Had a spill on the 24 guni today and got a gash just above my knee, which had 2 stitches put in it. I was wearing my 661s. They tend to slip down and leave the upper half of the knee exposed. Do other riders have this issue? Does KH leg armor do a better job, or are there other options?
I have Kh shin pads and the knee part stays up fine. Although I have never taken a big fall on the knees, just pedals going into my shins 
I’m wondering about sizing on the KH leg armor. I am 6’2’’, but I have skinny legs. The sizing chart shows I should get XL. Probably good for the length, but wondering if those would be too big around.
Useing knee pads with KH armor
I have the same problem. I find that using knee pads under my KH armor keeps them from moving around. Without the knee pads my KH armor moves all over the place.
I just got the 661 4x4s and while I haven’t used them for a long period yet, they do seem to stay up. I’m 6’ with long skinny arms and legs. The sizing chart said I was on the very low end of a size large, so I ordered the medium.
I use these:
http://www.backcountry.com/demon-snow-deluxe-shin-and-knee-guard
They have three velcro straps and they are designed such that I don’t see how they could slip down. They provide lots of coverage both above and below the knee, and have a rigid plastic knee-cap cover. Very comfortable and breatheable, and they are pretty cool looking too! 
I use soccer shin guards, and between the two my whole lower leg is covered. I am 6’3", 180lbs. I use the L/XL size knee guard.
ive had that happen a lot 
nothing to bad by any means though, but idk why but the pins on my pedals really like to dig into my knee there.
You can wear jeans while you ride to prevent it, haha i dont think you would want to ride like that were you live tho 
I use homemade shin guards I did each shin guard shin soccer with 2,
glue super powerful
Duct tape and placed inside a black sock and sew!
For knee protection I use tracker knee guard , the combination with my homemade shin with the tracker knee is blast awesome , one holds the other , so they never slip out of my leg!
the hole on the sock is because one day i tryed to drop about 1 meter and 50 cm and and the pedals come very very very ,fast to shock with my shin, it makes a high noise , but with normals pedals shocks , normally don´t do holes on the sock!
I’m about the same height as you and XL KH pads fit me. I used to wear 661s in size L, but Large KH pads were too short on me, so I swapped them for XL.
My shins aren’t enormous either, and the straps are a bit on the long side, especially the ankle one (some people must have really fat ankles!) They’re OK on me though, and if your legs are skinnier you could easily shorten them with a bit of stitching.
My legs are 19" from ankle bone lump (whatever that’s called… bottom of fibula?) to top of knee cap. If you’ve got long legs you may even want to go for the XXL, although the straps on those may well be very long. The bottom of the pad needs to be resting on your shoe to stop it sliding down and exposing your knee in a crash. [minor rant]Why is that tall people are assumed to be fat? It’s the same with t-shirts and cycling jerseys - medium ones fit me except for being too short, but large ones are really baggy [/minor rant]
Rob
Ran out of edit time…
I must add that I swapped to KH simply because 661 4x4s seem to be impossible to get hold of now, not because I had any problem with the 661s.
I don’t know if you talk about the old type of 4x4s that wrap around the leg rather that slide on over the foot. The old type I can’t find either, unfortunately. The newer type is currently pretty cheap here: http://www.blueskycycling.com/product2130_COMBOKIT_-661-4X4-Knee-Shin-Guards-&-2x4-Elbow-Guards-Combo-Kit.htm, in a combo with 2x4 underarm guards.
I hadn’t noticed there was a new kind. I think I’d get annoyed pretty quickly if I had to take my shoes off to get the pads on and off though.
Rob