Does the stiffness of cycling shoes really matter?


It has long been assumed that rigid cycling shoes without a clip offer increased performance and efficiency advantages over more flexible shoes. However, a new study from the Department of Mechanical Engineering at the University of Colorado suggests that this is not always the case.

In an analysis of the measurable benefits of cycling shoes and clipless pedals used by competitive and recreational road cyclists, researchers found no hard evidence that an ultra-stiff sole is a winning choice for sprinting.

How was the study conducted?

The runners tested the shoes on a short uphill slope.
Joseph Branston / Immediate Media

Sports scientists measured the mechanical powers, speeds and cadences of 19 healthy male cyclists during a series of 50m flat sprints.

The runners tested three shoes, all with identical uppers, which were attached to soles with very different degrees of stiffness – the most flexible shoe used injection molded soles, the second a carbon fiber / carbon fiber blend. glass and the stiffest shoe featured a carbon fiber sole.

All riders rode outdoors on a paved asphalt road with a steady uphill grade (4.9%) and used the same clipless pedals throughout the tests.

What were the conclusions of the study?

Comparison of the stiffness of cycling shoes

The study showed little or no difference in performance when comparing shoes of different stiffness.
Simon von Bromley / Immediate Media

No difference was detected between the three shoe soles.

The measurements of average and maximum power, average and maximum cadence, maximum sprint speed, acceleration and crank torque were almost identical.

“We found no difference in performance between the less stiff and stiffer road cycling shoe soles during short uphill sprints among recreational / competitive cyclists,” concluded lead researcher Rodger Kram.

According to their research, the stiffest cycling shoe soles, compared to both a moderately stiff and less stiff road cycling shoe offered by a “well-known manufacturer” showed no performance advantage in the market. :

  • 50m average and peak power of one second
  • Average and maximum speed change
  • Maximum speed
  • Maximum acceleration
  • Peak torque

The researchers also expressed surprise at the consistency of results during the short sprints.

Does this mean that soft shoes are as fast as rigid shoes?

Shimano SD5 sandals

Before you ditch your stiff cycling shoes in favor of stylish SPD sandals, consider these points.
Reuben Bakker-Dyos / Immediate media

Before you cancel your order for these stylish, rigid-soled Giros and go for your old-fashioned sneakers, remember that this is also just a trial run, among a small group of runners. trained focused on the “longitudinal stiffness of the sole” and its impact on a few seconds of sprinting at full speed.

Over longer periods of time, differences in sole stiffness may produce benefits. Some bicycle assembly specialists agree.

“Sprint performance isn’t normally the main reason for choosing a stiffer shoe, at least not from a bike fit perspective,” suggests Innes Ogilvy of Bramblers Cycling, an Edinburgh-based bicycle fitter. “And the results of this study probably won’t help people find the right shoe.”

“I think the reason for designing a stiff shoe or buying one should be to improve comfort,” Ogilvy adds. “In my experience, those who have intentionally gone for more flexible cycling shoes tend to have bad experiences with stiff shoes because they bought something that didn’t fit them, not because it was. rigid.”

Bont Zero + Semi-Custom Cycling Shoes

Bont argues that stiffness is important.
Simon von Bromley / Immediate Media

The latest study raised eyebrows among cycling shoe designers. “If their point were true, you could easily run with a pair of running shoes, which obviously isn’t the case at all,” insists Istvan Nemeth, CEO of Bont Cycling.

Kram’s own previous research supports this claim.

A study published in 2019 comparing the results of 12 riders testing rigid-soled shoes and clipless pedals with running shoes – which typically have near zero longitudinal stiffness – and platform pedals found that stiff shoes without clip produced much better performance stats and have been shown to positively improve cycling performance during high power uphill sprints.

Generally speaking, this suggests that while there is an advantage in choosing stiffer shoes, the performance returns become extremely low beyond a certain point.

The 2020 study wasn’t able to pinpoint where that critical point is, but, for most of us, it’s probably safe to assume that even entry-level shoes will provide all the stiffness that we need from a performance point of view.

What about fit and comfort?

From races to whole days, these stiff shoes will keep you going.

Fit is more important than stiffness.
Russell Burton / Immediate Media

However, stiff shoes can have benefits beyond performance for some riders.

Mainly, because clipless pedals are so small (compared to flat pedals), a stiffer shoe helps distribute pedaling forces over the entire foot. If your automatic shoes were as flexible as a running shoe, you would be pushing your pedaling force into a small area, which is likely to be both inefficient and very uncomfortable.

Nemeth and Ogilvy both point out that, aside from stiffness, the key to getting the right shoes is having a good bike fit. “Our primary focus is on anatomical fit, structural support, and stiffness in that order,” Nemeth adds.

“Turning the pedals is a cyclical movement, good sprinters understand the importance of both uphill and downhill … Besides the stiffness of the sole, to support the foot uphill, you also need proper structural support on the above the foot.

“Plus having structural arch support that prevents the foot from pronouncing and acting as a shock absorber, and having shoes that allow your foot to effectively extend to the inside shoes, greatly contribute to increase efficiency.

“Simply rigid shoes are not enough and having rigid shoes without the other two parts being properly made will cause problems and discomfort. “

So, does shoe stiffness really matter?

In summary, compared to riding with flexible running shoes with flat pedals, a rigid clipless shoe will provide a tangible performance advantage.

However, the majority of automatic shoes on the market are likely to be stiff enough for most riders (although it is not known exactly how much “enough” is).

The most important thing is that you get a shoe suitable for the cycling discipline you have chosen, which also fits and supports your feet well.


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