Well for starters, you can always decide to do the metric instead of the full century. You can even make the decision after you start the ride.

I've been having problems with my right Achilles tendon lately, which was caused by some sandals I've been wearing a lot. It hurts when I wear the sandals and also sometimes while riding the bike. Stretching it seems to help, but not as much as wearing different sandals.

As for toes, I have to keep all my toenails very short to avoid painful toes on long rides. They look hysterical with nail polish, like someone drew lines on my toes with a Sharpie.

BTW, I would ice the Achilles tendon.