Transport - Bicycles
Frame Materials and Frame Types
Alloy:
Confusingly, in the bike business alloy specifically means aluminium alloy. Aluminium tubes are thicker than
steel and so are easier for computer-controlled robots to weld. In addition, aluminium is also nice and shiny and
doesn’t rust, although road salt can affect the finish. As it is very stiff aluminium can feel harsh to ride, but
the newer quality alloys are addressing this problem.
Steel:
What bikes are traditionally made of. There are lots of different grades of steel used for making bikes. These
range from solid, but heavy exhaust pipe tubing to really high tech alloys, which are extremely light and
strong.
Steel is going out of favour because the cheaper material needs to be welded by humans, not machinery. It does,
however, provide many benefits for cyclists. Steel, for example, has a bit more of a spring in it than aluminium
and therefore will be less harsh to ride. Steel frames will rust, but if looked after could last a lifetime.
Furthermore, steel does not fatigue like aluminium.
Titanium:
The dream material! It is lighter than anything else, very strong, does not rust, does not fatigue and produces
a very responsive bike. So what’s the catch? Titanium, while relatively cheap by itself, is very difficult to cut
and weld, so titanium frames are expensive.
Carbon Fibre:
Also called a composite, this is a mixture of a matting of carbon threads and epoxy resin - like fibreglass but
using carbon threads instead of glass. Carbon fibre is strong and light and because the manufacturer can decide
which direction the fibres go, the frame can be made stiff in one direction and springy in another. Because all
these layers need to be bonded together properly though, it is expensive and it can also be quite delicate.
Magnesium:
This has been used for components and suspension forks for a while and is now starting to be used for frames. It
is lighter than aluminium but just as strong.
Hi-Ten:
Short for high tensile steel. Basically what your car, your washing-machine and your lawnmower are made out of.
It’s strong and durable.
Easy Entry Frame:
An IDEAL BIKES frame, engineered to provide easier access when getting on and off the bike. The frame has a
lower or dipped top tube.
Pulse Frame/Wave Frame/d-type Frame/Loop Frame/Low Step Frame/Easy Board frame:
Variations on IDEAL BIKES’ easy entry frame shape. Basically this allows for ease when getting on and off the
bike.
Diamond geometry frame:
Frame shaped like a diamond. Provides a fast and stable frame shape, popular with road bikes.
CarboFerric Steel:
If you’re a chemist, you’ll be laughing. Yes, all steel is carbo-ferric - it means that it has iron and carbon
in it. This is basically the same as Hi-Ten.
CrMo (a.k.a. ChroMo, Cromoly):
This is steel with some extra components added to make it stronger. This means that the bike manufacturers don’t
need to use as much of it and so makes the frame tubes thinner. Bikes made of this will feel lighter and more
lively to ride. More specifically it has Chromium and Molybdenum added to increase its tensile strength.
4130:
This is a type of CrMo - the number is a way of defining what extra things are added to the steel to make it
stronger.
501,525,531,653,725,753,853:
All types of bike steel made by the British company Reynolds. All are very good because they are specifically
designed for bicycles. As the number goes up, the sophistication of the alloy goes up and the bike gets lighter and
stronger - and more expensive of course!
6061, 7005:
These are grades of aluminium alloys used for making bicycles. Both are good, strong alloys.
Double-Butted:
Not a strange anatomical problem, but a method of making bikes lighter. The tubes are thick at the joints for
strength, but get thinner in the middle for weight saving. This is because the stress on the centre section of the
tube is lower than that at the ends where it is welded.
SST Rotor:
Component used on Ideal Bikes’ Freestyle 20" model. Allows freestyle bikers to do clean bar spins, a popular
freestyle trick.
Freestyle handlebar:
A handlebar designed specifically with freestyle models in mind. Allows for greater flexibility and movement
when doing tricks.
Carbon dropbar:
The drop bar is a handlebar designed for road racing bikes, allowing the rider to obtain an aerodynamic
position. Carbon is a strong and lightweight material that is great for road racing bikes.
Forks:
Suspension fork:
Suspension forks act as a shock absorber, providing energy savings through the absorption of minor bumps. For
mountain bikers, they also help to maintain control and speed on tricky descents.
Adjustable suspension fork:
As above, but the damping adjustment helps control the suspension's speed of travel or rebound. If you ride on a
terrain that has big bumps and ride at higher speeds, you'll want more damping. If you ride a terrain that has
frequent, smaller bumps, you'll want less damping –so the fork can travel quickly and be ready for the next
impact.
Suspension fork with preload adjustment:
This allows you to adjust or tune the spring rate to your weight. The spring rate is how much force is required
to get the spring moving. A heavier rider will require a higher preload adjustment than a lighter rider.
Rigid fork:
Non adjustable, non-suspension fork. Good for road use as it allows for maximum use of pedalling energy.
Carbon fork:
Carbon fibre is a strong and light material, allowing for a more durable fork.
Wheels:
Alloy Wheels:
All good bikes will have aluminium alloy wheel rims. They are lighter, don’t rust and the brakes work much more
efficiently than with steel rims.
Stainless Steel Spokes:
A mark of quality. Stainless steel spokes are not any lighter than the cheaper galvanised ones, but they do look
better and don’t rust.
Double-butted Spokes:
Like double-butted tubing, these are thinner in the middle where the extra metal is not needed. They are lighter
and are stronger than the normal ones (called "straight gauge").
Gears:
Derailleur Gears:
Derailleur gears work by having several different sized cogs at the front and back of the bike. It uses a cage
mechanism (the derailleur) to "derail" the chain from one cog to another. A simple mechanism, it works surprisingly
well and is light.
Derailleur systems are exposed to the elements so need a reasonable amount of maintenance. They can have 15, 18,
21, 24 or 27 gears, although there is quite a bit of overlap in the ratios.
Hub Gears:
Hub gears have a gearbox built into the rear hub, sealed away from the elements. Gears are engaged and
disengaged by a pushrod from the end of the hub. Hub gears are heavier than derailleurs, but need a lot less
maintenance and are more forgiving of misuse. They can have 3, 4, 5, 7 or 14 ratios, with no overlap between
them.
Gear Shifters:
Gear shifters are the controls on the handlebars which you use to change gear. Nowadays, almost all of them are
indexed. This means they click into gear and you don’t have to guess how far to move them. They come in three basic
types:
Thumbshifters – Road bikes use a shifting combination mounted onto the handlebar - push them one way to go up a
gear, push the other way to go down.
Pushbutton shifters – Shimano calls this marvel of biking technology "STI" System Total Integration. These use
two buttons or levers, usually one for your thumb and one for your index finger. Push with your thumb to go up a
gear, push with your index finger to go down.
Twist shifters - ("Gripshift", "Revoshift") With these, you twist a section of the handlebar grip to change
gear.
Nexus 3 speed coaster:
A brand of gears used by Ideal Bikes for a number of models. A 3-speed coaster is ideal for those who require a
bike for riding around town.
Shimano 7 speed/6 speed coaster:
A great brand of gears used by Ideal Bikes for a number of models. Similar to a 3-speed, 6-speed and 7-speed
coasters are great for around town, but offer an option for more hilly terrains.
Brakes:
Rim-mounted Brakes:
These are brakes which work by squeezing the wheel rim. There are three main types:
V-type or Cantilever - These have two arms fitted to the frame or fork, pulled together by a cable strung
between them. V-types have long arms and one cable that pulls across the top of the tyre.Cantilevers have shorter
arms and a Y-shaped cable which pulls upwards. Both types are very powerful and are found on mountain bikes and
many other types of bike.
Callipers - These are like pincers, so pulling the cable makes them clamp onto the rim. They are not as powerful
as V-type or Cantilever, but the new "Dual Pivot" ones come very close. Callipers are mainly found on racing
bikes.
All rim brakes have the advantage of being light.
Hub-mounted Brakes:
These work at the hub, not the rim, and fall into two types:
Disc - These have an exposed steel disc at the hub, which is clamped by a small calliper. Discs can be very
powerful and are also pretty light. They are exposed to the elements, but because they are further from the road
they are less affected by mud and water. Discs are popular on mountain bikes because they are so powerful.
Drum (a.k.a Hub) - These have a sealed drum at the hub, with two expanding brake shoes inside. They are not as
powerful as discs, but are completely sealed against the elements. They are heavier than other types of brake and
are often used on city bikes because of their very low maintenance.
Hydraulic Brakes:
Most brakes are operated by pulling a steel cable, but hydraulic brakes work more like those in a car, using
pistons to compress oil which then transmits the force. Hydraulics have lower maintenance than cables, which can
get gummed up with mud or rust. They are also very powerful as they multiply the force of your hand. Hydraulics are
available to operate on the rim (like cantilevers) or as disc brakes. Hydraulics are more expensive than
cable-operated brakes and require expert treatment if they go wrong.
Tektro alloy u-brakes and levers:
A brand of brake component used by Ideal Bikes on the Freestyle range. Named ‘U-brakes’ due to the shape (For
levers see below).
Brake Levers:
Road bikes use a shifting and braking lever combination mounted onto the handlebar. Basically, all it means is
that the rider can brake without moving his or her hands off the handlebar.
Components:
Groupset:
The groupset refers to the gearing and braking components of the bike. A groupset will consist of the crankset
(also called chainrings or chainwheels), bottom bracket, front and rear derailleur, cassette, chain, front and rear
wheel hubs, gear shifting/brake levers and brake set. Some of the higher end groupsets will include components such
as a seat post, handle bar and stem, head set and pedals.
Crankset (also called chainrings or chainwheels):
There are two versions of crankset; double chainring and triple chainring. Chainrings are classed by the number
of teeth they have e.g. 53 teeth on the large chainring and 39 teeth on the smaller chainring. Common sizes are
52-39, 53-39, 53-42 and 52-42 for double cranksets and 52-42-30 and 53-39-30 for triple cranksets. You will find
that most entry level bikes come with a standard 53-39 crankset.
Bottom Bracket:
The axle and bearing assembly around which the crankset revolves.
Front and rear derailleur (or derailer):
The front derailleur moves the chain from one chainring to another. The rear derailleur moves the chain from one
sprocket to another.
Chain:
Probably the most neglected component on a bicycle. Modern bicycles use roller chains (the chain is made up of a
bunch of small rollers linked together).
Wheel hubs:
The axle and bearing mechanism around which the wheels revolve. The rear wheel hub incorporates a "freewheel" or
"freehub", which allows the wheel to continue turning without needing to pedal (called "freewheeling" or
"coasting").
Cassette:
A combination of gears (or sprockets) combined together to form a cluster or cassette. As with chain rings,
cassettes are classed by the total number of sprockets installed on the cassette e.g. a 9-speed cassette will have
9 sprockets.
Each sprocket will have a different number of teeth. Sprockets are combined together to form different gearing
ratios. A typical example will be a cassette with sprockets starting off with 12 teeth, then 13, 14, 15, 16, 17,
18, 19 and 21 teeth.
Older cassettes had 6 or 7 sprockets, while newer models have anything up to 10 sprockets.
Other Parts:
Adjustable stem:
The stem is the bar that connects the handlebars to the main frame. An adjustable stem allows the height of the
handlebars to be altered according to preference.
Adjustable suspension seat:
Allows you to alter the height of the seat, according to preference. A suspension seat is used mostly on city
bikes and is the ultimate in providing a comfortable ride.
Ritchey clamp:
Component used on Ideal Bikes’ road bike models. The clamp attaches the handlebars to the main frame. Ritchey
clamps are used due to their ability to reduce stress on lightweight bars.
SKS mudguards:
A brand of mudguards fitted on a select number of Ideal Bikes’ models. They are a great protector from your
tyres’ water and mud spray. In addition, because they are made from a hard wearing and shock resistant material
they are extremely durable.
lighting:
Brand of lighting set used on a select number of Ideal Bikes’ models. Dynamo lighting is an effective form of
lighting for any type of bike, keeping you safe whilst riding at night or in foggy, wet weather conditions.
Kendra krackpot tires:
Brand of tyre used for Ideal Bikes’ Freestyle model. KrackPot offers greater cornering and a lean angle and
control for flatland and freestyle. The wrap-around tread design is durable and great for grinds.
ADD YOUR OWN JARGON TO THIS SECTION:-
|