Cycling Knickers

I saw that Performance is having an upcoming sale, so I was thinking about looking for some cycling tights and/or knickers for the fall. I am 5'11, with a pretty long inseam, and um, chubby legs. :rolleyes:
I've tried on a few pairs of knickers and noticed that they hit right below my knee (not sure if they should be more mid calf?) and feel sort of tight.
I'm thinking that they might irritate the back of my knee after riding for just a few minutes??
I'm a pretty recreational type rider, mostly 15 mile rides for fun, but I definitely use cycling shorts with a chamois on all of my rides.
Thoughts on knickers? Do they irritate you behind the knee when you ride? Any suggestions on some that are a bit looser in the bottom? Or just skip them and go with tights?

I have a pair of Shebeest knickers that I love. They hit me about mid-calf (they probably should hit below the knee but I have short legs). They don't irritate at all. I love them!
In fact, I probably need to order more since I'm having lots of issues with my legs burning on my lower thighs/knees this summer (sunscreen is doing nothing).

I can wear the knickers until it starts to get really cold, then I just put tights on over them for winter.

Be sure the knickers you buy have a long inseam. I too have a problem with the shorter knickers due to long legs.
The Terry bella knickers have a nice long length and great in every way for me.
I wear long wool socks or leg warmers if I need more warmth. Leg warmers are easy to take off if temps warm-up. Knickers can provide comfort in a wide range of temps if layered.
Living in the cold winter climate I find a need for tights, but overall wear my knickers year round.

Loves my knickers.
On rare occasions when the 'behind the knee' is bugging me, I just pull 'em up a bit. If they're too tight, I'd just cut 'em.

I'm 6' with, as the bike fitter told me, "gargantuan femurs".... That said, knickers can be problematic. I've never found an off-the-shelf knicker that does fit as you describe, just below the knee. Some do cut into the back of the knee, but others don't. It depends upon the fabric and the cut.

My best bet for shorts, knickers and tights has been boure (boure.com). While I have them make custom shorts for me (about 4" longer than their standard short), I have yet to pay up and do the same for knickers. They're knickers don't seem to cause me problems even though the knee articulation is about 2" above my knee. Other brands have chafed at the back of the knee. In the end, it all becomes trial and error I'm afraid.

I have Sheebeast knickers and love them. I am 5'9.25" and they are mid calf on me.