Originally Posted by browneye
There are probably more (choices) but these are the common and popular ones.
I am experimenting with an IRC 8 on my Terra for this ride. It's knobbier than a TKC but has more rubber to the road than the D606. Since it's a 3.00 x 21 it is very slightly narrower than a 90/90, but it "appears" to be a decent compromise. I sure would like to find a good streetable DOT front knobbie in 80/110 size, but nothing like that seems to exist.