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First you must decide what type of
riding you are going to do. Will it be on the roads or
off-road? Will it be for racing, touring, or commuting?
If it is for racing, what kind of racing will you be
doing - road racing, track racing, time trialling or
mountain bike racing?
Mountain bikes
90% of the mountain bikes sold in
this country are never ridden off road. Most are used
for commuting or just sit in the shed. If you are going
to use it regularly off road then there is nothing
better than a mountain bike for this purpose, however
they are heavy and unresponsive when used on the roads.
If you only want the one bike but you also wish to
commute, then a second pair of tyres with a narrow,
slick tread can make a big difference to the performance
of the bike. You may even consider having a second set
of wheels built especially for this purpose. These tyres
give the added benefit of better handling and grip than
knobbly mountain bike tyres on wet tarmac.
Road Bikes
Do you intend to race, commute, tour,
or a mixture. A good compromise for all three is to
purchase a winter training bike. This will have a
reasonably light weight and responsive frame, narrow
wheels and room for mudguards, The advantage with this
type of bike is that the mudguards can be removed and
narrower tyres fitted for racing without sacrificing too
much performance in comparison to a purpose built racing
machine. Alternatively carriers for saddle bags and
panniers can usually be added and the gears adjusted for
touring.
Purpose built touring bikes will tend
to have larger clearance for mudguards and larger tyres,
a wider range of gears, and the carriers already fitted;
whereas racing bikes will have narrower tyres, higher
gears and close clearances.
If you intend to race but are not
sure what you kind, a road racing bike is a good first
option as tri-bars can be added for time trials or
triathlons, and then removed for road races (you are not
allowed to use them in bunched races).
Custom built or off the peg?
Most bikes bought by novice cyclists
are already built up with all its components, however
you may wish to go for a custom built bike. Buying off
the peg is usually cheaper than buying a frame and
components individually, however there are often some
cost saving items the manufacturer has included that may
have to be replaced within a short time. A custom built
machine gives you the opportunity of having exactly what
you want.
Go to a reputable dealer and get
advice. If you are unsure about what to buy, ask someone
in the club to come along with you.
Frame
The frame is the heart of a good
bike. Look for a bike with a good frame, even if the
rest of the equipment is not as good. Remember that the
components can always be upgraded at a later date.
Steel
The most common material for a frame
is steel. Look for a frame that is made from a steel
alloy such as Chrome Molybdenum (CroMo) or Manganese
Molybdeneum (MangMoly). Most of the frames you should be
looking at will say which company manufactured the frame
tubes (as opposed to who constructed the frame). Names
to look out for include Reynolds, Columbus, Dedeccai,
Vitus, Oria and Tange.
Alternatively you can go to a specialist frame builder
who will build one up to fit your measurements and
specifications. There are few frame builders who have
the technology to build in anything other than steel or
aluminium.
Steel has the advantage of being
sturdy, responsive yet forgiving on rough roads, can be
repaired by a frame builder quite easily in the event of
accidents, and probably represents the best value.
Aluminium
Aluminium frames are the next most
common. They can be lighter than steel but are usually
more expensive. They can also be made stiffer than steel
through the use of larger diameter frame tubes (which
increases the fatigue life compared to narrow aluminium
tubes) but this can make for a harsh ride on rough roads
or tracks. They will require specialist knowledge to
repair them however. Many aluminium frames now include
carbon fibre front forks and seat stays.
Carbon Fibre
These can be made either from either
tubes or a monocoque (e.g. Chris Boardman’s “Lotus”).
They can be very light but also very expensive. They
tend to be reserved for top of the range racing bikes.
Titanium
Titanium is expensive and difficult
to work with but is also very light and stronger than
aluminium. It also has a natural spring that makes it
more forgiving than aluminium. Again these frames tend
to be for top end racing bikes.
Frame Sizes
Having the correct size of frame
makes for a good position on the bike, and therefore a
more comfortable ride.
Frame sizes can be specified in
either inches or centimetres. If the frame size is in
inches, then this is usually the measurement from the
centre of the bottom bracket to the top of the seat tube
(or ‘centre to top’). Continental frame sizes are given
in centimetres and are usually measured from the centre
of the bottom bracket to a point in line with the centre
of the top tube (or cross bar) (‘centre to centre’).
However to complicate matters, some British frames are
also measured in centimetres but from centre to top! It
is always worth checking how the frame is measured
before buying or ordering.
The top tube length is always centre
to centre.
Another complication is that many
frames now have 'compact' geometry where the seat tube
is shorter than usual and the top tube slopes down to
the rear. This gives a smaller and therefore stiffer
rear end. Ask the dealer to give you the virtual
measurements of the frame - i.e. as if the top tube was
horizontal.
The following table gives a rough
guide to the size of road frame you should buy.
Inside leg is measured from crotch to
the ground.
| Inside
Leg |
Seat
Tube |
Top
Tube |
| Inches |
Cm |
Inches |
Cm |
Inches |
Cm |
| (C to
T) |
(C to
C) |
| 29 |
73.5 |
19.0 |
47.0 |
19.0 |
48.5 |
| 30 |
76.0 |
20.0 |
49.5 |
20.0 |
51.0 |
| 31 |
78.5 |
21.0 |
52.0 |
20.5 |
52.0 |
| 32 |
81.5 |
22.0 |
54.5 |
21.0 |
53.5 |
| 33 |
84.0 |
23.0 |
57.0 |
22.0 |
56.0 |
| 34 |
86.5 |
23.5 |
58.5 |
22.5 |
57.0 |
| 35 |
89.0 |
24.5 |
61.0 |
23.0 |
58.5 |
| 36 |
91.5 |
25.0 |
62.5 |
23.5 |
59.5 |
| 37 |
94.0 |
25.5 |
63.5 |
24.0 |
61.0 |
| 38 |
96.5 |
26.0 |
64.5 |
24.5 |
62.0 |
However these sizes are only a guide
and as everyone is different, then you may need to adapt
accordingly, either by having a frame custom built or by
varying saddle height and handlebar extension length.
With mountain bike frames however,
sizing is more difficult and will depend more on rider
‘feel’ than on any hard and fast rules. The length of
the top tube is more critical than the seat tube length
(as mountain bike seat pillars are longer and therefore
have more adjustment). The longer the top tube, the more
stretched out you will be on the bike. Novice riders
tend to prefer to be more upright and so will require a
shorter top tube whereas a racing mountain bike’s will
be longer. Also look for a frame that will give you at
least 2 inches clearance between crotch and top tube
when standing astride the bike.
Alternatively you may wish to have a
computer program calculate the size of frame for you.
Certain cycle shops operate the Bioracer computer system
(http://www.bioracer.com ). The shop assistant will take
certain critical measurements from you (e.g. height, leg
length, etc.) and send them to Bioracer. The Bioracer
computer program will then calculate all the dimensions
of the bike (seat tube, top tube etc. ) right down to
the crank length, and saddle height, depending on the
type of riding the bike is designed for. This is good
way of avoiding any trial and error in setting up the
bike although you will pay a fee for this. |