You wouldn't be able to use an Ascent on a bus. It would be too stinky. It's the smelliest of all my vaporizers. You are talking about vaporizing while riding on a bike? The Ascent doesn't look stealth either, it kinda looks like a electric razor. Don't get me wrong, I love the Ascent I have. Not sure it would be the perfect riding companion.
The Air is a vaporizer that's stealth and has good flavor. If you wanted to use it while riding a bike I would suggest using a wooden stem, the stock stems are glass.
@Ed's TnT makes wooden mouthpieces for many of the vaporizers you see on FC, he is an FCer himself.
If you wanted to use a vaporizer on a bus I would use and ecig pen style vaporizer for waxes, oil or shatter. You wouldn't have worry about smell with people 1 foot away from you.
In many areas of the U.S folks can't use ecig vaporizer on buses. Folks are lucky if they can smoke at the parks in the Seattle area. I'm even hearing ecig restrictions. It's crazy how much control is happening with folks lives and their rights.
EDIT
I would suggest buying from an FC vendors that sponsor this website. You know you will be treated right, because if you're not we will talk about it here.