Knee rolls internal during pedal stroke

Couple questions first:

What type of pedals are you using, SpeedPlays?
Does this cause pain?
How long have you been riding?

Because this happens after you have started your ride, I am guessing this isn't as much of an anatomical problem. When joints are problematic, its usually not the joint shows problems that is the cause, its usually the upper or lower join that has the origination of the problem.

I would look up Grey Cook and his work on body movement and how to go about assessing and correcting it. It sounds to me as this is a lateral strength issue in your legs, without seeing anything I really can't guarantee, this, and it's a guess based on what you have mentioned and I what I have seen personally with cyclists and runners in the field. But I would look into doing some corrective work on your legs, see below


****If NO pain is present, and this doesn't negatively effect your performance (lower watts) then I would say you are fine. People have this idea that if things don't look right they need to be fixed, but why? If nothing is broken, limiting your performance, or causing pain why fix it?***

Early this year I had knee pain when running over 1.5 miles, it turned out to be weak hip abductor muscles, in relation to the other leg muscles, causing my knee to collapse in slightly. The physio tested it by when I went to see him, make sure I went for a run before hand, to be fatigued. Then I did single leg squats and he noticed it was falling inwards. I strengthened it and the pain went. He advised against the exercise 'clams', as he had seen new research about rotor cuff problems or something like that.

It may be different for you as it's on the bike, but it can't help to check?

It usually doesn't involve pain. Sometimes it will get a bit sore after a particularly long ride (on the lower external side of the knee), but usually it's not an issue. As for the set up, I'm in SPDs. I did wonder about the potential adductor/abductor issue (I can never remember which is which), since it seems like that would be involved.

Adductor is on the inside of the leg (medial) muscles such as psoas, piriformis, TFL, etc. abductor is on the outside (lateral) muscles such as glute med/max, bicep femoris, rectus femurs, etc. and yes I would believe this is where your issue/problem arises from what I have to work with here. Ideally in a perfect world you want your legs to be like train tracks, go in a straight line forward, and you right now don't quite have that.

Check out what I posted earlier, lots of assessments, corrective exercises you can use to strengthen this issue. The FMS is a great tool to and work off this.

BUT If no pain or any decrease in performance happens I really wouldn't worry about it.