This was my first time riding the Massanutten. For those of you familiar with Duncan Hollow, they pretty much start from the same location. The trailhead starts from a parking lot right before the entrance to the Camp Roosevelt picnic/camping area near a red storage shed. Since the parking lot is both the start and end of the ride you can do it either clockwise (yellow blazed Stephens trail), or counter-clockwise (white blazed Massanutten Trail).
If you do the trail counter-clockwise like I did be prepared for a pretty intense uphill climb that will require as much endurance as technical skill. Many area's will require a little hike-a-bike. Once you reach the top of this uphill you will end up back on SR 675 on the ridge of the mountain. Take a left and about 20 yds ahead on the left will be the trailhead in the form of a fire road. This fire road; however, will soon dead end into another grueling uphill single track that leads to Kennedy's Peak. At the top you have the option of taking a short .25 mile hike to Kennedy Peak to a worth while scenic overlook.
Continue on down Massanutten trail where you will intersect with Stephens Trail (yellow blazed). Make that left on Stephens and you will be rewarded with a killer downhill that switches back and forth between flowing and small rock garden sections. This trail will dead end right back the parking lot where you started.
I ran into two other mountain bikers and we stopped to chat. They were locals that informed me that if I were to do it again I should do it clockwise since Stephens Trail is a bit easier to climb and the intense uphill section that I began with is a blast to bomb down. I also asked them on the comparision between Kennedy and Duncan Hollow and they said they would ride Kennedy all day over Ducan because it's more of a technical ride with not as many fire roads. I plan on trying this route in the opposite direction in the fall, but I still believe the agony of the initial climb is worth the long downhill at the end.
Bring plenty of water and stuff for mechanicals (I had a flat and busted chain) because it is some what isolated and few and far between with other trail users. Both horses and hikers are said to use the trail but I didn't see any.