I rode with a Bledsoe brace for a couple months after blowing my knee really bad. For those that don't know the bledsoe brace it is a dual hinge with padded straps that wrap the calfe and thigh. The hinge had two bars that connected to the hinge and ran up and down the leg. It probably was not the smartest thing to ride with this because the bars could have easily punctured my leg in an accident, but when you want to ride you want to ride. The bigest thing I noticed was when squeezing the bike with the leg you really could not feel where your leg was on the bike. I believe thats why they have the single and dual hinge models. I don't know if it was just fear of crashing or what , but I didi not feel comfortable riding fast with the brace. I guess I'm the type of rider that wants to feel the bike. I've since been able to rehab the knee enough to ride without the brace again. It did take a while though, the 40 yr old body heals slower.
That's my experiance with knee braces.