Seventy degrees? Are you trying to incite a riot? Until yesterday, it was at or below the freezing mark in my neck of the woods. The 12 inches of snow we got last week is starting to melt, but the slop is almost as bad as the snow. It's a mess out there. Needless to say, I'm jealous that you're able to ride at all, let alone in 70-degree weather. I haven't been able to ride since December 28th.
But to your question, I second the short sleaves and shorts. I might bring some arm warmers with me, but I don't bother to cover my knees unless it's 65 degrees or below. I might also wear a wicking base layer of some kind just for an added measure of dryness.
Kate
Live with intention. Walk to the edge. Listen hard. Practice wellness. Play with abandon. Laugh. Choose with no regret. Continue to learn. Appreciate your friends. Do what you love. Live as if this is all there is.
--Mary Anne Radmacher