more than one!)
Despite being tubeless, you should carry an inner tube in your kit. If disaster occurs, you
can take off the rim liner, stick the tube inside, and ride the bike.
