Welcome to the Backroad Biker
The backroad biker is a place to discover rides off the beaten track in Shimane and other neighbouring parts of Western Japan. Since I have a car, the routes typically start from a good parking place - sometimes, in fact, the place will be the onsen/ryokan/hotel that you can stay in either the night before or the night after. If you have to use public transport you'll need to adjust the start points appropriately.
The routes are typically 3-4 hours or so of riding time, with stops for lunch, photos etc. not included. That's at an average moving speed of around 20-25km/h (12-15mph). Given that most of the routes involve hills, if you aren't used to a lot of climbing, you may find those times/speeds to be a bit optimistic. However do not despair, even if you go slower you'll still likely finish within 5 hours, which means a nice day of riding from say 9am - 3pm with an hour for lunch and other stops.
The rides are also generally not on major roads or through large towns - that's the whole point of "back roads" - and it means you'll not encounter that much traffic or that many traffic-lights and the like. However the downside of that is that the countryside is often lacking in conveniences so planning is required in order to have a decent lunch, not run out of drinks, use the toilet etc. However if you look carefully at maps and so on you will often find drink vending machines, bakeries, cafes, and public toilets apparently out in the middle of nowhere. Suitable places to eat/drink etc. will be noted in the route maps/descriptions.
If you look at the maps, many of these routes have alternatives, potential short cuts and the like. Feel free to vary them but do check the map carefully first. When I scout a ride I make frequent use of Google Streetview to check how narrow and poky roads are. This is a good first step, but it is important to remember that the streetview images are often a few years old and roads may have deteriorated in the meantime.
One thing that you quickly learn in this part of Japan is that what looks like it ought to be a major route often isn't. For example many prefectural roads (kendo - 県道) are very minor windy roads while nearby farm roads (nodo - 農道) are often wider and better. The same also applies in a few cases to national roads (kokudo - 国道). Sometimes that's a win, you'll see plenty of routes here that are on these minor kokudos or kendos, but if you don't check you can find yourself climbing or descending a steep, mossy and leaf covered single track road with no traffic, no houses and not much cellphone coverage. This is a bad place to be on your own and have an accident or an unexpected encounter with a bear or wild boar.