My big GSA rig on a lose rocky rutted road, with the biggest issue being too tall of a first gear. That happens to be an issue with the Urals too. Not a Mexican Freeway!
How fast does your rig go in first gear at an idle? I think my Explorer runs 6-7 mph off idle and barely have to feather the clutch to start.
Your CDT trip was what finally convinced me NOT to hack a bike with shaft drive. I could (but haven't) gear mine to have a "crawl ratio" that allows 2-3 mph in first. Yes, it would require a half hour sprocket change at the trailhead to avoid having a top speed limited to 45 mph.
This made me consider the same, and was why I did a bunch of asking around before hacking an Explorer.
I have the same GSA rig as Strong Bad, more or less, and I can crawl at about 11-12 mph. Why I got a ceramic clutch when the OEM organic clutch died. Not as good as a big rear sprocket but everything's a trade-off.
Same as Drone's, about 11-12 mph. I don't have a ceramic clutch, my tug still has the clutch it came with from the factory. Although I've not any issues with my clutch, after it getting hot enough to smell a couple of times, I consider it to be the weakest link and treat it accordingly.
Anyone hack'd a SOHC CB750? I only ask because... well... I have frames and engines and front ends and and and filling every inch of shelf space in my garage. I mean.. it's a big, fat, heavy-ass bike, and a poor choice for what I have in mind... but... use what you have, right?
As someone that considered the same path, I'd highly recommend buying a complete sidecar rig for your first one. Learning how to pilot it is enough "new" stuff to absorb at one time. You don't want to learn how to ride it and wonder "is it supposed to handle like this?" or "is this safe???" Some ideas for the future: https://advrider.com/f/threads/fs-fleabay-cl-stuff-goes-here.492526/page-577#post-35246002 https://advrider.com/f/threads/honda-cb750-sidecar-rigs-lets-see-them.897158/#post-21688699
The grade I was talking about was about 15-18% and it wasn't lose rock as much as sharp, slick hillside made of stone, that was wet. It was barely wider than the Ural, and was rutted so the center section was a lot higher than the tracks. There was nowhere to go on either side since there were trees, and the sides were much higher than the trail. You GSA is a great rig though, and you are right, it will go basically anywhere. You also can run car tires most likely and get some great tire life, and traction. I just don't like them for me as much as the Ural. The GSA will be more reliable generally speaking, ride better, and do freeway speeds, and go anywhere. The Gear Up puts a bigger smile on my face.
My understanding is that the old CB750's are easily hacked. Plenty of CB750 rigs pictured on the web. Almost sure that DMC will have a kit. You know about DMC, right?
I'm sure if you spend time searching 'round the 800 something pages of the "Sidecars- Let's em" thread you'll see em. The 4 cyl Honda and the Kawasaki engines were popular for Motocross or Scrambles dirt track racing more than for off road or "adventure" style rides. The Aussies embrace the big 4 cylinder Japanese bikes for tugs more than we do here in the States or in Europe. I think that for what you seem to want to do, the inline 4 cyl Honda wouldn't be a good choice as they have zero flywheel and very little low end torque. For technical off road you want as much low end as possible and a nice smooth predictable wide power band not what is known as a "light switch" power band that is either on or off. You don't want to spin the rear wheel and it would be hard to keep a light switch power band rig from doing that. All that being said, it would make a great tug for a road rig.
Alaska and Juneau can't get enough of it.. I take them everywhere now.. Triumph 900 scrambler w/ DMC side car. The DMC side car rig for the 1250 GSA coming in next week; then I can really take them places!!. Whatever the rig.. just do it and go. Heh.
Buy a used gear up and enjoy it. Mine helped to completely change my life in great ways that I would never have expected. ( See below.)
This would be fun for the money... https://seattle.craigslist.org/see/mcy/d/aberdeen-2015-scrambler-dmc-sidecar/7235837268.html
...don't know if the participle matters much... all my russian friends call it OOOO-Raaal.... some refer to the sidecar as a 'stroller' because that is what you put the kids in to go shopping.... we call it the russian station wagon or RPOC depending upon how its running.....
If you've got the sidecar inch, scratch it. You can recollect stuff, not opportunity/time. Now I haven't read every post in this thread but this is in the ADV FM, would check the boxes you have asked about. https://advrider.com/f/threads/dr650-sidecar-rig-south-central-pa.1469912/#post-41263419 Except the look of a Ural.
Not exactly our modern Urals, but I figure the modern ones would be equally capable once one's had enough potato juice.