Shorter cranks? Really?!?

The debate is definitely on as to whether we are better off with shorter or longer cranks on our bikes.

For a number of years the general school of thought was that longer was better because like a longer lever, they should allow us to generate more power. However, for years we have overlooked that when we have longer crank arms on our bikes, our seats have to be lower to accommodate appropriate knee extension. The problem we have run into with this approach for some riders is that when the cranks are at 12 and 6 in the pedal stroke, the foot at the 12 position is much closer to the hip causing the hip to be in a more closed or acute position. For some riders this causes an impingement usually resulting in the knee kicking out and then coming down at an angle like we are chopping wood. This angle in the pedal stroke robs the rider of power while also not being ergonomically efficient with biomechanics of the pedal stroke.

A number of years ago, doctors who were performing total hip replacements and resurfacing on cyclist, recommended they have shorter crank arms installed on their bikes and be fit again to make sure the knee stays healthy. This also allowed for the hip to be more open when the crank position is at 12. For years that was the protocol and mindset. People with bad or replaced hips get shorter cranks. A couple decades into this protocol, someone noticed that the more athletic cyclist or those who continued to race post hip surgery; had other interesting gains. Once it was realized something else was happening to these cyclist once they had shorter crank arms and were re-fit to their bikes to accommodate the shorter cranks; the research began. This dive into all the cycling metrics of speed, power, aerodynamics and cadence revealed that there were some significant gains happening that could only be attributed to the shorter cranks. Riders seem to naturally gain 10-15 rpm in their cadence. This gain then seems to have a positive effect on average speed causing it to increase 1-2 mph on average. This also relates to a higher top end speed and eventually a higher watt output. Watt output is related to the number of times the cranks turn over in a minute in addition to how hard the rider is pushing the pedals. If you gain 10-15 revolutions per minute in your cadence, watt output has to increase. Another side bonus from shortening the cranks comes in the added aerodynamic efficiency. Once the rider's fit has been appropriately adjusted and they have fully acclimated to the new cranks and position, not only to they see gains in power output, average speed and top end speed, they see fairly significant gains in aerodynamics.

I encourage every cyclist who rides regularly to do the research and see for themselves what the world is saying about shorter cranks and the benefit of using them. Many of my clients have made the change and are loving it.

Please feel free to reach out with any questions about shorter cranks for your bike and how it could benefit you. Contact info is at the bottom of the page. Or click on the book now button and schedule a fit.