Michael Hanslip Coaching

If you want to go faster, you have to pedal harder

Shoe lifespan

How long does a cycling shoe last? Obviously the answer is "it depends". But what does it depend on?
 
For road shoes it's subtle. With plastic soles, the sole declines in stiffness with use and age. This is demonstrable by comparing a brand-new pair with a well-used pair. Carbon soles will not do this - they should be as stiff at ride 1000 as at ride 1. If you walk in them much, however, they can get very scratched up. Most new carbon soles are incredibly shiny and well finished. That doesn't impact actual riding, however.
On my moderately wide feet, I tend to stretch out the (usually narrow) front part of the shoe with use to the point they feel loose. I try to have a new pair on hand at all times - just in case - and when I can discern a difference between the in-use pair and the new pair, it is time to retire the older shoes.
On more traditional shoes with velcro straps, the cling of the velcro was usually gone before the shoe was. With buckles and now dials, that doesn't apply.
I recently got 2 years out of a mid-range Northwave shoe that I never really liked that much before I called it a day and demoted my race shoes to commuting duty and promoted my in-the-box shoes to race duty. And yes that means I have no back-up shoes at the moment. Northwave has radically changed their shoes and the supply of new-old-stock obsolete models has dried up. I might have to try the new model or swap brands... Back to the retired shoes - that was 2 years of 30 km per day commuting duty, rain or shine, until I could really tell that the well loved shoes I had for racing were much more comfortable than the 2 year old ones with the faux carbon sole - the only carbon in it is the small circle where the cleat attaches that appears to be glued into a cavity in the plastic sole. That was a much shorter run than the full carbon soled shoes seem to last - almost everything was better about the high-end shoe compared to the mid-range shoe. They both had 2 dials to adjust the fit - these dials are identical on any Northwave that uses a dial. But the plastic sole, the fabric upper - even the reflective materials used (are shinier on the high end shoes than on these ones I recently retired).
 
For cleated MTB shoes, the end for me is usually when the tread is gone. Manufacturers tend to put so little rubber on the sole that what is there takes a high load and a beating every time you put them on. I've also seen a fair few pull the cleat out of the sole - that's a definitive end of lifespan issue. Like road shoes, it can be the shoe stretching too much, or the velcro losing its grip - but usually the shoe dies prior to anything like wearing out. MTB is hard on shoes!
 
For flat pedal shoes the end is usually, but not always, when the sole is so torn up by the pedal spikes that the insole is visible. These are generally lace-up shoes and new laces are easy. The shoe itself is usually the toughest of all cycling shoes too. Those grippy rubber soles erode on the pedal pins rather quickly. And that depends a bit on how rough the ride is - riding smooth singletrack doesn't push feet around on the pins like storming down rugged trails in a bike park off the chairlift does!
 
I guess the bottom line in shoe life is that changes are subtle and slow. Without the references to wear (poor fit, being able to see through the bottom of the shoe, etc) it would be easy to drag use out. Many riders do run their shoes longer than their feet might like.