Training & Nutrition - Strange knee problem

I have never experienced any problems while on the bike whether mashing or spinning. Not even a twinge. Lately, I've noticed that after riding, just walking, for the next 15 to 20 minutes is a problem. No steady pain but sometimes it's as if my knees just start to buckle and I get a twinge of shooting pain. Soon, it just goes away.

Basics...I'm not riding huge distances, just 15 to 30 miles or so. My speed is from 13 to 15 average with occasional peaks at 20 mph or so. This occurs whether I'm riding my road or mountain bike. I'm very confident that both bikes properly fit me. I'm in my mid 50's and just back to biking for a year or so and also a shrinking clydesdale. I'm not in great shape but I'm not totally out of shape.

Any thoughts

Is the pain directly under your kneecap?

Have you increased your mileage lately? Sounds like arthritis perhaps. Some strength-building in the gym should help that wobbly loose feeling by building up the ligaments and tendons in your knee.

are you using clipless pedals?
Is it one knee or bilateral?

Have you increased your mileage lately? Sounds like arthritis perhaps. Some strength-building in the gym should help that wobbly loose feeling by building up the ligaments and tendons in your knee.

What type of weight training is good for helping to rebuild tendons? A general weight lifting plan?

Yes I'm clipless but have been for a while. The pain is not directly under the patela but about an inch or so to the outside. It is occuring with both knees.

As I said in the OP...it seems strange to me that I have no discomfort in either knee on the bike, even up hills, just when I've stopped.

what pedal system are you using?
is it floating?

What type of weight training is good for helping to rebuild tendons? A general weight lifting plan?Well, pretty much all of the leg-exercises will build up knee-strength. Leg-press, leg-curls, calves, squats, etc. There's some good recommendations in Armstrong/Carmichael's book. :)