Hi,
When I bought my B40 (late last year) it was fitted with a Taiwanese Chen Shin 3.25x 18 on the front and a Dunlop on the rear. The Chen Shin is a fairly conservative looking block tread.
I only rode it about fifty miles home, before stripping it for rebuild. They seemed absolutely fine, but I obviously wasn't being particularly adventurous, having never ridden the bike before.
The front looks brand new but I'm not sure about the rear. There's virtually no tread wear, but the sidewalls could be showing a bit of age.
If you want pictures (or to buy them for that matter, I'm rebuilding mine as an Enduro(ish) so I won't be using them) then give a shout and I'll sort something out.