I've been pretty comfortable on my road bike all spring and summer. Just the past 2 Saturday's when I rode, I had a terrible pain on the outside right knee. Today it started after about 10 miles. I haven't changed anything on my bike lately. It did seem better if I kept my cadence really high, but I'm not used to riding that way. Also, on some of the hills, I end up in my lowest gear and spinning isn't always an option. I usually keep my cadence around 80.

I have clipless pedals and I double checked to make sure the cleat wasn't loose or anything.

Thoughts on why it just now started? How to fix? I am supposed to do a 60 mile charity ride next weekend, so I don't want to fiddle iwth things too much, but this pain could make it pretty unpleasant.