Drill the top of the main support bar, and run a nut/bolt through it...
LOOOONG BIKE ALMOST READY !
Seat post, saddle, cranks, chainring, chain, and fitted the rack - Made it out of an old lawn mower's handles. Easily clamped on and drilled some holes at the top and ran little nuts/bolts through to hold it... also, the bottom is slipped through the xtra-bikes bottom bracket !
I fasten it later with some wooden wedges and seal it into history using > ZIP TIES !<
I used two chain tensioners, one was from a dumpster bike (the upper made by KORE), and the lower is a GodSpeed which bolts to the deraileur hanger of the schwinn =)
The chain is made of two new 1/8 BMX chains.
The best part... taking the new cargo machine for a spin!!