Broken Sole Dress Shoes – Updated 7 month review

I would like to start off by saying that I really like Dockers shoes. These are some of the most comfortable shoes I have owned.  This is why I am unhappy that they fell apart.  I like them so much that when the first pair fell apart after about 3 months I returned them for another pair of the same kind.  This pair lasted longer than the first pair but started to fail after 3 months and now 7 months after I bought them they are completely ruined.  As you can see in the pictures, both soles are cracked right through.

             

               

I tried to give them the benefit of the doubt, but it is clear to me now that there is a flaw in the design of the sole.  I say this because my first pair failed in the exact same spot. Also, a friend of mine bought a pair about the same time I bought my first pair and his failed in the exact same way in about the same amount of time. In fact, we returned the shoes on the same day, I got my second pair and he got a different brand. Now mine have failed again and his are going strong.

Here is what I believe is happening.  As I walk I am stepping down heel first and that is causing the heel section of the sole to rotate forward causing the sole to flex (strain).  The way that the section of the sole just in front of the heel connects to the heel section causes what is known as stress risers or stress concentrators. At these two points, the stress is higher than the material can hold and over time a tear or crack begins to form.  This type of crack will propagate (grow) perpendicular to the stress direction, which is exactly what we are seeing in the failure.

I feel that I need to take a minute and give a visual on stress concentrators.  I will use rubber bands to demo the idea of stress concentration.  For these demos the rubber bands will represent stress lines in a structure.  The closer they are to each other the higher the stress. Also, for these examples we will assume that the member is in tension. This means that the connecting points of the rubber bands are being pulled away from each other.

In the first picture the bands are straight and are evenly loaded.  They maintain the same distance apart.  There are no stress concentrations.

In the second picture the stress has to make a 90° corner.  As you can see the corner has a nice smooth transition and a large radius.  Any time stress changes direction you will see a concentration.  In this case we are controlling the location and magnitude of the stress by the size and shape of the radius.

In the third picture, once again, the stress makes a 90° corner.  In this example the corner comes to a sharp edge with no radius. Notice that the stress concentration is located directly on the point of the corner.  Unlike the second picture where the magnitude of stress was controlled by the radius, the sharp corner becomes a stress magnifier.  This concentration of stress over time will weaken the material at that point and will start a fatigue crack.  This crack will propagate (get bigger) on each following cycle (steps) until the rest of the material is too weak to hold the load and then BAM, Catastrophic Failure.

Here are some things that could reduce the stress at the failure points.

• Stiffen the sole material to reduce the flex at these points.
• Radius the sides that connect to the heel as shown in the picture below.

In conclusion:

Sometimes Style trumps structural design.  It is my opinion that in this case it was a mistake. I will continue to buy Dockers Dress Shoes, just not this style.  I will also take better care to inspect the soles to make sure they don’t have this issue.

Follow up:

I thought I was done with this write up but I just returned the shoes and I had quite the experience. I totally expected them to say, “Sorry for the inconvenience, we are happy to make it right.”

But instead the lady at the Customer Service counter said, “We will exchange them but you are really pushing it.”  I left the store completely perplexed. I was grateful that she exchanged the shoes but confused on what I should expect as a consumer when it comes to the quality and life expectancy of shoes.

This has forced me to go back and calculate how many hours these shoes have been used.

These shoes were my work and church shoes.  Here is how the math looks.

I work in an office and at my desk most of the day.  I figure that on an average day at work I am either standing of walking for 3 hours.  I worked 125 days wearing these shoes. This equals 375 hours.  I also wore them for 31 Sundays.  Again, I figure that I am standing or walking in these shoes for 40 minutes per Sunday, which rounds up to a total of 20.5 hours. All of this adds up to a grand total of 395.5 hours of walking or standing time. This is my best guess, but if I had to give a range I would say no less than 350 and no more than 450.  So let’s go with 450 hours for our comparisons.

Let’s say I was a Sales associate at a retail store or another job that required me to stand most of the day and had to wear the same shoes.  At 8 hours a day and 5 days a week my shoes would have been in the same shape in 56.25 work days.  This equals 11.25 weeks or 2.8 months.  Would anyone think that it would be reasonable to have to buy a $75 pair of shoes every 3 months? Keep in mind that you are replacing them because that broke not because they wore out.

I would really like to hear from everyone on this subject.  It is my opinion that they should go out of style before the wear out, and I should wear a hole in the sole before it breaks. I want to know how far off I am. I would like to know how long you think a pair of shoes should last.

Thanks for your comments.

By the way, check out the shoes I got as a replacement.

 

 

 

 

 

 

 

 

Docker Dress Shoes – 7 Month Follow up

Wow it has already been 7 months since I replaced these shoes. I won’t make this long but just wanted to show you how well these shoes are holding up.  As a reminder; I wear these shoes 5 to 6 days a week, just as I did with the pair that fell apart.

Look how well they are holding up, no stress at the heel and just a little wear on the tread from scuffing my feet when I walk. This is the quality I expected when I bought the first pair, too bad it took until the 3^rd pair.