Thanks for the suggestions!So 4-5 hrs is standard. You can skip the southern loop (Woodstock loop) of the figure of eight and get in a 13+ mile ride (if you include going around the reservoir on the single tract) That takes 2+hours.
You can also go up Bear Wallow to the top, down "Hike a Bike" turn right and then up Signal knob and across Makena to bear Wallow and back down that . Its 12+ plus miles of almost all single tract. Mostly all in the sadle as well.
I did the standard EFurnace loop yesterday (without the Woodstock loop) it took me 2:30hrs with a snack break. Stream crossing were cold but doable, and trail was fast and fun.
While I have everyone in this thread... What other rides within 2ish hours from Northern VA are your favorites? (excluding bike parks). I did the SM100 this year and really enjoyed Stokesville.