Bornheim is asparagus country, and if you ride past the Kottenforst in late spring you will see why. The sandy soil on the Rhine terraces just south of Cologne suits the white spears perfectly, and from roughly April to the end of June the farm stands along the roads sell them by the kilo, along with strawberries that follow soon afterwards. This is the Vorgebirge, a low ridge between the Rhine plain and the Eifel foothills, long used for market gardening and orchards, and the Weißer Stein stop sits in the woodland at its edge.
The forest itself is a patch of oak and beech with broad rides cut through it, a legacy of the prince-electors who hunted here from the eighteenth century. The straight avenues radiate from old hunting lodges, and from the air they look like a pattern drawn with a ruler. On the ground you notice mainly the quiet and the smell of damp leaves. The tracks inside are meant for walkers, riders on horses and cyclists, so keep the motorbike on the public roads around the edge, where the lanes are narrow, lined with trees and occasionally rutted by farm machinery.
Alfter and Bornheim are both substantial towns, with twenty-two thousand and nearly forty-nine thousand people respectively, so fuel and food are minutes away. Bonn lies a short run to the east and gives you plenty more, including the Beethoven house in the old town and the Rhine promenade, which is a good place for a long, slow lunch. Bonn was the capital of West Germany for forty years, and you can still feel the faint, solid, civil-service seriousness in its streets.
The best time to come is in the shoulder seasons. In spring the fruit blossom and the asparagus sellers give the route a festive air, and in autumn the leaves turn bronze and the light is soft and low. Summer afternoons can be hot, and the road surface has patches of tar-melt in the worst of it. Pick a morning, eat something local, and let the Rhineland's gentle, slightly smug prosperity wash over you.