One word really, choice. We do it the same reason why Ford makes so many different types of cars and trucks. Someone looking for a smooth quiet ride probably wouldn't be happy in a 4X4 Turbo Diesel.
Having that said, you can pick and choose the type of gains you're looking for and the features that best suit you, rather then us pre-determining them for you like other companies do. Check our search by bike engine at the top of your screen to help identify what we have available for your machine.