Merida City Bikes, Руководство по эксплуатации

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54
a
b
c
d
The wheels and the tires
The wheel consists of the hub, the spokes and the rim.
The tire is mounted onto the rim so that it encases the
tube in the case of the most common system, i.e. the
clincher or folding tires. There is a rim tape running
around the rim well
(a) to protect the sensitive tube
against the edges of the rim trough, which are often
sharp.
Another common system comprises tubeless tires
which require specific rims without boreholes and firmly
screwed valves. In addition, there are in rare cases tubu-
lar tires which are glued on specific rims.
The wheels are subjected to considerable stress through
the weight of the rider and any carried baggage as well
as through bumpy road surfaces and terrain. Although
wheels are manufactured with great care and delivered
accurately trued, spokes and nipples can lose a little
tension on the first kilometers. Ask your MERIDA dealer
to check and true up the wheels after you have bedded
them in over about 100 to 300 kilometers or 5 to 15
hours of use.
After the bedding-in period, check the wheels regular-
ly. It will, however, rarely be necessary to tighten the
spokes
(b)
.
A
Truing (retruing) wheels is a difficult job
which you should definitely leave to your
MERIDA dealer.
I
Tubular and tubeless tires will not be consid-
ered any further in the following. Read the
operating instructions of the rim manufactur-
er, the tire producer and the glue supplier and ask your
MERIDA dealer for advice.
Tires, inner tubes, rim tape, inflation pressure
The tires should provide grip and traction. At the same
time they should run smooth and enhance the rider’s
comfort by absorbing small shocks. Both the rolling
friction and the grip depend on the nature of the tire
carcass, the rubber compound and the tire tread. Your
MERIDA dealer would be glad to help you choose from
the numerous types of tires
(c)
.
If you want to mount a new tire, you need to mind the
sizing system and the actual size of the old tire. The lat-
ter is specified in two different units on the side of the tire.
One of the sizes is the standardized size in millimeters
which is more precise, e.g. the number sequence 40-
622
(d) means that the tire is 40 mm in width when ful-
ly inflated and has an inner tire diameter of 622 millime-
ters. The other size is indicated in inches (e.g. 28x1.5”).
The tires must be inflated to the proper inflation pressure
to provide an optimal compromise between smooth run-
ning and riding comfort. Properly inflated tires are also
more resistant to punctures. An insufficiently inflated tire
can easily get pinched (“snakebite”), when it goes over
a sharp kerb.