"ttyIsland Hopper" folding bikes.. the "Mariner" is a 20" model with a Honda GX35 single cylinder 4 stroke.. runs about $700, new..
I got one used in NM for $200, but the carb needs a gasket.. I'll be replacing her when she pops out of the sky, though I could order her, if i liked..
we'll see.. (
http://www.motorizedfoldupbikes.com/ )
The engine configuration is a frame motor mount with a horizontal friction drive bar.
This makes the motor removable (pretty damn easy!!), without any changes to the gear & chain assembly..
I imagine a friction drive results in special considerations to the tires..
The one on this puppy are smooth, & clearly non-terrain, but they also are built like hell.. i'm guessing they have aramid walls..
As i mentioned, some fellow has done several circumnavigations of the US in a motorized bike, with a trailer (about 3'x3'x3'), so it's clearly doable on a *dedicated* vehicle.. i wouldn't want to tow anything larger than a child carrier.. a good motor & bike will wizz close to 300 pounds, total, at, say, 25 MPH, but you had better have a well built power plant.. no chineese knock offs (although check the Island Hopper site, because their cheaper version is a non-honda engine, and *nothing* in the construction of this one is shoddy or second rate, so their alternative engines are probably pretty sound, too).
Their bolt-on kits run from $300 - $550, engine included, depending on the motor used
It is a very, very easy assembly.. the throttle cable, however, do not appear to be included (just a simple sheathed cable), so you may have to improvise..
300 pounds is not a lot, depending on your size.. plus, if you push a limit like that, you are tempting fate..
As everyone above has mentioned, hitching with the damn thing would be impractical, but christ.. if you do even a gentle 20 MPH under load, it would be fucking kick ass...
DO NOT OVERLOAD DO NOT OVERLOAD DO NOT OVERLOAD DO NOT OVERLOAD...
did i mention... don't overload the poor 'lil bastards...
these things, 2 or 4 stroke, are air-cooled.. 10 degrees in ambient temperature makes a *huge* difference, especially if the air is dry..
i might try to make a little air scoop, for mine..
if you hit the desert, pay attention to her..
also, these things are not great at inclines, so be ready to pay the piper, if you do any mountain crossings..
friction drives are simple, but not efficient.. if you try & beat your beast, fully loaded, up trail too long, she *will* bite you..
once an engine is damaged & you get a ping in your valves, a rattle from your rings, or shake in any of your bearings, is does NOT go away, unless you hear it as it develops and is only a matter of thermal expansion and are smart enough to STOP MOVING and let her idle down, and slowly cool her off.. (idle down, run for 15 seconds, turn off.. wait 30 seconds, restart, run for 10 seconds, turn off, wait 45 seconds, turn on, run ten seconds (2 times) then off.
---- in fact if you suspect overheating early, go to idle, turn around & *coast* downhill, before performing your cool down procedure).
Also, you will need minor tools.. same as a full bike-road kit, plus sockets & wenches for your largest & smallest engine nuts/bolts.
IF YOU HAVE NO MECHANICAL EXPERIENCE GET AN OLD 2 STROKE LAWNMOWER & TEAR IT DOWN COMPLETELY AND THEN REBUILD!!
if you can find a busted 4 stroke, even better..
GET THE ****SERVICE**** MANUAL FOR YOUR POWER PLANT !!! (***not*** the "owner's manual", though you will need that, too).
It will pay to offer free clean up help or grunt work around a small engine repair shop, if they will let you assist while asking questions..
YOUR OBJECTIVE TO TOUR IS REASONABLE!!!
DON'T GIVE UP OR LOSE IT!!!
One last thing.. if you go with an externally mounted motor, see if there are any options for registering & insuring the thing..
you will probably *not* need a license if it is 35cc or less (dunno that for a fact), but you may get questioned..
insurance & registration as a moped or less (whatever the cheapest, legitimate options are) shouldn't run more than $100 a year..
use the engine serial #, if you need one for the paperwork, since the bike probably won't have one..
this is just a suggestion.. you may find the DMV too fucked up to let you do it, but at least *insure* the damn thing for the cheapest personal liability amount you can get... the point of this is not to protect yourself in case of accident (though it could help), but to give you at least *one* piece of paper to show the pigs when they will invariably stick their noses up your ass, wanting to see *some* kind of paperwork...
fuck.. even if you can just register the bicycle, it will make them feel like their doing their job, protecting society from *unregistered* fucking transients...
anyways..
that's my rant...
don't give up..
hope yer GF has recovered, and if you don't do it this year, use the winter to learn & gear up for next...
****you must have mechanical knowledge to do this****
if you don't, you'll destroy your engines & fail within 2 weeks of heading out..
good journeys, guys...
J
ps... if you get a 4 stroke, use synthetic oil!!
for 2 strokes syn oil is a bit of an expense.. the oil can cost as much as the gas..
4 stroke is def cheaper, generally more powerfull, & typically emission compliant, which *is* an issue, out west..