So on Saturday I rode 50 miles. Never had a problem with distances before. The wind was blowing at 25 - 35mph, which sucked on big climbs.

Now, while going up a 14.4% climb, I noticed that my right knee started to hurt quite a bit. It initially felt like a cramp, but a cramp that I've never felt before.

The pain is on the right side, sort of behind the back of my leg (knee). It doesn't hurt when I bring my ankle towards my glute (arse), but when I extend my leg out (as though I was pushing down on the pedal) it hurts quite a bit. On Saturday it sucked to walk up or down any type of incline/decline. Today, it doesn't seem to hurt quite as bad.

Just curious if anyone else has experienced this?

Now, to give a bit of information. This is my first 50 miler of the year. I am thinking that this can be potentially too much too soon. The most I've rode this year is 30 miles. I haven't changed anything out on the bike or adjusted anything.

Suggestions?

I'm no expert, but I would suspect the toe in on your shoes/pedals may not be right.

Of Course, we all get it. It takes longer for ligiments to strengthen. Your muscles will get stronger and your knees hurt. Ride below you pain threshold as your knees (heal) stronger, thicker, and increased attachment area. Then you will feel good and go out and bust the hill. Oh! knees hurt again. We are talking aching knees. If you have Sharp pain that is injury and needs to be looked after.
The listless aching knees after a tough ride is your body grumbling about having to change. Eventually if you stay at it and listen to your body you become amazing, to yourself and others. I am not a Dr. but I ride free of pain and love the hills. Took me 6 years of mostly every other day riding. Sore legs, sore lungs, sore knees, all part of the journey. I feel I'm on a different level now and I like it.

Pain in the back of the knee is usually from over extending, from a seat that is too high or too far back.

Its likely that the extra stress of significantly increasing your miles, the wind, and the grade, exposed the problem.

So check and see if your seat height is too high, and try lowering it in small increments.

What gearing? How much vertical gain on the climb? How much standing, how much sitting?

Over 10-12% you are going to really stress your knees, particularly if you are out of gears and grinding, even more so if you're sitting while doing it.

Two things; positioning and riding style.

I find if I do long sessions out of the saddle I am putting undue pressure on my knees and then I spend half of my spin in pain.

Second, if you are riding high on the bike you may find there are issues with your knees. Too much hip roll while pedaling could be a factor.

Search "ITBS"

The jump from 30 to 50 miles is quite large this early in the season especially if you significantly increased the amount of climbing relative to the 30 mile rides. This aching is to be expected. Give it some rest or a recovery ride and you should be good in 24-48 hours.

Additionally you are not as limber early in the season as you are later if you have not been training in the off-season so it may be that your ligament was stretched a bit too much. Some people lower their saddle 1-3mm early in the season to compensate for this. I prefer to ease into the season by increasing my riding distance week on week by 15-20%.

I concur with the post that attributed the pain to a seatpost that is maybe a tad too high. You might mark the current position and lower it just 2 mm and see if that helps. The other thing is that you are obviously right-sided so you might also focus a little more on your left leg/pedal to even out the force.

Low gear and Spin: keep cadence up, no mashing.

Confirm seat not too high or too rearward - google it to find rough rules of thumb.

If still hurts, implement routine stretching after rides, look it up (ITB, quads, hams, etc); also start every other day strengthening in case you actually have patellofemoral (typically perceived as anterior, not posterior), including gluteus strengthening and short arc quad extension. This fixed my knee pain.

If those don't work, time to shell out some real dough and go to a good bike fitter and if that doesn't solve it then a PT. There's only so much that free advice on the internet can help you.

I've only had left knee pain...so I can't help...

I have a torn meniscus in my right knee. It only hurts when I DONT ride. Weird huh?

Not much to go on , and since it's (so far) an isolated thing, you might chalk it up to working so hard against the wind and climb.

So, for the moment, give it some rest, and try to take it easy on the next few rides and see how you make out. If it recurs or persists, then you can start to play detective.