A while back I wrote a post about shoe soles, listing up the most important types and ranting a bit about ones I consider to be confusingly misnamed. One sole I decided not to include in that post was the ripple sole. Why? In my ignorance I considered it a bit of a novelty sole. In my defense it’s not one of the main types and I usually see it only on more specialist offerings from companies such as Yuketen and Fracap.
I was wrong to dismiss the ripple sole as a mere novelty sole though. As soles go it’s actually one of the more noteworthy. Why? It has a genuinely kickass story behind it. Indeed it does.
An inventor with the evocative name Nathan Hack patented the ripple soles back in 1955. Being a proper engineer, Mr Hack described his new soles as: “A resilient shoe sole formed with a series of spaced parallel resilient projections extending transversely of said shoe sole and at right angles to the length thereof, said projections being inclined rearwardly, whereby weight thereon causes a straight forward movement of the sole as said projections yield under weight.” (This is a description I found in the documents in a later court case upholding his patent).
The big idea behind them though was to reduce the amount of leg injuries experienced by Paratroopers when landing.So the result of having the ribs, or ripples, along the sole was to both increase traction and to providing better damping. And on top of that he created some very distinctive and functional soles indeed.
These days they are mainly used on Italian mountaineering boots and American heritage-inspired footwear. The fact that they are so distinctive means opinion is divided as to the look of them, some adore the cheeky style, while more conservative eyes find them a little frisky.
What is the actual functionality like though? I’ve been unable to contact any paratroopers with actual experience of them, although Google did produce results indicating that they can put a bit more spring in your step. My concerns in this respect would be using them in snow, where the traction in a strictly forwards direction should be about as optimal as you can imagine, but if there are sideways forces at play, such as when traversing a hill, those ripples could see you sliding sideways with nothing to reduce friction. Perhaps not such a common occurence in urban areas, but surely a potential issue when doing a spot of mountaineering?
As goes for most soles today, it is Vibram that produce the ripple soles, although you’ll find them listed in the “Dress & Casual” section under Lifestyle soles. This is on the other side of the screen from the hardcore mountaineering soles. So while the story of Mr Hack and his paratrooper innovations gives a nice historical backstory, we can safely assume that the state of the sole art has seen further innovation in the 60 years since.