I would think if the bike sees a lot of summertime, city traffic I''d keep the shroud and forced air cooling as these engines are often times run within an inch of their maximum duty cycle, especially if climbing a long hill with a tailwind. I like the look of shrouded aircooled engines, and the whir of the fan means you know the engine is being kept cool. Besides if you take the fan and shroud off you have to come up with some sort of way to prevent clothing and other hanging bits from entangling in the rotating flywheel. And the biggest issue: how will you easily pull start the engine?
Fan shroud and striped both, he builds a lot of bike and races also............Curt