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Wheel
Size
Larger wheels such as the 26” or 27” are used
in bike races, road riding and mountain biking because they
can increase speed with less work than smaller wheels. Larger
wheels also do better in turning corners because they have
longer contact with the pavement and therefore hug the road
better without slipping.
Neither the 26” or the 27” is better than the
other. Each has its advantages and disadvantages. What it
really comes down to is the comfortability of the rider
on the bike. The 26” is generally used for shorter
persons where as the 27” is generally used for taller
persons. One advantage of the 26” is that with smaller
size comes less weight and better acceleration. Riding at
a constant speed, though, the two are equally good.
Smaller wheels such as the 8”, 12”, 16”
and 20” are not as stable as larger wheels, but they
allow for better maneuverability. Any combination of two
sizes can increase control and/or speed. Small wheels and
even small wheel-large wheel combinations have been shown
to ride as well as a bike with larger wheels, but on paved
terrain.
Frames
High
Tensile Carbon Steel
Mountain bikes and all-purpose bikes are generally made of
steel because of the strength and durability. Steel is heavy,
and in this case is good because the weight will help keep
the rider and bike grounded when riding over rocky terrain.
Steel is in a way a form of suspension when compared to aluminum
alloy because steel absorbs some shock. A steel bike is more
comfortable to ride than an aluminum alloy bike. Steel has
slight bending capabilities; for instance a bent derailleur
from harsh riding can be bent back into shape.
Aluminum
Alloy
Do not confuse aluminum alloy for aluminum. Aluminum itself
is too soft to be used for building a bike, but aluminum
alloy works great. Aluminum alloy is aluminum combined with
another element such as magnesium, copper or silicon. Road
bikes are generally made of aluminum alloy because they
are meant to ride long distances. Aluminum alloy is strong,
lighter than steel and is quite stiff. This stiffness is
good and bad. For long rides a stiff bike requires less
energy because all the energy exerted on the pedal is transferred
directly to the wheel for increased power. The down side
to stiffness is the comfortability of the bike ride. Aluminum
alloy does not ‘give’ at all. Every crack, bump,
rock, pebble or slight difference in terrain is felt when
riding the bike. Steel has slight bending capabilities,
but aluminum alloy does not. Aluminum alloy will break,
but not bend. It is commonly used in the construction of
bikes because it is strong, light and less expensive than
steel. Aluminum alloy frames have a larger diameter because
the larger the diameter the greater the strength. A larger
diameter allows for a thinner wall and that in turn requires
less material for a lighter bike.
Tungsten
Inert Gas and Argon Welding
Welding for bikes is the process of joining frame tubes. Efun’s
bikes are welded using tungsten inert gas and argon. In tungsten
inert gas welding an electric arc is established between a
tungsten electrode and the part to be welded. To start the
arc an alternating current is used to break down the oxide
layer of the material. The current is then transferred through
the electrode to create an electrode arc. The metal (in our
case steel or aluminum alloy) to be welded is melted by the
intense heat of the arc and fuses together either with or
without a filler material. The arc zone is filled with an
inert gas to protect the tungsten electrode and melted material
from oxidation and to provide a conducting path for the arc
current. The shield gas used here is argon, which is normally
chosen according to the material type to be welded.
Tire
Pressure
Road bikes have narrow tires while mountain and all-purpose
bikes have wide tires. A mistake often made is in inflating
the tires. Many factors contribute to inflating to the correct
pressure. Certainly do not go beyond the minimum or maximum
as printed on the sidewall of the tires. Often times the mistake
is to overinflate wide tires and underinflate narrow tires.
Road bikes are meant for long rides, and the goal is to expend
as little energy as possible to last the whole ride. Underinflating
the tires provides a larger contact surface area with the
ground therefore creating more friction and requiring unnecessary
energy from the rider. Overinflating wide tires is bad for
mountain bikers because it transfers every obstacle on the
ground to the rider. Deflating the tires a little allows the
tire to conform to the terrain and provide a more comfortable,
less bumpy ride. Inflate the tires according to the terrain
conditions. For flat surfaces inflate to nearly maximum pressure
and deflate accordingly as the surface conditions get more
harsh.
How
to Choose the Right Bicycle Pump
Whether you ride often or little, cross country, on streets,
or over long distances, you should carry a bike pump and a
tire repair kit in case your tire goes flat. Different types
of riding require different types of pumps. Pumps come in
three main styles: mini, frame-fit and floor. Choose a pump
that suits your needs and is compatible with your bike. Generally,
the lighter the better. First consider the types of riding
you will be doing. For road riding, look for the lightest
weight pump that can handle your tire pressures. For mountain
or road racing, look for a design that you can inflate quickly.
For riding near your home, you might think about a floor model
that you can use for other uses around the house. You should
also compare pump performance. You can measure the amount
of work it takes to operate the pump, the amount of air the
pumps pushes out, and the maximum of amount of pressure the
pump can create in a tire. Therefore you need to consider:
1. Stroke
Force: Measures how hard you have to work to operate
the pump.
2. Strokes
to Inflation: Measures how much pumping you will have
to do to fill the tire.
3. Maximum
PSI Output: Measures the maximum amount of air pressure
the pump can push into the tire.
You should also check for compatibility of the pump with your
bike. Check all the mounting hardware and make sure it will
fit on your bike in such a way to be out of the way, and that
it fits in a position that is out of the way of other accessories.
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