I have a pretty good theory about the 3 Arcee bikes. A theory that is born from knowledge of how the production of the TF movies work, and not some random speculation based on "how things worked in G1"...
Trust me, I've been following this film as closely as Dr Lee and Nevermore.
Ok, does anyone remember the behind-the-scenes stuff on the bonus features of the Transformers Movie DVD? There is a part where Aaron Archer talks about the early Ben Procter concept design of Optimus Prime, and how they had to change the wheels because, in the design, they uncoiled. Archer mentions how something like that would have made the production of a toy nearly impossible, so they had to change it.
Ok, most people know that Hasbro has a say in the final movie designs, since they're the ones who have to make the toys - and they need to be do-able. Perhaps making Arcee three bikes solves one of the big problems Hasbro
would have with making a toy based on Ben Procter's Arcee concept:
If you look closely, Arcee's two bike wheels split apart. Her knees are two halves of one wheel, while on her shoulders are the other wheel split into
four - two quarters in the front, and two in the back (look closely at how her arms go
between the wheel halves). Now, Hasbro managed to make a pretty decent Arcee toy the first time around - but they only managed to split one wheel into two, and they had to hide the other in the back - with some clever design work to make it
look like she has wheels on her knees, but doesn't really.
Put yourself in Hasbro's place. Making Arcee into three bikes solves three problems at the same time:
1 - Her height is no longer an issue, as she probably will stand as tall as your average car-sized Autobot.
2 - If they release the new toy as three small basic/scout sized bikes packaged into one Voyager box, the bike modes would actually be
in-scale with the other vehicles, unlike the deluxe version.
3 - Instead of dealing with the six wheel-parts (two halves and four quarters) of the first design, they can now make a toy with a similar design without having to deal with the problem of wheels that need to roll but still split apart and move to all the right places on a toy.
Her colour scheme should remain pretty much the same, I just hope they don't change the bot design too much. It's really cool, and has already been so well established by the toy and numerous comics she appears in.