1/16" absolute minimum. I start looking for new tires at 2/16".
Took my new to the darksided 2013 F6b for a run over the holiday weekend to the NJ shore ... The intended purpose of my F6B is a highway machine , I have other bikes for back road knee dragging , tire sliding bikes .
I could never see putting a car tire on any of the light weight bike , as for the Goldwing series bikes can't imagine going back to a cycle tire on that machine .
I was running 32 psi but have had the tire aired up to 42 adds a bit more crown to the tire for more back road riding ... you can still do the back roads with the darkside tire .
Just my 2cents .
Question on this subject..
My front tire at 9200 miles is starting to cup. Bike still handles well and it's just the visual I noticed. I have been running it at 40, religious on checking tire pressure. Running the shock at halfway- a little harsh- but I ride the mountain twisties in between a couple road trips and want the additional handling .
It has always had a little headshake if I let go the bars at 30-40 mph.
Any ideas ?
Try 41 and see if it gets better. cueman