Achilles, Why?

Sunrise on Selby and FairviewOn my first run in these new size 13 Brooks PureGrit shoes, my left Achilles flared up again. Am I a barefoot-only runner now? I hope not. It can get really cold in Minnesota, and the Winter road slush is worse than snow alone. This does give me an idea for an equipment mash-up: Gortex zippered boot covered Huaraches!