Hello, Farhad , and anyone else interested in this measurement. Please, excuse me for taking so long to reply; I received my bike 2 weeks after your post, and I have been busy riding, tweaking, and upgrading - I am only now back in the forum to read and contribute.
Width - At least 2.6; possibly ~2.7
Rim - Rodi Tryp: 35mm inner width (stock rims on the R&M Superdelite)
I measured the tires with my metal tape measure, so this is not extremely accurate, but the tires/tyres appear to be a little larger than Schwalbe states - roughly 2.7 or so. One contributing factor to this is that I am running the maximum pressure (~38 PSI; I may 'round up' a bit), and have been for the past 5 weeks that I have had my new eSUB. I primarily commute to work, so I want to have the lower rolling resistance that comes with higher pressures. I have ridden some trails a few times, which are dry, packed, and have very few rocks and roots (here in North Carolina - U.S.). I have not lowered the tire pressure for those rides, and the tires grip very well. I ride on roads to go to the trails, and do not want to change pressures for the trails, and then pump them back up for the trip home (roughly 8 miles/13km). I have hit some loose pack sections, and Herr Watts likes to grip on that type of surface, as well as a variety of conditions - road, hard pack dirt, grass, some loose sand/mulch-like dirt, and...very small rocks (Insert John Cleese accent here; she's a witch!)
Road grip is great, even with hard cornering at high speed with plenty of lean-over; the outer blocks hold well during this type of maneuver. And, when cornering on trails, the outer (wide-spaced) blocks must be gripping very well into any loose surface I have encountered, because I have not experienced front wheel wash out, or back wheel sliding. However, I am a novice trail rider, so my speeds are not too high, and the trails I ride are rated for beginner and intermediate riders. Still, I have been increasing my speed on those that I have ridden a few times, and the grip is impressive. The weight of my bike (31kg) and me (95kg) might just be driving the knobs into whatever loose surface we roll into.
I see these as being fantastic all-purpose tires. While I cannot logically say that these have prevented many flats, along with the Tannus Armor inserts, because there is no remaining evidence of puncture items that are deflected, I did find a piece of glass wedged between the center tread blocks a few days ago. It did not enter into the casing, so the blocks likely prevented that from occurring. There is a preliminary test of the first layer of flat protection - tread blocks. Even though I will likely keep these on my bike for approximately 75% of my riding, I did purchase a set of Marathon MTB tires for long distance bikepacking and touring, and also a set of Eddy Currents for when I build up my experience and confidence, to test my mettle on some tougher trails. I did, though, test these Johnny Watts on an OHV trail for a short distance, maybe just a mile or two; speed pedelecs (my bike is a class 3) are not allowed to be ridden on trails in our US national forest parks; although, it has been announced that this is under review for change). But, they are permitted on trails marked for Off-Highway Vehicles (OHV's). This was in the Uwharrie National Forest in North Carolina, and the tires gripped well in some gnarly, rocky areas. Yes, some ATV and dirt bike riders gave me some strange looks.
I hope that this has been some useful information for some of you. Selfishly, it was enjoyable to talk/type about it, but I would like to think that someone will see some useable information in this post; at least, I hope that you, Farhad, find the measurements useful now, even if this is a long time coming.