Pain at back of leg behind knee

[GmanUK65]

I am no expert - so just providing food for thought.

Increased muscular pain when cycling at a high cadence may suggest overstretching of the muscle (i.e. the muscle is too tight). Reasons I can think for this happening - you don't stretch enough, you drop your hip whilst cycling (i.e. one hip shuffles forwards a bit so you are not sitting square on the saddle), or you have an imbalance, possibly in leg length (history of broken limbs?.

Whilst pursuing professional assistance I would also consider:
1 - making sure you sit square on the saddle
2 - stretch stretch stretch, especially those hamstring. Touching your toes should be easy.
3 - photograph your legs whilst standing naturally and wearing cycling shorts and compare height of hip bones, knees and check for anything offset.
4 - get your saddle position sorted, consider a bike fit.

You've just made me realize that when I raised my saddle last week I noticed when the pedals were at their lowest point, my left leg (the leg in question) was less bent than my right, so maybe my saddle is too high. So, getting my saddle sorted and seeing the doc should hopefully sort my problem out. Another thing Ive thought of while writing this is that I have osteoarthritis in my left knee and I have read that the front of the knee will ache if the saddle is too low and this area of the knee never bothered me when I thought the saddle was too low unless I was in the wrong gear when climbing hills.

 

[montage]

You've just made me realize that when I raised my saddle last week I noticed when the pedals were at their lowest point, my left leg (the leg in question) was less bent than my right, so maybe my saddle is too high. So, getting my saddle sorted and seeing the doc should hopefully sort my problem out. Another thing Ive thought of while writing this is that I have osteoarthritis in my left knee and I have read that the front of the knee will ache if the saddle is too low and this area of the knee never bothered me when I thought the saddle was too low unless I was in the wrong gear when climbing hills.

When you see the doc, push for a physio referral. It is unlikely that the doc themselves will be of a huge amount of use unless you get extremely lucky and have a GP interested in sport

 

[ayceejay]

stretch stretch stretch, especially those hamstring. Touching your toes should be easy.
Although I agree with the need for stretching I don't think toe touching is any marker.
I think you get a better stretch of the hamstrings after a ride by holding the back of a chair or suitable sited rail and concentrating on bending from the pelvis, in your case it might be better to stretch with your knees slightly bent too.

 

[Crackle]

Back of the knee is, as Montage says, likely to be tight hamstrings. There are many hamstring stretches, find one that works for you, a couple I did made things worse, now I lie on my back and stretch the leg up with the other flat. You can also use a roller on hamstrings.

 

[S.Giles]

Your knee problems sound a lot like mine. I was in the habit of having the saddle a little higher than it was supposed to be. I lowered my saddle about 5mm at a time until the pain disappeared and that permanently solved the problem.