I've been running 10W-30 in my Honda NC700X for 16K miles to get the best fuel economy I can as a commuter bike. It runs great, doesn't use any oil between changes and the oil is a dark amber color after 4000-5000 miles on the oil. I hit a sale on Amazon for a couple of cases of the Castrol 4T 10W-30 and used it exclusively in the NC700X. Many guys on the NC700X forum have accumulated much higher mileage than me on their bikes using 10W-30. So, with today's oil technology, I conclude that 10W-30 is a reasonable recommendation by Honda.Some times I wonder why HONDA recommend 10W30 and don't care about engine longevity.
That's a reason mention an example on another post...
XR650L (the same engine from 90's and today recommend 10W30, for environmental health and fuel economy... If engine wear shorter time doesn't matter... As a company I say 10W30 to all)
I will try 20W50 next time on my FMX 650.
With that said, I ran 10W-40 in my Honda ST1300 for 40K miles and am now running 10W-40 in my Africa Twin. Honda specifies 10W-30 for both bikes, but 10W-40 is more easily available than 10W-30 motorcycle oil in my area.