I am currently working on these guys' walkcycles... so?
(http://img224.imageshack.us/img224/7826/animation1rd7.gif) (http://img220.imageshack.us/img220/8136/animation2qh4.gif)
The one on the left moves too fast really, and I think that they might need more frames.
the first one walks a bit like he's kicking something.
Both fine walking animations. The guy on the right needs to have his arms a bit further apart imo and they both need a bob when their leading foot is the most strait.
I've got a bad cold right now but I managed to do a quick edit on the biker to give you some ideas.
1. Removed the face turning. People don't naturally sway their heads left to right when walking, and it looks unnatural in sprite animations. This is a style choice so you can do it your way if you still want.
2. Made the torso animate a bit more to emphasize his heavy movements.
3. Made him move down one pixel on a down step. This helps to give a real sense of motion.
4. Adjusted leg motion slightly.
(http://members.cox.net/progzmax/bikerguy.gif)
(http://members.cox.net/progzmax/bikerguy.gif)
I think you did a great job with the additional animations, so my advice is to focus on actual leg movements. Two additional frames might make it easier on you in this regard, since you can show more leg motion. Try applying what I have done here on the other animation and post your results. Nice work!