I live in Largs. There is a fair amount of riding that can be done int the area.
Quick kelburn explore to get you started:
Go up the main entrance, get to the pay station, turn right and go along the gravel road heading back to fairlie, it’ll come to a hairpin to the left going back on itself. Follow that climb all the way up… It goes on for a good bit. Once you get to the top, you’ll come to a white building on the rot, and a small cross roads.
To the right goes to the house
To the left goes towards Largs and comes out at the hailie brae corner at the cemetery
Straight on goes through a field track and ends up at a wall
Go straight on till you get to the wall and jump the fence on the right and follow the new track to the right back towards fairlie… That track runs along the top line of kelburn estate. I generally follow it till you get to where the hill dips and cut back into the estate through old gates. Once back into the estate, follow the tracks in the direction towards Largs and as you come don them, you’ll come back across the main road ad that you did the big long climb up.
That should get you your bearings of the estate in general.
Also, there is the new wind farms… Access off the haylie brae road. Follow the track upto the turbines, and apparently there is a quad bike track that runs from them back down into kelburn estate. Nt found it myself ( not looked)
Basically look at an os map, google maps etc. Dotted paths are reasonably cyclable