If they have time to be board, they will be.
Some people's definition of camping is just relaxing and doing nothing, sounds good to most adults (even me) but absolute nightmare for a kid of any age. Bringing the bikes along didn't do any good unless there was a special place to use them. If it was just around the campsite or RV park, they just stayed on the rack and never got used.
As many have said, have a plan and include them in it, if not let them plan it. May not be what you consider fun, but the memories of at least doing stuff with your kids while you still have the chance will be worth it.
The best times I remember camping and my parents remember camping were the times my sister and I got to bring friends (needed a tent for space but that was fun too), and also the times when we had a base camp but were always doing something or going somewhere. The stories we bring up and share about those times still makes us laugh.
My daughter 13 is hooked on Pintrest, and my son 15 is hooked on video games, but that is when they are at home and not doing anything else. Even if we aren't camping but just decide to take a day trip to a NP or even a Historic site, they finish the day thanking us for taking them there, while I am usually stressing over weather or not they will have a good time, they always do. Of course they would prefer an amusement park but mine understand about budgeting and why we can't do that very often.
I guess my point is that the more we kept things moving and not just relaxing, the less time they got to get board and then they were enjoying themselves more. Worked on me when I was that age too, even though we didn't have as much electronic stimulation as they do now, once my kids are moving they seem to totally forget about their internet and video games.