I have a small knee ache and just came up with a theory why it happens, so I want to hear what you think.

First to specify the pain. It's just a slight pain I feel in my right knee, at first it was above the knee cap, now it moved to the right, it occurs after longer rides (around 100+ km), more often if it's hilly terrain.

Also, generally, even now when I'm sitting at my desk, I feel a slight tension in my right knee, I feel the need to straighten my right leg.

Now, for my theory. I think I am using too low of a gear on flats, or, comparatively, too high of a gear when going uphill, so my legs are under too much stress when climbing hills, which wouldn't be the case if I trained them by pedaling in higher gears in flats.

To be more specific, when riding flat terrain, My favorite gearing is 32/14, if the ride is short (30-50km), I can maintain speeds of about 30km/h (about 18 mph), which I believe is at a cadence above 100. If I am doing longer rides, my speed on flats is maybe 25,26km/h (about 16mph), maybe 28km/h on a good day, which is I think something between 90 and 100 cadence wise.

Then, when I hit the hills, for instance there is this 5km climb which averages something between 5% in 7% in grade, and I will climb it 32/21 or 32/24 with cadence I would say about 80, maybe higher if I am in the mood, but it's a considerably tougher effort and I feel and tolerate a slight but not numbing leg burn all the way.

But then, there is another hill, near my house, much steeper, maxes out at about 14%, most of the time it's between 7% and 10%, and I usually try as hard as I can to ride it in 32/24, and I really don't know the cadence because I'mt out of my breath there. I try to do it because I like to maintain at least some speed when going uphill, switching to the granny chainring (22), I drop to a lousy speed, even though I try to raise my cadence, but it's hard for me to maintain a proper pedaling motion when my heart rate is so high.

(Of course I do switch to granny gears when I'm tired but that's my last resort, just short of walking)

So, my question is, would it be reasonable to start riding flats in a higher gear (while still keeping cadence above 90), in order to develop more muscle or muscular endurance or whatever, so my hill climbing wouldn't be so stressful for my legs, or would it just further aggravate my slight knee problem?

Also when riding for errands around my neighborhood, I always go up short hills in high gears, practising out of the saddle climbing etc.

I understand there is a third option of riding hills in granny gears, and maybe it's the soundest for my knee health, but I just don't like superslow climbing.

Btw, I'm 24 years old, 193cm height, weight about 83-4kg, if it's of any importance.

And for the sake of discussion, let's assume my saddle height and all of that is correct, which it is by all standards, and I don't ride clipless, just regular platform pedals.