There are quite a few reasons why highway pegs are dangerous (and some of these go for forward controls too):
- your feet are far away from controls ie. the brake pedal
- weight distribution is wrong for for handling
- b/c your pegs are solid mounted if they ever touch ground they become a pole vault- stock pegs come with a hinge for a reason
-the rod you used isn't all that strong, if you ever come upon a situation where you have to stand up fast it's likely the rod will bend which could be the 1st step to a serious wipeout. This happened to me w/ highway pegs on a virago, they hang down from the steering neck. A chunk of wood came off a truck, I didn't have time to move my feet to the back pegs so I put my weight on the front pegs, they snapped right off on the highway.
-another thing to consider is how sharp they are, I know a lot of guys are rolling their eyes, but if you do crash do you want one of those things impaling you? Maybe a long shot, but when you're going down everything becomes a weapon.
Now that I'm done my sermon, I believe the cool thing about bikes especially older ones is that a rider can convert it into what he wants. If you want highway pegs, go ahead and put them on, I've had them and I've considered putting them on my xs b/c I get sore and stiff from sitting in one spot too long. I've done lots of things other guys think is shit, and I've seen other bikes that turn my stomach, but when it comes down to it I respect anyone who turns a bike into what they want it to be.
Ride On, just do it carefully!