All component parts of the running gear are cast from nickel-silver for strength and durability.  All crank pins will be equipped with ball-bearings as are all journals.  You may notice portions of the equalized suspension above and behind the drivers, what you see are the real fabricated leaf springs and hangers.  You may want to review images of the first sample which shows more of the suspension detail prior to being buried by additional detail.  Also, notice the complete brake rigging and the reverse-gear linkage that will be electronically controlled for operation.