An admitted shoe geek waxes philosophical about running, triathlon, and life in general.
Comments welcome!

Sunday, January 16, 2011

If I were a shoe designer... Part 3

Last shape, insoles and footbeds:

I like insoles in my shoes. I can't say for sure why that is, but it's just something that's worked for me throughout all my years of running. Even with the "less shoe" emphasis, I find that the insole makes a big difference "for me". And since I'm being the shoe designer here... Footbeds and insoles I guess I see as almost the same thing. The only difference might be a "footbed" could be interpreted as contour on the top surface of the midsole, which I don't think is necessary, as long as the insole is there. I don't like sharp edges on the insole. The Kinvara insole (and most of the shoes I've worn) works quite well. I see that Altra is planning to ship two insoles with their shoes. Good move on their part. The Merrells have an insole similar to the Nike Waffle Racer (which I've used), and only time will tell if that's good or not. As long as the insole is large enough that the toes don't lap over the edge, it's good.

The last shape, though, is one of those make-or-break items for most people. This is what mostly determines if a shoe will "fit" or not. It's the shape over which the shoe is made. One of the things I've been having difficulty with over the last few years is the width at the forefoot, and I hear that it's something that all the new lines are addressing. The pointed toe shoe isn't it. The big toe should have enough room to line up directly with the first metatarsal, and not be pushed into the other toes. This is what causes bunions. Even my Kinvaras that are a good half-size larger that ANY shoes I've ever worn don't fully let my big toe point straight -- I can feel the shoe upper on the edge. Also, the shape of the shoe being curved inward at the little toe is an issue for me. Years of wearing shoes that pushed my toes together are OVER! I've realized that this has been happening since I started running back in high school -- my little toes have been pushed inward, and especially on my left foot, the toe has a sharp callus from being pushed under the 4th toe. Even recently, with my decidedly average width feet, in order to get enough toe room in some "formal" shoes I bought, I had to get EEE width. Fortunately, the heel wasn't proportionately wide, so they actually fit (neglecting the heel height, which there was no way to get around).

Anyway... Width in the forefoot, not just the toes.

And one thing that I'm seeing STILL is a cutaway under the rear head of the 5th metatarsal. Why? In a midfoot landing, the entire fifth metatarsal is load bearing. When the midsole material is cut away there, that puts an edge under that load bearing bone. BAD! Merrell did this, but I think Altra kept it there (especially in the Adam) and maybe New Balance (the Minimus Trail looks to have this dialed).

One issue I didn't mention last time in the midsole section: Little to no toe spring. I'm finding that any upward curve of my toes works against me. That's not to say that the midsole/sole can't roll upward away from the ground at rest. I like how the Kinvara (and the NB Minimus Road) do this -- the actual foot bed is flat, while the toe spring (what little there is) happens via the midsole.

Next time: Uppers.

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