I feel that the Kancamangus Highway is fairly boring.
In my opinion, the best part of Rt 112 is the section WEST of Lincoln, NH. Also Rt 118, Rt 116, Rt 25, Rt 25C, and Rt 25A.... And, there are more.
If you want to ride to the heart of the White Mtns, (Conway, and North Conway), I strongly suggest riding Rt 153, and Rt 113 which are located on the border between NH, and Maine.
Rt 113 will allow you to pick up the, Hurricane Mountain Road out of North Conway.
I would ride into the "Conways" on Rt 153, ride the West Side Road around the populated area, come out in North Conway, stop at the scenic overlook of Mt. Washington Valley, then hang a right on to the Hurricane Mountain Road, and ride that to Rt 113, and ride Rt 113 up to Rt 2.
Ride West on Rt 2 to where you pick up Rt 16. Ride Rt 16 North to Errol, NH, then northeast into Maine and on to Rangeley, then up to Stratton, Maine.
In Stratton, follow Rt 16/27 south to Kingfield. Pick up Rt 16 and head south through New Portland, and towards North Anson. Just west of North Anson, pick up the Wentworth Rd, and follow that to the Cross Town Rd in Embden.
You are now back on Rt 16. Take Rt 8/Rt 201a into Solon. Cross Rt 201, on to the French Hill Rd. Then pick up the Hole In The Wall Road, (Dirt, but fine for all of your bikes). Follow the HITW Rd, to the Chapman Ridge Rd; turn left, then immediately right, on to the Valley Rd.
Follow the Valley Rd to Rt 151 (The Brighton Rd), and into Athens, Maine. Pick up Rt 43/151 and ride it to Hartland, ME. Hang a right on to Rt 151, and ride that to Palmyra and Rt 2. Follow Rt 2 into Newport. Pick up Rt 95 and ride it North to Rt 395. Ride Rt 395 to Rt 1A. Follow Rt 1A to Ellsworth, then Rt 3 to Mount Desert Island.
Let me know when you are going to arrive, and I will have a beer waiting for you.
You can return home by the coastal route.
I can do what I just explained to you, blindfolded. Those are "My Roads".
You will not be disappointed.
2007 DL-650 (I gave away in 2012 with 111,000 + miles)
"A word grows to a thought; a thought to an idea; an idea to an act. All the pieces are put together, and the whole is yours."
1942, Beryl Markham: "West With the Night"
"You can talk about doing a thing until everyone finally talks you out of it, or you can actually do the thing"
James Baldwin "Across Islands and Oceans"