The 187 Pro kneepads,  Friday, 22 February 2008 These pads are burly. Falling on your knees doesn't suck if you have these on. The dual enclosure system ensures that the pads won't slip down your leg. The first system is velcro for the top and bottom straps. The second system covers the first and consists of a ladderlock belt construction for the bottom strap and a second velcro fastening for the top strap. You can make them as tight as you want.
There is padding inside so that you don't jar your knee if you fall hard. I haven't had any knee pain after falling directly onto my knees.
The cap of the kneepad is slidey, so you don't go down and stick. If you fall, you're definitely going to slide a little bit. You can even run a few steps, then fall onto your knees just to see how awesome these pads are.
I use these kneepads primarily for downhill skateboarding. A slight problem that I have is the bulkiness of the pad getting in the way of my tuck. It's easy to adapt around it, but sometimes the pad on my back knee digs into the ankle of my front leg, which can hurt. Also when taking toeside turns, the cap sometimes hits the ground because it sticks out an inch or so. These are the only peeves I've experienced, and they don't happen very often.
Sometimes in a downhill bail, you don't fall directly onto your knees. I recently experienced a fall between 30 and 35 mph, in a overdrifted toeside turn. I slid down the hill on the side of my left leg; consequently, the side of the kneepad on that leg almost got destroyed. The straps were partially frayed and the buckle of the ladderlock fastening system was considerably shaved. I've heard that attaching slide pucks with velcro to the sides (on the outside of each leg) of the pads will guard against this.
Overall, these pads are wonderful! Pretty much perfect if you're serious about protecting your knees.