Sizing Information

Adult Bikes

The following rules of thumb should be applied when you try a bike for size:

Racing Bikes: Standing flat footed on the ground, you should have a minimum of 1" clearance between yourself and the top tube of the frame.

Mountain Bikes: Standing flat footed on the ground, you should have a minimum of 3" clearance between yourself and the top tube of the frame.

A simple calculation can be used to estimate your required frame size if you are not able to sit astride a bike to measure:

Measure your inside leg measurement to the floor, subtract 3" (for mountain bikes, or 1" for road bikes) then subtract 10" (the average distance from the bottom bracket to the ground). This will give you the maximum frame size that you will need.

But buying a bike of the correct size is not just about the height from the ground. As bikes get bigger height-wise, they also get longer. The distance from the saddle to the handle bars increases by on average 1" for every 2" increment in frame size. So you must also make sure that though you may be able to stand astride a bigger framed bike, that you can still comfortably reach the handlebars and manage all the controls. Remember that the saddles on all bikes are adjustable by between 4" and 10" so any bike can be tailored to fit you perfectly.

Childrens Bikes

If the bike is for a child, they generally fall into age categories based on the average size of a child of a specific age. There is no hard and fast rule that says that you must buy a bike of a particular size for a child of a specific age. If the child is comfortable and not too stretched on the bike, and they can manage all the controls ie turn the handlebars safely, reach the brake levers and operate them AND touch the floor with the ball of their foot, then there is nothing to prevent you from selecting a bike in a bigger age category.

12" Wheel Cycles - Suitable for ages 2½ to 5
16" Wheel Cycles - Suitable for ages 5 to 7
20" Wheel Cycles - Suitable for ages 7 to 9
24" Wheel Cycles - Suitable for ages 9 to 11
26" Wheel Cycles - Suitable for ages 11+ (these are classed as adult cycles)

First Bikes: 12" wheels, suitable for average ages 3 to 5. Larger children may benefit from a 14" wheel cycle BUT these are generally made by toy manufacturers rather than genuine cycle manufacturers and tend not to last very long and are virtually impossible to get spare parts for.

Once a child has learnt to ride without stabilisers (generally about age 5) they will move up to a 16" wheel cycle. These do not normally come fitted with stabilisers but they can be added to virtually all 16" wheel bikes if required.

It is a very tempting thing to do, but don’t buy a bike which is too big for your child in the hope that they will grow into it. They will, but in the meantime they will be riding a bike which is not easy for them to control, which can be very dangerous. It does not really save money anyway, because if you change bikes more often, the outgrown ones will have a higher resale value.