some questions and topics arising from my article on outsole widths and their impact on shoe speed have come up in the facebook comments appending to that article, as well as on the FB comments on my review today of the Bondi 5. easier to talk about this here, with images.
here's camilla pedersen. looks like a pretty normal footfall. the width of the outsole is probably not going to affect her as much.
likewise sebastian kienle. good footfall. not an issue.
i believe this is corrine abraham. she's going to touch down at an angle. we'll get to this.
likewise caroline steffen.
in my opinion, based just on my own running, my own sense of it, when you come down at an angle, as in the bottom 2 pics above, a wider outsole (esp at the heel) means that when you touch down the force of the ground levers your foot down, flat, abruptly, and more quickly than you want. if you toe off toward the inside of the shoe, which i do, same thing. the extra outsole on the medial side of the sole of the shoe impedes my ability to push off with my own mechanics.
two problems here. one is that levering. i'm funneled into a mechanical paradigm foreign to how i run. second, the shoe contacts the ground before i want it to, and it leaves the ground after i want it to, i.e., it spends more time on the ground (a no no, if you want to go fast).
ergo, my thesis is that for some runners - overpronaters in particular - suffer from shoes with wider footprints, possibly in injuries, probably in speed, and that this metric - outsole width - is probably more important than shoe weight in determining a shoe's speed. but, narrower shoes are less stable in certain conditions (offroad).
i think this describes, in part, why racing flats are so narrow, and why they've always tended to be flatter, heel to sole, than trainers (because that levering also occurs with shoes that have taller heels (more drop).
Dan Empfield
aka Slowman
here's camilla pedersen. looks like a pretty normal footfall. the width of the outsole is probably not going to affect her as much.
likewise sebastian kienle. good footfall. not an issue.
i believe this is corrine abraham. she's going to touch down at an angle. we'll get to this.
likewise caroline steffen.
in my opinion, based just on my own running, my own sense of it, when you come down at an angle, as in the bottom 2 pics above, a wider outsole (esp at the heel) means that when you touch down the force of the ground levers your foot down, flat, abruptly, and more quickly than you want. if you toe off toward the inside of the shoe, which i do, same thing. the extra outsole on the medial side of the sole of the shoe impedes my ability to push off with my own mechanics.
two problems here. one is that levering. i'm funneled into a mechanical paradigm foreign to how i run. second, the shoe contacts the ground before i want it to, and it leaves the ground after i want it to, i.e., it spends more time on the ground (a no no, if you want to go fast).
ergo, my thesis is that for some runners - overpronaters in particular - suffer from shoes with wider footprints, possibly in injuries, probably in speed, and that this metric - outsole width - is probably more important than shoe weight in determining a shoe's speed. but, narrower shoes are less stable in certain conditions (offroad).
i think this describes, in part, why racing flats are so narrow, and why they've always tended to be flatter, heel to sole, than trainers (because that levering also occurs with shoes that have taller heels (more drop).
Dan Empfield
aka Slowman