Nukeproof MEGA 290, Руководство пользователя, Страница: 14 / 19

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dangerous surfaces. These surfaces are
designed to add safety by increasing grip
between the rider’s shoe and the pedal. If
your bicycle has this type of high-performance
pedal, you must take extra care to avoid
serious injury from the pedal’s sharp surfaces.
Based on your riding style or skill level, you
may prefer a less aggressive pedal design or
chose to ride with shin pads. Your Authorised
Nukeproof Dealer can show you several
options and make suitable recommendations.
4.E.4. Toe clips and straps are a means to
keep feet correctly positioned and engaged
with the pedals. The toe clip positions the
ball of the foot over the pedal spindle,
which gives maximum pedalling power. The
toe strap, when tightened, keeps the foot
engaged throughout the rotation cycle of the
pedal. While toe clips and straps give some
benefit with any kind of shoe, they work most
effectively with cycling shoes designed for
use with toe clips. Your Authorised Nukeproof
Dealer can explain how toe clips and straps
work. Shoes with deep treaded soles or welts
which might make it more difficult for you to
remove your foot should not be used with toe
clips and straps.
Warning: Getting into and
out of pedals with toe clips
and straps requires skill which
can only be acquired with
practice. Until it becomes a
reflex action, the technique
requires concentration which
can distract your attention and
cause you to lose control and
fall. Practice the use of toe
clips and straps where there
are no obstacles, hazards, or
traffic. Keep the straps loose,
and don’t tighten them until
your technique and confidence
in getting in and out of the
pedals warrants it. Never ride
in traffic with your toe straps
tight.
4.E.5. Clipless pedals (sometimes called “step-
in” pedals are another means to keep feet
securely in the correct position for maximum
pedalling efficiency. They have a plate, called
a “cleat,” on the sole of the shoe, which clicks
into a mating spring-loaded fixture on the
pedal. They only engage or disengage with a
very specific motion which must be practiced
until it becomes instinctive. Clipless pedals
require shoes and cleats which are compatible
with the make and model pedal being used.
Many clipless pedals are designed to allow
the rider to adjust the amount of force needed
to engage or disengage the foot. Follow the
pedal manufacturer’s instructions or ask
your Authorised Nukeproof Dealer to show
you how to make this adjustment. Use the
easiest setting until engaging and disengaging
becomes a reflex action, but always make
sure that there is sufficient tension to prevent
unintended release of your foot from the pedal.
Warning: Clipless pedals are
intended for use with shoes
specifically made to fit them
and are designed to firmly
keep the foot engaged with
the pedal. Using shoes which
do not engage the pedals
correctly is dangerous.
4.E.5. Practice is required to learn to engage
and disengage the foot safely. Until engaging
and disengaging the foot becomes a reflex
action, the technique requires concentration
which can distract your attention and cause
you to lose control and fall. Practice engaging
and disengaging clipless pedals in a place
where there are no obstacles, hazards,
or traffic; and be sure to follow the pedal
manufacturer’s setup and service instructions.
Always try to disengage at least one foot
before stopping so you are prepared to set
a foot down for balance. If you do not have
the manufacturer’s instructions, see your
Authorised Nukeproof Dealer, or contact the
manufacturer for advice.
4 . F. T Y R E S A N D T U B E S
4.F.1. Tyres
Bicycle tyres are available in many designs
and specifications, ranging from general-
purpose designs to tyres designed to perform
best under very specific weather or terrain
conditions. If, once you’ve gained experience
with your new bike, you feel that a different
tyre might better suit your riding needs, your
Authorised Nukeproof Dealer can help you
select the most appropriate design.
The size, pressure rating, and on some high-
performance tyres the specific recommended
use, are marked on the sidewall of the tyre.
The part of this information which is most
important to you is tyre
pressure.
Warning: Never inflate a tyre
beyond the maximum pressure
marked on the tyre’s sidewall.
Exceeding the recommended maximum
pressure may blow the tyre off the rim, which
could cause damage to the bike and injury to
the rider and bystanders. The best and safest
way to inflate a bicycle tyre to the correct
pressure is with a bicycle pump which has a
built-in pressure gauge.
Warning: There is a safety
risk in using service station
air hoses or other air
compressors. They are not
made for bicycle tyres. They
move a large volume of air
very rapidly and will raise the
pressure in your tyre very
rapidly, which could cause the
tube to explode.
Tyre pressure is given either as maximum
pressure or as a pressure range. How a tyre
performs under different terrain or weather
conditions depends largely on tyre pressure.
Inflating the tyre 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. Tyre pressure that
is too low for your weight and the riding
conditions can cause a puncture of the tube by
allowing the tyre to deform sufficiently to pinch
the inner tube between the rim and the riding
surface.
Caution: Pencil type
automotive tyre gauges can
be inaccurate and should not
be relied upon for consistent,
accurate pressure readings.
Instead, use a high-quality dial
gauge.
Ask your Authorised Nukeproof Dealer to
recommend the best tyre pressure for the
kind of riding you will most often do and have
the Authorised Nukeproof Dealer inflate your
tyres to that pressure. Then, check inflation
as described in Section 1.C. so you’ll know
how correctly inflated tyres should look and
feel when you don’t have access to a gauge.
Some tyres may need to be brought up to
pressure every week or two. Some special
high-performance tyres have unidirectional
treads. Their tread pattern is designed to work
better in one direction than in the other. The
sidewall marking of a unidirectional tyre will
have an arrow showing the correct rotation
direction. If your bike has unidirectional tyres,
be sure that they are mounted to rotate in the
correct direction.
4.F.2. Tyre valves
There are primarily two kinds of bicycle tube
valves: The Schrader valve and the Presta
valve. The bicycle pump you use must have
the fitting appropriate to the valve stems on
your bicycle.
The Schrader valve is like the valve on a car
tyre. To inflate a Schrader valve tube, remove
the valve cap and clamp the pump fitting onto
the end of the valve stem. To let air out of a
Schrader 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 tyres. To inflate