MADE BY NITYANT

3. Without math, bicycling cannot exist.
Geometric figures are used in the construction of a
bicycle. Wheel circumferences and frame angles are
calculated using math, so the rider could select the right
bicycle.
Could you imagine a bike with
square or even octagon
wheels? A shape other than a
circle has edges and would
create bumps and friction.

4. The force used by pedalling allows the gears of a bike to spin
the back wheel. As the back wheel rotates, the tire uses
friction to grip the surface and move the bike in the desired
direction.
A cyclist uses different gear combinations for different
terrains. How is the right gear combination calculated?

5. Gear ratio and speed
speeds
mph
revolutions per minute
60
(steady
pedalling)
120
(very fast
pedalling)
ratio 1
2
3
4
4.95
9.9
14.85
19.8
9.9
19.8
29.7
39.6
The speed of the bike is determined by the gear ratio, the
size of the wheels and how fast the pedals are turning
A cyclist is in a gear with a ratio of 4.
The bike has wheels with a 2m circumference.
They are pedalling at 50 revolutions per minute.
What is their speed in miles per hour?
Distance travelled by wheel in 1 hour = wheel circumference x revolutions per hour x gear ratio
Distance travelled
by wheel in 1 hour = 2 x 50 x 60 x 4
= 24000m
≈ 15 miles
1 mile ≈ 1600 metres
using the different gears and varying
your pedalling speed enables you to
reach a range of speeds:
of course, you can only reach the
higher speeds if have the power to
pedal very fast in a high gear...