Original Vibram Five Fingers

Hello all,

Haven’t posted in ages and wanted to ask some of the experts here if they could shed any light on the following:

Early Vibram Five Finger (SKU V5151574, for example) soles I think had “micro slots” (for want of a better term) which were closed when the sole was at rest, and opened when the sole was flexed.

I cannot find much evidence of this other than the below image. I’ve highlighted the area that might show an “open” area.

Current product now seems to have a much more common sole design:

I’m wondering how the sole of the original, particularly the “micro slots” were formed? Think most soles are compression moulded however I don’t understand how the slots could be tooled, other than a secondary die-cut type process?

Laser siping

Siping is actually a very old technique. It is typically used in boat shoes. Check out a pair of Sperry’s. Same thing but it is done analog with a hot set of blades pressed into the fresh rubber. It is great for traction on smooth, wet surfaces because it creates so many teeth when it flexes. On dry land like concrete it tends to braid faster because of all the small contact patches, not to mention it adds cost. It is really cool though. I’m not sure how far it goes back. Decades.

Thanks all, very useful!