Petite Test

Chris Juden examines bikes for the vertically challenged - with the help of fourteen small women!

This article was written by Chris Juden in 1994. Although some of the equipment has changed (bikes typically have more gears, for example) the needs of women cyclists haven't, nor has the fact that most manufacturers don't provide bicycles to meet these needs. The article concentrates on touring bikes but will be equally useful for a woman looking for a road (racing) bike. It won't be as helpful for a woman looking for a MTB, although many issues such as top tubes that aren't too long and appropriately sized cranks are still relevant.

This page introduces the problem, and there are quite a few accompanying pages.

Women in general, and smaller women in particular, have a lot of problems finding a comfortable bike. And after a week with fourteen of them in some of the hardest country England can offer, I assure you that this is not because they're an awkward and over-sensitive bunch who can't accept that cycling's a physical activity! Given a bike that really fitted them, with a good range of gears and brakes they could actually reach, some of these women amazed even themselves by the hills they could ride up and down.

If you look at the ranges of bicycles offered by mass producers and compare their vital statistics with the UK population, you find that they do a reasonable job of providing touring bikes for more than 90% of men. The typical 5 percentile British male (p5, which means that 5% measure less than this) stands 167cm (5'6) tall and fits a 51cm (20in) frame. The median (p50) woman is actually slightly shorter than this at 166cm (5'5), while Mrs 5% is only 155cm (5'1).

Big people tend to be more into sports and long-legged people are probably over represented in the cycling population - which may explain why manufacturers find it worthwhile providing the tallest 5% of men with frames up to 64cm. A few also go down to 49 or 48cm. According to their seat tubes, these smaller frames ought to suit the small to average woman, but when we look at their other dimensions we find that they have not been reduced in proportion. Very often the handlebars are just as far from the saddle, giving rise to the justified complaint of feeling too stretched out.

Vive la difference!

It is frequently stated that women have shorter torsos and longer legs than men of the same height. I've even repeated this supposition myself, but I'm afraid that the data do not support it. A general analysis of the adult population shows that big or small, man or woman, the average person's inside leg is some 47% of stature. Of course we are not all of average build, but men seem as likely as women to have relatively longer or shorter legs. Almost 50% of my height is leg - so I'm either a case in point or a freak! This ratio, by the way, varied from 45% to 49% for the petite test women.

A woman's pelvic structure is, however, quite different. And women do sit differently upon a bicycle: a little further back on the saddle (partly but not only so as to find a bit that's wide enough!) and apparently bend forward from a higher point on the spine. Both these factors introduce a need for the handlebars to be nearer and higher in relation to the saddle.

Flexibility of the spine varies greatly between individuals and reduces with age, a factor which plays havoc with nice formulae for designing bicycles on the basis of body dimensions. Young, athletic women seem better able to cope with the too-stretched-out riding position imposed upon them by a bike that is theoretically too long, but saddle problems can arise from an accompanying forward tilt of the pelvis. Less flexible individuals require higher and closer handlebars.

There are, of course, a few smaller male cyclists too. A couple of them contacted me about this test, mildly criticising its sexist character and suggesting some solutions to the size problem. But here's another difference: these chaps did not simply accept what is served up by the trade. Women, I'm afraid, often lack the technical interest and confidence to question the supposedly expert advice of shop staff and more experienced cycling companions - all of whom are usually men with a vested interest in providing something as near standard-issue as possible.

Alice in Bicycleland

Now we've accepted that there's a demand from smaller riders, let's enter the Alice in Wonderland world of shrinking bicycles. Pick up the bottle labelled Drink Me from the table and pour it over any average-sized, 57cm (22½in) tourer. It shrinks pretty well down to about 53cm (21in), reducing its length in proportion with height, at which point you notice that the magic fluid missed the cranks and the wheels.

Shrink the cranks

Alice (who has also taken a swig) doesn't like her feet hitting the front mudguard, and anyway: pedalling a 170mm circle makes the knees of her shrinking legs bend too much, so she manages to shake a few last drops onto the cranks.

Unfortunately it is much easier to fantasise about shorter cranks than walk into a shop and buy any. Aside from children's sizes, a choice in lengths is only offered by the most expensive models: and even then is intended to let a man of average build fine-tune his performance to a particular style of racing event rather than something more or less right for all the rest of us. Thus those who can afford it may obtain slight variations on 170mm, in 5mm or even 2.5mm steps, from 180 down to 160mm if you're lucky. (For the time being TA also have 150mm.) In this respect big blokes fare as badly as small women, but cranks that are too long do more damage to knees by making them bend too much. [For advice on where to get unusual length cranks, see Check your Cranks.]

It's obvious when you think about it: the crank is just one part of the thigh-shin-foot-crank linkage. Change the length of three of these links and you should change the other in proportion, but it's surprising how many minds cannot be opened to this obvious reality. And the recommendations of those who do accept that varying crank length is a good idea, fall well short of a truly proportional relationship, probably in an attempt to reconcile the reader to the limitations of what is available.

I have long recommended that cranks be about 20% of leg length. Coincidentally, I've recently discovered the same figure was found to be the optimum by a couple of Californian researchers using a lab-full of machinery (Gross & Bennett, 1976). Their conclusion that the standard length of crank is too long for 60% of men and almost 100% of women was not widely reported in the cycling press of the day. Could this be because to fit 90% of (British) adults we'd need cranks from 150 to 180mm long - a far wider range than that provided by most potential advertisers? Of course, the human body is quite adaptable and most people can tolerate some variation. Limits of 20% to 21% seem reasonable. People with dodgy knees are advised to keep to the lower figure, while bigger than average feet can help short legs accommodate longer than optimum cranks.

People who switch to shorter cranks may initially notice some loss of power, but they soon develop a more rapid and fluid cadence - previously inhibited by excessively long cranks. They can then develop the same or more power by spinning a lower gear faster [see Improve your spin], and should alter their gears accordingly.

Smaller wheels for smaller people

Proportional crank length only buys a bit of time for shrinking Alice and her bike (until about 52cm or 20½in) at which point that stubbornly 700C wheel not only catches up with the shrinking crank but also prevents the head tube getting any shorter. What now?

The obvious thing to do is also to shrink the wheels. By doing this we make the whole bike an exactly similar model of it's full-size original. We've already seen that small people have the same proportions - on average - as bigger ones, so why should bikes be any different? Of course they shouldn't really. All the problems of toes overlapping mudguards and head-tubes too short for the headset are solved: everything falls neatly into place if the wheel is smaller too.

Why don't smaller frames routinely have smaller wheels then? It's because only the smallest adult sizes need them and big manufacturers find it much simpler either to ignore inconveniently small potential customers, and/or to mangle the frame geometry of their smallest offered size so as to shoehorn the factory's standard wheel for that model range into it. This artificially restricts the market for smaller wheel sizes to children and a few specialised types of bicycle such as folders and hpvs. The result is that those who accept that smaller wheels are the solution and want to build bikes with them have little choice of tyres and rims and their customers are put off by poor spares availability.

Some framebuilders and one or two small manufacturers nevertheless adopt this, the engineering solution. Most of them make both wheels smaller, but the rear does not really need scaling down.

Leaving the rear big does not cause any rider fit or design problems and has a few advantages. Rear tyres wear much (3 or 4 times) faster, puncture and are damaged (likewise rear rims) more often than front ones; hence the parts you're going to need to replace most often are easy to replace and interchangeable with those used by your larger companions. Against this stands the need to carry two spare tubes - not that I would bother on a day-ride. I'd mend the rare front punctures or in an emergency a larger tube can always be concertina'd into a smaller tyre.

Low-profile racing bikes have made smaller front wheels more acceptable, and they are found on a few bikes in America, notably the Georgena Terry range specifically designed for women. Unfortunately these are not imported here. All of the those who responded with smaller wheels to the challenge of making a bike for our Petite Test used the same size front and rear. This means that you must keep a good stock of tyres at home, to deal with a more frequent need for hard-to-get replacements, but in the long term should result in a bigger market for alternatives to 700C; and I'm all in favour of that! For some information on the alternatives see the section What size small wheel?.

But I must have 700C!

The simplest thing for those who won't bite the small wheel bullet is to give up making the frame any shorter or lower and raise the pedals instead. Shrinking Alice doesn't like this at all. She can no longer stand over the frame, but has to hop off to the side, leaving one leg hooked jauntily over the top tube. Okay, so we can put in a sloping top-tube or even give her a step-through frame, but it's still t-o-o l-o-n-g. And if Alice wants to halt while seated by putting just one toe to the floor - an action which taller riders take for granted - she can't do so without lowering the saddle - which makes her pedal inefficiently with over-bent knees. Smaller bikes should have a lower bottom-bracket not a higher one.

The most obvious and dangerous problem with such long little frames is that our Alice is so stretched out she can hardly reach the bars and brakes. She feels less in control of the bike and so she is. She cannot do U-turns and creeps down hills; and all this leaning forwards causes acute saddle discomfort.

Shorter stems can help the length problem, but only a little, and nice-looking stems only come in long extensions. Women, as I have already observed, often like their handlebars higher, and a custom-built stem can often transform an ill-fitting mass-produced bike, by putting the handlebars precisely where you want them, at a fraction the cost of a custom frame.

Short-reach brake levers are available but seldom fitted to ready-made bikes. Braking is a subject in itself, for which see the section The brake lever problem.

Mangled angles

As frame size drops below 52cm the phrase 'variable geometry' can take on a whole new meaning. Above this level it implies small adjustments to the seat angle of a ½° or 1° plus or minus, so as to fit the frame to the rider's body. From here on down it tends to become a euphemism for wholesale alterations to the steering and riding position in order to make the body fit the machine!

Reducing the head angle is relatively harmless and helps in three ways. Shallower angles are accompanied by extra fork rake - allowing the frame to be made some 15mm shorter per degree - while the head-tube may be made slightly longer as it is swung further behind the front wheel. But anything below 71° is uncharted water to most framebuilders - who are understandably reluctant to tempt the vengeful gods of steering geometry!

Due to the fact that common varieties of seat post place the part of the saddle the rider sits on some way behind the line of the seat tube, there's good reason for this line being a little steeper for smaller riders. If 73° is right for the average-sized touring frame, then 74° should suit the petite: a change which (in a small frame) moves the bottom-bracket nearly 1cm further from the front wheel for a given top-tube length. But this just isn't enough to sort out the foot-in-wheel problem as Alice and her bike shrink through the 51cm frame-size barrier, so the designer gets hold of the seat tube and yanks it forwards by a good 2 or 3 degrees - sometimes even more!

A 77° seat angle brings the saddle about 3cm closer to the handlebars compared to 74°. This would be all very well on a small racing bike, since it brings the rider's weight further forward of the pedals in a manner which helps the rider press harder upon them. But our Alice does not want to pedal harder - after all she is supposed to be touring - and finds to her discomfort that relaxing her pedalling effort now requires a greater proportion of her weight to be supported by hands and arms.

[The angles for the test bikes are given in the Geometry section.]

Compromise, compromise

The skilled custom builder will employ all these measures - sloping top-tube; shallow head; steeper seat - in order to build a frame that will somehow arrange standard-sized components around a small-sized rider. For riders needing a touring frame under 50cm such a frame can only be regarded as a compromise. If the builder is skilled at interpreting the wishes of the rider that can be a reasonably happy compromise, and certainly better than an off-the-peg bike that is altogether too big.

If you can accept a smaller wheel this removes all the compromises. Sloping top-tubes and small variations in geometry still have a place in such designs: as a means to making the machine fit the rider rather than vice versa.

The accompanying reviews of bikes supplied for this test should give you an idea of what to expect from the builders concerned and the various design strategies they have adopted. The problem is that beginners won't want to spend custom-built prices on equipment, when they don't yet know if they'll enjoy cycling. Sadly, the little lady's first touring bike is most likely a ready-made model that doesn't fit: and upon which she is never a really comfortable or effective rider. This, in turn, ensures that she never enjoys cycling enough to want to spend the kind of money it takes to get a properly fitted custom job: catch 22! And many experienced riders don't have that kind of money either.

The ATB option

All the above assumes road bike sizing. Mountain or all-terrain bikes (ATBs) come in much smaller sizes, which attracts the smaller rider even if they have no intention of going off road. Nowadays the frame weights of the best models are competitive with a 531ST tourer and there's a limited selection of road-going tyres (with plenty of narrow rims to suit thanks to the mountainbiker's disregard for conventional tyre-fitting wisdom!). Fit these smaller tyres and the pedals should not be quite so far off the road (you might even be able to get a foot down in traffic) and there will be space for mudguards.

So far so good, but these apparently smaller frames are also proportioned for Mr average. You need to subtract 7 to 10cm (at least 3in) from the size of road bike you'd expect to ride when looking instead at ATBs. This is because all the other proportions of the frame are designed for someone who wants to crash land without squashing his dangly bits against the top tube, and hence rides with a foot or so of seat pillar showing beyond that apparently short seat tube. Try riding an ATB you can just stand over and the bars will be much too far from the saddle. The same applies to a lesser extent to 'hybrid' bikes - the frame size may be smaller but the whole bike isn't.

In September, Mountain Biking UK published their own petite test (did they get the idea from us I wonder) and concluded that the smallest available, 14 to 15in frame models would be OK for women over 157cm (5'2). This is 1 or 2in less than can ride a 49cm (19½in) tourer - but still leaves quite a lot in the lurch.

Other pages in the Petite Bike Test:

More bike articles