Bike conundrun

In the past, I have done 1 big relatively flat gravel ride a year using my fat bike (pugsley).  I am signed up for a few more gravel events this year and would like to do more of these types of rises, some of which involve a lot of hills and make the fatbike an un-ideal rig (event with 3" semi-slicks).  My only other "gravel"-type bike is a single speed all city nature boy. I recently tried to add gears to it via an old vassago gear-plug derailleur hanger adaptor (its held in place by pressure from the QR hub and via the tensioning screws that go through the track ends and thread into the gear plug, but the adaptor doesn't fit all the way back to butt up against the frame).  It seems to work, but I am not very confident of the set-up being out in the middle of nowhere and cranking hard on hills.

Don't really have the funds (or space) for another rig, but considering selling the nature boy (which is a shame because I like the way it rides and it has low miles...just shouldn't have gotten a single speed), any getting a cheap motobecane or nashbar cx frame.   But, that is a long term solution.

So, my short term problem is what bike to use for the events I'm signed up for in the next few months.  Not real keen on lugging the fatty up real hilly terrain. My other options are to 1) run the nature boy, as is, and hope my kludge rear derailleur set-up holds; 2) run it single speed and do a lot of walking (not quite in shape yet); or 3) use my old sh!tty 26er tailpipe-aluminium gary fisher wahoo that rattles my bones to death.

Any thoughts?

Sounds like the GF is the lesser of all evils -- just drop the tire pressure as low as you can

Is there a framebuilder nearby that could add a hanger to the dropout?

How about a dinglespeed to give you a bit more climbing range?

Internal hub? 

I cant put any more $ into the nature boy...already spent on a rear wheel and RD.  Here is the set up.  There is an opening in the adaptor that fits the tension screws.

As conversion by T_MB, on Flickr

I'd suggest just getting more miles on the now geared nature boy, so you can have more confidence in how it runs and have it set up well.  I don't think the Garry fischer or pugsley are good options, the nature boy setup single speed with a 38-17 or 18 would be better then those options.

go with the gear plug.