Route 90 along the Dead Sea has long flat stretches, and most uphill segments have a mild slope, making it quite convenient for biking.
It's a scenic route, with the Dead Sea on the east and the cliffs of the Judean Desert on the west. The road shoulders are wide and paved, which makes biking on the shoulder easy and relatively safe.
Bikes can be rented in the hotels of Ein Boqeq.
Nahal Bokek we found to be an excellent place to cool off after we have done either a night ride through the dry canyons of the Amiaz area (Nahal Pratziem, Nahal Sdom) or come off the very hot high plateau overlooking the Dead Sea.
There is a perfect small pool that is just big enough for a group of friends if you don't mind sharing. ^O^