Bike Frame Sizing and Fitting Guide


Your bike size is important to get right as, just like shoes,
the same size in one brand might be different to another. Too big
and you'll fight to stay in control, too small and you'll find
yourself with a sore back, bum or knees by the end of a ride.
Unless you know your exact fit, it can be hard to know which bike
to go for online, or how to set up your dream bike after buying via
the web. If you are in any doubt, head to your nearest bike shop,
ride the bikes of your choice and benefit from their staff's expert
fitting advice.
If possible try at least three of four similar sized bikes from
different manufacturers to compare the reach (distance between you
and the handlebars) and if possible the ride too. Before trying any
bikes make sure you raise the saddle to the correct
height. You'll probably have an idea which feels most
comfortable / suits your needs best but if it isn't clear cut
the following step-by-step bike fit guides should help.
Step-By-Step Bike Fit Guides
Road
Bikes
Commuting
/ Town / Hybrid Bikes
Professional Bike Fit
It's not just pro riders who benefit from a professional bike fit. For anyone who enjoys riding their bike regularly a well-fitting bike will make you faster, more efficient, increase your comfort and reduce your chance of knee, back or arm injury.
The Bike List paid a visit to Andy Brooke from Bike Science in
Derby to find out if their level 2 fit is worth the £175 price tag.
Bike Science recommend this level of fit for people who "already
have a bike and are looking to optimise their position for best
comfort and power output."
Click here
to read more...
Beat back ache on a bike
Suffering from back ache whilst riding? Read our guide on how to beat it.
Frame Sizes
For normal adult sized 26" wheels (or 700C road / hybrid bike
wheels), size is determined by frames size (kids bikes are
determined by wheel sizes with appropriate age ranges
attached).
Frame size is measured from the top where the seat post slots in,
down to the bottom bracket (the centre of the axle carrying the
pedal arms). In the UK and USA this is measured in inches, while in
Europe it is often in centimetres. Some sizings can be different as
manufacturers measure from different places, such as from the
middle of the top tube intersection and the seat tube. If in doubt
ask the manufacturer where the measurements are taken from, or take
a tape measure with you to the shop.
Frame Size | Inside leg (minimum size) | Person Size |
22"-23" | 32"+ | 6ft + |
20" | 29" | 5ft 10" |
18" | 27" | 5ft 6" |
16" | 25" | 5ft 4" |
14" | 23.5" | 5ft 2" |
Sizing your bike
Road / Racing Bikes
Stand flat footed on the ground and look for a minimum of 1"
between yourself and the top frame tube.
Mountain Bikes
Stand flat footed on the ground and look for a minimum of 3"
between yourself and the top frame tube.
Can't try the bike for real?
Here's how to estimate your frame size without having to sit on
the bike.
1. Measure your inside leg measurement to the
floor (wearing the shoes you would wear for biking)
2. Subtract 3" for a mountain bike or 1" for a
road bike
3. Subtract a further 10" (the average distance
from the bottom bracket to the ground). This figure is the maximum
frame size you'll need.
As bikes get bigger height-wise, they also get longer, so make
sure that you can still comfortably reach the handlebars and manage
all the controls. Get a bike too big for you and it can be
dangerously difficult to control. The distance from the saddle to
the handle bars increases by an average of 1" for every 2" increase
in frame size. Saddles are adjustable by between 4" and 10" and
handlebars can be moved up and down, elongated or shortened so you
can tailor the bike to fit you perfectly.
Kids
Kids bikes are usually grouped into age categories, but there's
no need to stick to it rigidly and force your tall 6 year old on to
a 6 year old's bike. If your little Johnny or little Suzie feels
comfy and not too stretched out while sitting on the bike with the
ball of their foot touching the floor, can turn the handlebars
without hitting their knees, operate the gear and brake levers with
ease, there is nothing wrong with buying a bike from a bigger or
smaller age category.
12" Wheel - ages 2½ to 4
14" Wheel - ages 3 to 5
16" Wheel - ages 5 to 7
20" Wheel - ages 7 to 9
24" Wheel - ages 9 to 11
26"+ Wheel - ages 11+ (adult cycles)
When buying 12" & 14" wheel 'first bikes' there are many toys
bikes, sometimes cartoon and character branded bikes, which may not
feature high quality parts. They often feature plastic bushes
instead of steel bearings in the hubs and main cog assembly. Whilst
sometimes this works well and spare back up parts are also
provided, plastic bushes commonly wear out very quickly. For a
quality ride look for bikes that use ball bearings in the hubs and
main cog assembly.
Once your little angel has learnt to ride without stabilisers
(often at about age 5) they can move up to a 16" wheel cycle which
are not normally fitted with stabilisers, but they can be added if
needed.
With 20" wheel bikes and above, you start to get different frame
sizes. This gives smaller, confident riders the advantage of
fitting on to a larger wheeled bike. Here it's tempting to buy
little Johnny or little Suzie a larger bike that they can grow
into...which they will, but in the meantime they will find it a
difficult bike to control which can be very dangerous, particularly
where roads are involved.