www.madmaxmovies.com

I just noticed for the first time that when dale goes down on the bridge and gets smacked by the bike in the helmet, he's got a red or orange ponytail going down his back (obviously not real hair).

...

It was a tail thing attached to Starbuck's helmet. (Forget the significance, if there was any? Just a Starbuck thing as far as I recall).
http://bavatuesdays.com/mad-max-the-art-of-the-stunt/

It should be noticeable in other scenes.

(The tail is visible in "my" little Kirks Bridge signature pic below right).

Cheers,
Dale