Buying a bike - adults and children
The
most important thing when purchasing a bike is to get the size and fit
right - otherwise you will find you ache on longer rides, and lose
enthusiasm for cycling very quickly. Riding the most expensive bike in
the world will not be fun if it is the wrong size for you. As a quick
starting point:
With your feet 20 cm apart measure the distance from the crotch to the
floor (you will need some help here!) Advice: find
a big hardback book and push it up between your legs, while the other
edge of the book is held square against a wall. Make a pencil mark on
the wall at the top of the book, then measure from the floor to the
mark (repeat three times for an average). Not very elegant but pretty
accurate.
- Multiply this measurement by 0.67
That
should be a good estimate of the frame size from the centre of the
bottom bracket - the part where the pedal arms (cranks) join the bike
frame to the top of the seat post (the part where the saddle enters the
frame). (Some bikes have a different geometry (eg sloping top bar) and
will be measured differently - your shop or online supplier will make
this clear.
Having
bought the correct size bike (use the bike sizing chart
here
for added confidence)there is a lot of flexibility for making further
adjustments. The saddle height and position is much the most important
adjustment to make.
First,
make sure your saddle is horizontal.
Children's bikes
Get a bike with aluminum rims instead of steel or alloy. In addition to being stronger and lighter, they're more abrasive. This allows the brake pads more gripping traction, which makes for less slipping and quicker stopping.
Watch the different sizes in the different brands of bikes; children's bikes measure only the wheel size and not the frame size. Your child needs to be able to stand over the top tube with their feet flat on the ground for balance.
Keep in mind that the move from a bike without gears and backpedal brakes to one with more advanced components can take a little practice. A bike with 24 inch wheels and eighteen gears might be a little daunting.
