Again, no way I could get that rear tire spinning fast enough..."Hill climber" was my first thought too. Bonus: if the hill is steep enough, you won't be falling frontwards, you'll be weighting the front wheel!
Only 7" splined crank arms, and they are massive but lightweight. Yes Headbanger has a rear suspension. You could search "Headbanger" and go back to about page 4 to find my first build thread here in 2013. But this view with no chain shows it at the base of the Y frame, right above the kickstand.Dang, that layout makes the cranks look huge. How long are they?
Does the OCC bike have working rear suspension? I think I see a shock, but no pivot point for the rear end.
I've already done a guitar rack (and amp) bike.Most of the time I look at wide open front triangles in the frame and think, "What could I fill that with?"
On your BMMMMmmmmX I look and think,
"That rear triangle is begging for something!"
Maybe a vertical guitar rack? Or a single ukulele framed between the tubes? Skate board holder?