Would it be incredibly stupid....

...to wear brand new shoes on my 18 miler tomorrow? I'm pretty sure I already know the answer, but I figured I'd get some opinions anyway.

Here's a quick recap: I'm a flat-footed, overpronator and have been LOVING my NB 857's for over a year and a half. Not the same pair of shoes, of course, but the same model. The model has since been discontinued.

Last week I went to my local running store and told them I wanted a lighter shoe, and ended up with one with less stability (I bought the 767's). I ran 4.5 miles in them one night before wearing them in the BAA Half last weekend and didn't feel any ill-effects.

Well, after giving it much thought, I decided that since I'm only about 5 weeks out from Philly (my first marathon), I don't want to chance 26.2 without all the stibility I'm used to. I like the shoes I got well enough to use after the marathon, but I just would rather play it safe for the big dance.

So last night I went to the local NB store and picked up a pair of the 858's, the direct replacement for the 857's.

I know conventional wisdom says to break in new shoes over several shorter runs, but since I didn't have any disasters last weekend after 13, whats another 5 miles, right?

Truth-be-told, I've got my ragged old 857's layed out with my running clothes for tomorrow, but I'm just checking to see if anyone has tried such a thing and how they fared.

Thanks for any input!!

One trick that I use in your situation is to take the broken in insoles out of the old shoes and put them in the new shoes.
I would start the run in the new shoes, with the option of changing back to the old ones mid run if need be.

Good luck!
hup

if they are the same shoe for the most part, i do not see why not. I have done it many times.

If my old shoes are past a certain point, I'll wear the new ones.

I wore new shoes for my first marathon because my joints were hurting running in the old ones. No problems.

Thanks for all the replies.

I did end up wearing the old ones, just to be cautious. Although I'm sure I could have worn them, knowing my luck I would have gotten hurt 5 weeks out.

I'm looking forward to trying out the new pair tomorrow night!