Two shoe wear questions

Most of the shoes I have bought(Brooks, Adidas, NB)have a 2 layer sole, with the bottom part being black. How long do many of you run after the outside lateral heel bottom layer is gone, if at all?


For something like the Saucony Kinvara, which has a single layer, how do you know when they are worn out? --when the ridges are gone?

I know many of you use mileage, but I'm not Type A enough to record trail/road/treadmill/wet-rainy miles on every shoe, each of which has a different effect on the midsole.

Thanks.

Once I wear down the "black" on a two layer sole. I will wear the shoes maybe another week or two and carefully watch to make sure that the sole is still flat an not decidedly misshapen i.e. I tend to wear down the back outside of the heel and once there is an "angle" the shoe is done. The funny thing is for me that the lighter the shoe, the longer they last?

I know when my shoes are worn out when my knee starts hurting.

I don't let my shoes get to that point. I normally replace them (retire them) before the sole wears out.

Julie wrote:I know when my shoes are worn out when my knee starts hurting.

Or my shins - I've never worn through the black, even when I took my very first pairs of shoes way past when they should have been retired.