They both ride bikes and are on a mission.
A bike doesn't start singing when you put chains on it.
They both don't work without a chain.
You ride -- I'll go on foot.
They both can't ride a bicycle!
Invite two of them.
One if nobody is watching.
An hour 5 minutes for the Ramen noodles and foil. 55 minutes to fix the squeaky shopping cart wheel.
A pure bred meth lab.
They both ride bikes and go on missions.