Here is some info I found when looking up TPU discoloration:
Flexible polyester-based TPUs can be vulnerable to damage from fungi and bacteria. The enzymes present in microorganisms can split ester bonds causing the TPU to discolor and crack – thereby affecting load-bearing capabilities...
What are people's thoughts on the Adizero prime boost? They are on sale for $140, looking at them for a workout shoe because I don't like wearing ultra boost to the gym.
Macy's retocked the CB 2.0 today, they are pretty much gone now though. 9.5 and 13 all that's left.
http://www1.macys.com/shop/product/adidas-mens-ultra-boost-running-sneakers-from-finish-line?ID=2882895&CategoryID=63266#fn=sp%3D1%26spc%3D5%26ruleId%3D84%26slotId%3D5%26kws%3Dultra%20boost