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Choosing
a Bike
Firstly 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 Bike
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.
| 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 |
52.5 |
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 (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. |
