Back to the main route again - extremely hilly!
I took a group of Americans here a few years ago. They were experienced cyclists who had ridden widely in the USA, Canada and Europe. At the end they said it had been the best bike ride ever. Fortunately the weather had been kind as there are often long spells of settled weather in the early summer.
The area falls into two parts as far as cycling is concerned: Coigach to the south is not dreadfully hilly. Cycling this is inevitably out and back. A rough track is shown on some maps leading from the road end east of Achiltibuie to the A835 near Strath Kanaird. This is difficult scrambling and taking a bike is out of the question.
All the same you should go to Altandhu, Achiltiebuie etc. There are some lovely beaches combined with distant views of the mountains to the north. There are also interesting places to visit.
Further north in Assynt it's sort of hilly. A B&B owner in Lochinver once told me that she was expecting a family from Surrey one evening. They planned to cycle from Kylesku via Drumbeg. They knew it was hilly but it was only 25 miles after all. She got a phone call at 3pm in the afternoon, they weren't even half way round - she drove round and collected them.
You should allow at least two hours for these thirteen miles. There are occasional views of the mountains and the road drops steeply to some lovely bays. There are a lot of lochans with water lillies. On the way you cross the River Kirkaig which is the walking route to Suilven. Lochinver is an important fishing centre. It also has the Culag Hotel, a good supermarket, a post office and a number of other shops. The youth hostel is four miles further on at Achmelvich. If you are a mountain biker you might be tempted to try a footpath shown on OS maps running between Suilven and Canisp. This is not a good idea. The access point has a sign: 'no bikes please', and in any case if you try it you'll be carrying your bike not riding it.
For the other parts of this route, click Related above.