Plymouth to Kingsbridge route - please help

[Fandango]

I am cycling around the coast of the UK in stages and at the end of May it's Cornwall's turn. The hills look rather scary but so does the route from Plymouth to Kingsbridge. I like to avoid all A roads but this doesn't seem very easy to do on this stretch and the A379 seems the only way to go

The Sustrans site shows a proposed route that avoids the main road almost all the way to Kingsbridge, but is this ridable in any section on a touring bike? I'd be very grateful for any local knowledge here as I don't fancy a day on the A379 much.

 

[ufkacbln]

Although it was a few years ago, I just went for it... it wasn't too bad

 

[Fandango]

Although it was a few years ago, I just went for it... it wasn't too bad

It looks quite narrow in places, I tend to walk a bit when loaded up and Cornwall is pretty hilly so I might be blocking the road a bit. It's not purely about the danger though. I have a day to ride from Plymouth to Kingsbridge and I'd much rather see the quieter side of the area and take my time. If I go on the main road I will be there before lunch and have an afternoon free in Kingsbridge, not sure if that's good or bad. The proposed Sustrans route looks great, I just can't tell if any of it is ridable yet.