In reply to hdog76:
Matt,
I have had Achilles problems, once after a 100k sportive and more recently on day 2 of JOGLE. The first time was bad - I couldn't even put weight on that leg. Fortunately on JOGLE it was much less severe.
I have put it down to the specific shoes I was wearing. Both Achilles probs occurred while wearing my Bontrager shoes. I have had no problems whatsoever when wearing my Shimano shoes (on other 100k+ rides). In fact on JOGLE, after the problem arose and I swapped shoes, I was able to continue without it getting worse. Consequently the Bonts are condemned to short trips only now.
I don't think it is down specifically to the MAKE of shoes, but rather how the whole pedal/cleat/shoe/foot combo works. FWIW the sole of the Bontrager shoe is markedly more flexible than that of the Shimano..
Ice and lots of stretching helps recovery.
N