How long is your back?

A large number of the people who come to me do so because they can’t get comfortable on their bikes.  Often they’ve experimented extensively and are as well versed in the ‘rules’ of bike fitting as I am.  They know the rules of saddle height and they know the ‘plumb line’ rule – but they just can’t get comfortable.

They’ve tried with the saddle forward and they’ve tried with the saddle backward.  They’ve tilted it up and they’ve tilted it down.  They’ve done the same with the handlebars and they’ve tried changing the stem.

If you find yourself in this position it’s quite possibly because, when it comes to your proportions, you are not average.  

Mass produced bikes are designed for averagely proportioned people and, as they are typically sold, they have very little scope for adjustment.  OK, they come in different sizes and the saddle can go up and down quite a long way,  so they cater well for a huge range of leg length, but they’re still only right for people with those average, or close to average proportions.  

But who the hell is average?  Take look around.  People (even professional cyclists) come in all sorts of shapes and sizes.  Some people have relatively long legs, some have relatively short legs, some have relatively long arms, some have relatively short arms, some have relatively long backs, some have relatively short backs, some have relatively long necks and some have relatively short necks.  And legs and arms are not always the same proportions either:  some people have long forearms and short upper arms, some people have long thighs and short short shins.  And vice versa.  And that’s before you factor in varying amounts of muscle, fat and flexibility.

So though you might not be averagely proportioned, nor is anybody else.  Despite what bike manufacturers would have us believe.  

These days the vast majority of bikes are factory produced and the options for truly custom frame geometry are very limited.  Fortunately off-the-peg frame geometries are not completely standard across manufacturers.  Specialized’s Mr. and Mrs. average, for instance, seem to be proportioned slightly differently from Trek’s: Cervelo’s are different again and so are Canyon’s.  And they also appear to think that you might somehow change your proportions for different types of riding so different models within their range often have different geometries.   

If, for example, you have relatively long legs, a relatively short back and relatively short arms, you’re likely to need a relatively short top tube and a relatively long head tube.  And you’ll want that combination for all of your cycling, not just for sportives!  If you have a long back and long arms, and relatively short legs, you’ll probably need a long top tube and a short head tube.  And you’ll want that for all of your cycling, not just criterium racing.

Unfortunately, however, bike manufacturers tend to create their different geometries simply by changing the stack (length of head tube) and reach (length of top tube).  They tend to stick to the same frame angles (74 & 75 degrees for small sizes, 73 & 74 for large sizes).  If you have relatively long femurs, or a relatively long back, this can make getting comfortable quite tricky.  You not only have to choose your frame particularly carefully, but also your components.

My little stock of components comprises mostly ‘geometry busters’ – items which allow average bikes to be adjusted to fit non-average people.  

A little more about the picture at the top.


The picture, here in its full glory, features four of Britain’s finest cyclists, all very differently proportioned.

Lizzie Diegnan, fourth in line, has a long, long back,

Nicki Brammier is tall with long legs

Sharon Laws was quite short with with long legs

Emma Pooley, out in front, has very short legs.  And indeed short everything relative to 700c wheels.

The event was the 2012 National Road Champs and was won by Sharon, who tragically died of cancer five and a half years later at the age of just 43.


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