This trail might be one of the best hidden gems in the northern Front Range. Dadd Gulch is fast, fun, has a bunch of stream crossings and is far enough away from any major cities that the traffic on trail is minimal. The ascent isn't very challenging and there is only one portion that exceeds a 17% (guess) grade. Once to the top of the trail you have the option of doing a lariat on not well shaded fire roads or bombing back down the way you came.
The descent is fast, flowy, but not too steep keeping things well within intermediate difficulty. The streams keep you cool and the lack of foot traffic keeps the descent continuous. Also, there are many small jumps that are either water bars or have been built by others that can be used to get a little air time.
All in all, it's a very fun trail and worth the drive. Link it up with Hewlett Gulch on your return into Fort Collins for even more singletrack.