Unrivaled mountain views, wildflowers, and pastoral beauty combine to a make one of the most scenic bike rides in the world. There's very little singletrack, and no technical interest to speak of, but the setting is pure magic.
You can start this ride anywhere on the loop. Staying in Grindelwald? Just start it there. Either direction works well too. And if you get tired, you can hop on the train in many locations and make it shorter, or cut off some of the vertical.
From Lauterbrunnen, save yourself about 1,500' of vertical and take the train (which takes bikes!) up to Wengen and start there (or just bike up the steep dirt road).
From the Wengen train station, follow the red "bike" signs out of town on the Wengen to Kleine Scheidegg
Trail, paralleling the train for a while. The paved road becomes dirt very quickly and passes in and out of the ski zone a few times. The scenery is just incredible in all directions. As you get higher, you pass through working pastures with the Eiger, Monch, and Jungfrau looming thousands of feet above. Those cows don't know how good they have it! Near the top, follow the train again for a bit until you get to Kleine Scheidegg - a good place for a break, food, and drink. The trail is occasionally forested, but is mostly exposed and quite hot while climbing. Thankfully most of the hills, though steep, are on nice tacky dirt and are very rideable.
Next, on the Kleine Scheidegg to Grindelwald
, follow signs from the hotel area to the red "bike" signs down steep dirt roads through the ski area. You are directly below some of the most impressive mountains on earth, including the north wall of the Eiger. Grindelwald is pretty in the distance After two miles, the road becomes paved and you can swoop down VERY fast. Be on the lookout for service vehicles or hikers. You now enter the forest and the views of Grindelwald actually become better. Pass through the farming village of Grund and speed into the lowest part of Grindelwald.
The best scenery is over now. For the Grindelwald to Zweilutshinen
Trail, follow the signs carefully and you'll be off the main road almost entirely. There are side roads, paths, and farm roads almost the entire way - keep you eye out for the red "bike" signs. This connector is easy, and downhill, with some pretty farms. The scenery and nature are pretty limited compared to other trails around here though.
Finish up the loop on the Zweilutschinen to Lauterbrunnen
Trail. Though lacking the grand views of the higher trails, this pleasant path goes right along the river on an easy crushed gravel path. It's mostly forested, with several bridges and a couple tunnels.