No need for sugar; just take in some carbs, and if you are going for that long ride, some protein, to avoid scavenging your muscle. As has been pointed out, you can either use one of the many products specifically designed for it, or just add maltodextrin to your bottle. Lots of people have one bottle (or a pack) that contains the carbs, and one bottle that is pure water, which can be easily refilled. Of course you can also just stuff some food in your pockets. For me, that doesn't work so well when I'm on a fast ride - hard to handle and swallow - I need my carbs in a drink.