Originally Posted by KC8QVO

Excellent point.

I have had my eye on an ECR for a few years now. When I can swing it that is my "dream build". The wheel sets are the magic to the versatility. The limitation on that bike, and the Pug, is the upper tire clearance. You can't put a fatter tire on than what you can squeeze between the fork and seat/chain stays. However, you can always go smaller.

I did email back and forth with Surly on the ECR idea and the one caution they threw my way with thinner tires is the overall rolling diameter of the wheels - if it is much smaller then pedal strike becomes more possible/probable when cornering. I am not sure how much of an issue that would be, in practice. However, it is good food for thought - not just on the ECR, but any bike which you may have varying wheels for varying purposes.

The "fat bikes" might not be a good option - they are overly specialized, in my view. That is where the OP's Troll and the ECR really excel - they are far more versatile. If you build them with lots of gears and disk brakes the wheel sets are where you get a ton of flexibility.

As far as riding position and handlebars - if you are off-road in ruts and soft ground I'd say a wider straight bar might be advantageous. That having been said, don't discount the ergonomics of butterfly, bull horn, trekking, and drop style bars. The hand positions can be a blessing, same goes for posture changes. You don't want narrow road bars, though with as much off-roading as will likely be encountered by the OP.