If you want to spark a debate among cyclists, bring up the subject of saddle height. With a number of saddle positioning strategies in circulation, all of which have their advocates, cyclists have reason to be confused.
There is one thing they’re not confused about, however: Saddle height is important. Too high or too low and knee pain can set in, especially among those who log serious mileage on their bikes. But that’s not the only downside of an ill-positioned saddle. Cycling power and efficiency are both reduced when saddle height isn’t adjusted properly.
For most casual cyclists, saddling up is as simple as hopping on your bike and taking it for a spin. If your hips rock side to side while turning the pedals, the saddle needs lowering. If your knees are in danger of hitting the handlebars, you raise it up a notch or two.
That kind of casual approach doesn’t sit well with everyone.
The staff at most cycling stores suggest sitting in your saddle and adjusting its height until you can keep your knee straight with the heel of your foot on the pedal while it is at the bottom of the pedal stroke (six o’clock position). Once that’s accomplished, you’re at or near the optimum saddle position, which is characterized by a slightly bent knee at the bottom of the stroke while the ball of the foot is positioned over the centre of the pedal.
Both of these low-tech approaches actually come close to getting it right. But for serious cyclists, close isn’t good enough. Seemingly small maladjustments in saddle height can make a long ride uncomfortable. It can also hit where it really hurts, in a cyclist’s performance. Hence the debate about the value of sophisticated measurement tools and complicated formulas in order to get it right.
One of the more popular formulas for saddle height is the Hamley and Thomas model, which recommends setting the saddle height at 109 per cent of inseam length in centimetres (measure from crotch to floor and multiply by 1.09). This measurement is then used to determine saddle height as measured from the centre of the pedal axle at the bottom of the stroke to the top of the saddle.
An alternative measure is the Holmes method, which suggests adjusting saddle height to accommodate a bent knee angle of 25 to 35 degrees while the pedal is positioned at the bottom of the stroke.
The Hamley and Thomas method is reputed to offer the best performance benefits in terms of ensuring optimum cycling economy (defined by the lowest amount of energy expended at a given resistance) and power, while the Holmes method is touted as being the easiest on the knees.
When measured against each other, both approaches result in different saddle height recommendations for the same individual — which is largely due to the fact that the Hamley and Thomas method doesn’t take into account the large individual variation in leg length. This disparity leaves cyclists with no other option than to choose between a technique that promises optimal performance and one that promises pain-free knees.
Armed with this knowledge, researchers from the universities of Northern Kentucky and North Alabama decided to put both methods to the test.
They evaluated cycling power and economy in 11 well-trained cyclists with the saddle positioned at three different heights — the 109 per cent inseam method, 25-degree knee flexion and 35-degree knee flexion. Power was evaluated during 30-second sprints and economy was tested by pedalling 15 minutes at a fixed resistance and cadence.
In all the tests (peak power, cycling economy and perceived exertion), the 25-degree knee angle either equalled or outperformed all other techniques designed to optimize saddle height. And while the differences between the tests were in some cases statistically small, when it comes to high-level cyclists who want all the power and cycling economy they can get, a little goes a long way.
What does all of this mean for cycling enthusiasts? Well, it finally ends the debate on which approach offers the best results. And it allows bike fitters, both professional and amateur, to perfect and administer one method of measurement.
That being said, gauging 25 degrees of knee flexion isn’t something you can do with your old high school geometry set. It takes a specialized tool called a goniometer and an experienced set of hands and eyes.
Most bike stores have a bike fitter on staff, so let them do the leg work while you share your insight into why you want the saddle adjusted to accommodate 25 degrees of flexion while the foot is positioned at the bottom of the stroke cycle.
As always, there are those who sit outside the norm and may perform or feel better using another technique. And there are those who are happy with the trial and error approach to saddle height. But if you’re a serious cyclist, this isn’t just more fodder for debate — it’s potentially the answer to an age-old question: How high should I put my saddle?