I can finally afford my grail bike, trouble is I don’t exactly know what it is. I want one bike with a Pinion gearbox, that will be used mainly for weekly, round trip commute 46 miles with seasonal snow and ice on 3 mile section with 7-15% grade, total commute with 3,600’ elevation gain; as well as weekend rides with lots of climbing, road and gravel. But will also be using for annual protracted bike tours in US & Europe, but not planning on technical trails. I have gotten by commuting when the roads are clear with a Specialized Tarmac, which I love, but has poor clearance so I can’t put studded snow tires on it, nor could I tour with it. So I’m considering the CO-MOTION “Divide” with P18 Pinion gearbox. But there are other CO-MOTION choices as well. Not sure about BEST wheel size, frame dimensions, etc. I am 6’1”, 225 lbs.
I have a Co-Motion Pangea Rohloff. It has the 26" wheel size. I get the inefficiency crack occasionally also. I can use slicks or dirt tires up to a "2.125 on my bicycle with 60mm wide fenders. I Ride mostly on rode but plan to ride some gravel in the future. You are about to purchase a very expensive bicycle and careful planning is very Important. I only saw one Rohloff equipped bike in the flesh before purchasing and ordering my bicycle. You need to decide on the max width of the tires you need to run and make sure the model you chose is made for this. You need to know the max diameter rotor the manufacturer recommends and will it fit your frame. There is only room for a 180mm up front on my Pangea. You will enjoy not having a chain, although more efficient when totally sterile. Belts shed garbage and last much longer. You will not miss missing gears and those awkward stops at the bottom of a hill when you are still in high gear. When I ordered my Pangea Rohloff around this time 10 years ago. The Rohloff has had no issues. I have rode 700c and 26" wheeled bicycles most of my life and really have no opinion about one diameter being better than the other.