Hello, I owned a bike store in Wisconsin for 15 years. I would not jeopardize my life biking here (and I am a good biker), nor would the bikes be able to be repaired properly, and then there is the issue, as was mentioned, of size of families.
I am thinking of bigger cities as I write, however smaller towns would still have many of the same problems, and theft as well.
As you suggested bikes, it is apparent that you don't know the DR that well. (Certainly no offense meant.) You may want to talk to some of the local relief agencies to get a feel for what is needed. An internet search should work well to get contact numbers.
Hope I helped, tom ....to the people who posted inconsiderate remarks, WOW!!: This person is trying to help kids right here in the DR!!