Not a good combo. I'm sure most of you guys know this but I thought I would share. I am still new to all this but when I bought my first wheel/tire combo for my local clay track I decided on J Concepts Bar Codes (blue compound) and stock traxxas wheels (tra6872). I mounted the tires and foam and then glued after reading up and watching youtube vids. The tires seemed sort of soft on the out edge almost like they were flat. When I got the the track I asked the guys if they seemed to be mounted correctly and they agreed with me that they just didnt seem "right" After a few back and fourth emails with jconcepts I got this answer.
Here are some pics of my setup:What seems to be the issue is with the stock Slash wheel. The
original wheel tapers down from the large inside bead to the outer bead. All
of the latest wheels are straight out from bead to the outer bead, therefore
eliminating the air gap that the taper creates. Your tire, and insert are
fine, it is the air gap created by the wheel, that has you experiencing a
soft feel to the outer edge.
I knew I should have stuck with the black rolux wheels....