By: Justin Lucke
Buying a new bike comes with an often overwhelming number of decisions -- bike size and style, obviously, but also stem length, pedal type, saddle choice, not too mention the complexity of fitting the bicycle. Revolutions in Fitness offers the Help Me Buy a Bike (HMBAB) fit to cut through the noise and provide evidence based guidance on the bike buying process.
Given the complexity and expense of a new bike, the option of switching to a different length crank arm is often overlooked. Compared to other fit variables on the bike like stems, handlebars and saddles, cranks are a relatively expensive option to tack onto the expense of the new bike. But of all the variables that you can change, cranks surprisingly can have a profound impact on comfort, performance and fit. It is definitely worth considering the change to shorter cranks and the HMBAB process allows to provide the evidence to make the change confidently.
As for performance, we can point to research that there is not much relationship, if any, between crank length and power (Jim Martin podcast / article ) -- the body almost immediately adapts cadence to make up for the minimal loss in leverage. And while there is strong anecdotal evidence that shorter cranks fit better and feel better, determining if they make sense for you makes the most sense (see also this article by fitter Rick Schulz). As the saying goes, “If you’re not assessing you're guessing." In short (poor pun intended), when we do a Help me buy a bike service / video we can assess:
Crank length depends in part on a rider’s
Hip flexibility
Leg length
Bike fit needs (like aerodynamics, pain / dysfunction)
We then use our fit bike with adjustable sizing cranks to instantaneously assess what an optimal crank length is for a rider using tech feedback loops
Pelvic stability as measured w/ pressure map
Foot Power (blog) / stability as measured w/ pressure map
Lumbar / Pelvic posture
Change in knee and hip bending/flexion at the top of the pedal stroke
Depending on your needs and goals as a rider, Revolutions in Fitness works with you to come up with the best new bike solution. From bar position to frame size to crank length, we can work out ahead of time what works best so you can buy your new bike with confidence!
