I get confused easy so I probably mis-read the posts with nice pix of more- aggressive-than-stock front & rear tires for the T-Dub.
What I found at Bike Bandit: in stock size/tead pattern (what came on the bike from Yamaha) for the front 130/80 18" there is the Bridgestone C66P TW31, that is a rounded profile "trials-type" (I'de call it....)
I have "issues" with this tread pattern on the fine sand and flour-like dust of the dirt roads I travel mostly on.
Stock front tread "skates" sideways across the loose stuff...
. (Front wheel "drifts" spook me when I'me on two wheels.)
A better pattern for my AO is the Maxxis 6006 130/80 18 (six double-ought six)
The problem I had was that this tire is listed as a REAR tire.
It also might be "directional", which would mean you might be better off mounting it on the un-driven front wheel in REVERSE if there is and arrow showing direction of rotation on it.
I believe the 6006 is called an "Enduro" tread, but it looks like a staggered knobby to me and is noticeably more aggressive thant he stock Bridgestone.
You can get a similar pattern rear tire, but I'me happy if I'me able to slide the rear and I think that the small motor will perform better if it can spin a bit rather than be hooked-up like a cog railway.
I had NO trouble with rear traction with the stock tire in the rocks once I had lowered the tire pressure.
Dunlop makes a similar size and pattern tire (Dunlop 606 ?) to the Maxxis 6006, but I think the Maxxis is a better tire.
If you can't find the tire and tread you want for your front 18", try listed under REAR tires.