locking brakes, why?
From what I am told is that people generally want to do it because then they know they can go up to, and then beyond, maximum braking if they need it. It is more of a mental security thing, because I don't think many people would actually do that very often as a flat spot on tires is very annoying relative to noise/vibration and expensive to repair (replace tires). I think people do it to adjust their controller to be on the "edge of locked brakes". Of course all this kind of adjustment goes out the windows when adjusted on perfectly dry good surface and then it rains, or some gravel and so on, where then brakes would lock very easily. It is kind of like why do I have a vette, which I do drive like it was intended to be driven? Does it make sense that I smoke those tires, slide around a corner or two, get up to "freeway speed" in eyeblink speed? Because I can. My dad can't understand why I would smoke some perfectly good tires, why I need 400HP where 125 will do and so forth. I know braking it is perhaps more of a safety mind set and is one of the metrics people expect from their brakes as there is nothing more frightening then trying to stop and not being able to lock them up if you want to do so. I don't know about others, but if I can't lock up the tires on my vehicle I do a brake job, so I guess I would probably feel the same way with a trailer. As an engineer, that is just me as I always need to push the edge and something I would also expect from my brakes. I wouldn't operate in that range, would just like to khow I could if I wanted to do so.