The real question is "why wouldn't you" tires need to be balanced for long life and wear, so why don't you balance them, as well, when you'r edriving down the road at 80 and your big 18 or 20" tires on your truck are going 80 and your 14" trailer tires are going 95 why wouldn't you???? The answer is, you balance your truck tires because you can feel it, balance your trailer tires because your boat does..............