So more rubber on the road? Can't argue with that.
I can!
More rubber on the road is not necessarily a good thing.
Just to simplify things lets say your tires have a 4 sq inch contact patch on ea tire. If your bike weighed 200 lbs you would have 25 pounds per sq inch downward force on each tire.
Now when you put your big fat tires on and increased the contact patch to 8 sq inches you would only have 12.5 pounds per sq inch of downward force.
Downward force on the tire is a good thing.
The more surface area you have on the concrete the more heat you create.
Heat is a bad thing.
I have heard the argument that race bikes have these gonzo tires on them so it has to be better. Most race tires have a U or even almost a V shaped profile so the contact patch is small to begin with and as you lay the bike over in a corner the contact patch will remain almost the same size.
And the tires are replaced long before wear changes the profile of the tire.
Most of the bikes with gonzo tires on weigh quite a bit more than our Enfields to start with.
So as far as to why Enfield went with the 18" tires on the C5 I don't know. I doubt if you would be able to tell the difference one way or the other.
The tire selection does not seem to be much better than the 19" ones if you want to stay with matching sets of tires.
If I had my choice I would have had a 3.25 x 19 on the front and a 4.00 x 18 on the back. Just like my Trumps have. Lot's of good tire choices for that combo out there.
All that said I just put a set of Avon RoadRiders on my G5. 90/90 x 19 on the front and 100/90 x 19 on the rear.
The jury is still out on them. I have a few concerns about them that I haven't justified in my mind yet. I have heard great things about them but............
CJ