I'm not sure if that's technically Chromia's function, but she serves as Windblade's bodyguard in the IDW Windblade series by Mairghread Scott (which is where I know her from) so it makes sense to me.
For her vehicle mode, I used a Micro Machines Spider-Man Cycle. I don't know why Spider-Man had such a futuristic cycle, but whatever. I used green stuff to adjust the look and make it more Chromia looking.
As a side note, this may be one of the last Transformers conversions I do with a vehicle version. Micro Machines are pretty expensive, more so than most of the miniatures I use, so it's just not worth it. Going forward, most Transformer conversion will probably be just the robot mode.