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d.
Replacing a tube or tire
Read the previous sections a. and b. to learn how to remove and replace the front and rear wheel. You will need to
understand how to remove the wheel prior to replacing a tube or tire. This section only explains how to remove the
tire from the rim and how to replace a tube.
Before explaining how to replace a tube and tire, details on the G Plus Mariner 7’s tubes and tires are discussed.
Tubes and tires are 2 of the most important components on your new bicycle and must always be in optimum
condition. It is important you understand about the tubes and tires used on your bicycle.
The G Plus Mariner 7 uses high-performance KENDA Low Resistance UNI-Directional tires with a 40-65 PSI rating.
Bicycle tires are available in many designs and specifications, ranging from general-purpose designs to tires
designed to perform best under very specific weather or terrain conditions. If, once you’ve gained experience with
your new bicycle, you feel that a different tire might better suit your riding needs; your dealer can help you select
the most appropriate design.
The size, pressure rating, and on some high-performance tires the specific recommended use, are marked on the
sidewall of the tire. The part of this information, which is most important to you, is Tire Pressure.
The best and
safest way to inflate a bicycle tire to the correct pressure is with a bicycle pump that has a built-in pressure gauge.
WARNING:
Never inflate a tire beyond the maximum pressure marked on the tire’s sidewall.
Exceeding the recommended maximum pressure may blow the tire off the rim, which could cause damage
to the bike and injury to the rider and bystanders.
WARNING:
There is a safety risk in using gas station air hoses or other air compressors. They are
not made for bicycle tires. They move a large volume of air very rapidly, and will raise the pressure in your
tire very rapidly, which could cause the tube to explode.
Tire pressure is given either as maximum pressure or as a pressure range. How a tire performs under different
terrain or weather conditions depends largely on tire pressure. Inflating the tire to near its maximum recommended
pressure gives the lowest rolling resistance; but also produces the harshest ride. High pressures work best on
smooth, dry pavement. Very low pressures, at the bottom of the recommended pressure range, give the best
performance on smooth, slick terrain such as hard-packed clay, and on deep, loose surfaces such as deep, dry
sand. Tire pressure that is too low for your weight and the riding conditions can cause a puncture of the tube by
allowing the tire to deform sufficiently to pinch the inner tube between the rim and the riding surface.
CAUTION:
Pencil type automotive tire gauges can be inaccurate and should not be relied upon for
consistent, accurate pressure readings. Instead, use a high quality dial gauge.
Ask your dealer to recommend the best tire pressure for the kind of riding you will most often do, and have the
dealer inflate your tires to that pressure. Then, visually check inflation by sitting on the saddle with your weight and
noticing your tires response. You should also squeeze tires and feel resistance so you’ll know how correctly
inflated tires should look and feel. Some tires may need to be brought up to pressure every week or two. Other high-
performance tires may also have unidirectional treads, similar to the factory tires on your G Plus Mariner 7: their
tread pattern is designed to work better in one direction than in the other. The sidewall marking of a unidirectional
tire will have an arrow showing the correct rotation direction. When replacing your tires with tires that are
unidirectional, be sure that they are mounted to rotate in the correct direction.
There are primarily two kinds of bicycle tube valves: The Schraeder Valve and the Presta Valve. The bicycle pump you use must
have the fitting appropriate to the valve stems on your bicycle. The G Plus Mariner 7 uses Schraeder valves. The Schraeder valve
is like the valve on a car tire. To inflate a Schraeder valve tube, remove the valve cap and clamp the pump fitting onto the end of
the valve stem. To let air out of a Schraeder valve, depress the pin in the end of the valve stem with the end of a key or other
appropriate object. The Presta valve has a narrower diameter and is only found on bicycle tires. To inflate a Presta valve tube
using a Presta headed bicycle pump, remove the valve cap; unscrew (counterclockwise) the valve stem lock nut; and push down
on the valve stem to free it up. Then push the pump head on to the valve head, and inflate. To inflate a Presta valve with a
Schraeder pump fitting, you’ll need a Presta adapter (available at your bike shop) which screws on to the valve stem once you’ve
freed up the valve. The adapter fits into the Schraeder pump fitting. Close the valve after inflation. To let air out of a Presta valve,
open up the valve stem lock nut and depress the valve stem.
WARNING:
Patching a tube is an emergency repair. If you do not apply the patch correctly or apply several patches, the tube
can fail, resulting in possible tube failure, which could cause you to lose control and fall. Replace a patched tube as soon as possible.
To remove a tire or tube, follow these instructions (you will need to use the tire levers included with your multi-use
tool kit.
DEPENDING ON ACCESSORIES INCLUDED, THE LEVERS MAY NE SEPARATE AND NOT PART OF THE MULTI TOOL
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Summary of Contents for G Plus Mariner 7
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