Is This The Reason Behind Optimus Prime's Disappearing Stripe?

[LBD "Nytetrayn"]

There has long been a strange aspect of Generation 1 Optimus Prime that has always bothered me: the stripe across his chest that disappears when he transforms into truck mode.

At least, in animation, it does. Here's the toy:

And here are some samples of the animation:

Now, it didn't always happen...

...but it happened enough that even the movie did it in one of the most famous Transformers scenes of all time:

Look at that. The stripe practically grows out of him when he transforms to robot mode.

I've always wondered about this odd animation... mistake? Was it an error? Or a design choice?

Then I saw something in a video recently which struck me, as it could provide a piece of the puzzle:

Behold: The original Diaclone Battle Convoy. Notice anything peculiar here?

Yeah. He has a stripe across his chest in robot mode... but not in vehicle mode!

Could this image have been used as a reference for the people developing animation for Sunbow?

Or maybe it's just a really peculiar coincidence surrounding a strange set of circumstances.

Anyway, that's just a theory... a Transformers theory. Just please don't tell me if someone else has already pointed this out... unless they found a definitive answer, then tell me.

(Also, if they did use that Diaclone image, they clearly didn't pay much mind to the top-left corner there.)

 

[Sabrblade]

Here's Optimus's final character model:

Notice the stripe in robot mode but the lack of it in truck mode.

Looking at his pre-final models, the stripe was present on his truck mode, but removed at some point during his model's development process.

Plus, as you mentioned above, the stripe was sometimes present on his truck mode in certain moments of the cartoon, most notably in episodes animated by AKOM, who used unusual color schemes for Optimus's character model:

 

[Blot]

You'll also notice Optimus has seems to have lines on his arms that evoke where the stripe winds up there on the toy, but remain solid colored on the character model.

 

[LBD "Nytetrayn"]

You'll also notice Optimus has seems to have lines on his arms that evoke where the stripe winds up there on the toy, but remain solid colored on the character model.

Aye, and I was going to point that out, but I figured that was consistent enough to perhaps be a conscious decision. I don't think I've ever seen those colored in.

 

[Dake]

I guess it would sort of make sense that the early toon models were based on the earlier-still Diaclone whereas the movie and/or later seasons had more recent designs to pull from.

When an entire trailer disappears and reappears - a stripe is nothing.

 

[tec]

I just want a high end Prime one day with square headlights