Whatcha got spike, eh, eh eh
Sore knees ? maybe you're mashing...pushing too hard against a high gear. Try to keep your cadence (amount of pedal rotations per minute) high, or spinning as its known (forgive me if you already know)
I used to get sore knees when i started pushing along a bit....take it easy for a few rides, let them rest and get stronger. You dont have to stop...just take it easy.