SIZING & POSITIONING GUIDE
SIZING (ROAD BIKES)
Using the traditional method 9 to 10 inches is deducted from the inside
leg measurement taken in stocking feet. For example an inside leg
measurement of 30 inches would have 9 or 10 inches deducted so a frame of
20 or 21 inches would be recommended.10 inches would be deducted, when the
seat tube finishes level with the top tube and is measured to this point.
9 inches would be deducted, when the seat tube extends above the top tube
by an inch or so as it does with current aluminium frames.
As a very rough guide the following sizes apply:-
HEIGHT
|
FRAME SIZE |
5 ft 3 ins to 5 ft 5 ins |
19 to 20 inch |
5 ft 5 ins to 5 ft 7 ins |
20 to 21 inch |
5 ft 7 ins to 5 ft 9 ins |
21 to 22 inch |
5 ft 9 ins to 5 ft 11 ins |
22 to 23 inch |
5 ft 11 ins to 6 ft 1 in & over |
23 to 24 inch |
6 ft 1 in & over |
24 to 25 inch |
SIZING (ATB BIKES)
An additional 3 to 4 inches are deducted from the above figures for ATB
frames
POSITIONING:
SADDLE HEIGHT
Set one crank vertical so that the pedal is in the lowest position,
then place the shoed heel of your foot on that pedal. The saddle should be
adjusted up or down till there is a slight bend at the knee. It should be
possible to place both heels on the pedals and pedal backwards without
rocking from side to side on the saddle.
NB Knee problems may be caused by having a top of saddle to pedal
dimension of more than 110 % of the rider’s inside leg measurement.
SADDLE LATERAL POSITION
Set the cranks horizontal, while sitting properly on the saddle, then
place one shoed foot on the forward pedal so that the ball of that foot is
on the pedal spindle centre line. A plumb line held just behind the knee
cap should pass through the pedal spindle centre line. The saddle should
be loosened & moved backwards or forwards to achieve this position.
The top of the saddle should always remain horizontal. This check must be
carried out on a level surface. This represents the best position for
riding on flat roads. Easing forward in the saddle when going uphill &
backwards when going downhill is possible & gives the rider an
acceptable level of stability.
HANDLEBARS (ROAD BIKES)
The stem needs to place the handlebars 1 to 2 inches below the top of
the saddle & 1 to 2 inches plus the forearm with extended fingers from
the nose of the saddle. To do this place the elbow against the nose of the
saddle & extend the forearm & fingers parallel to the top tube
towards the handlebars. A gap of between 1 & 2 inches should exist
between your fingers & the handlebar. 1 inch gives a general riding
position & 2 inches a more competitive position.
The position you have achieved is a good starting point.
Tourists tend to sit further back, lower down & with the handlebars
up a little.
Sprinters generally sit higher & further forward with handlebars
down a bit.
HANDLEBARS (ATB BIKES)
For general riding, a position where the handlebar grips are placed 1
inch below the top of the saddle & 1 inch in front of the extended
fingers suits most people. See section above for Road Bike Handlebars for
details.
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