I'll try and get you a route slip for Sycamore Canyon. Since you're coming from Downtown, I'd suggest starting from Santee side (about 20 mins from DT) If you do the full course, it's about 19-20 miles with 90% of that on single track. Single track has some rock gardens few little drop into what used to be water crossing and alot of tight turns through the creek bed forest. I love riding there. It's a great place to have fun. There's a bit of climbing there too IF you want, but you are rewarded with a pretty Fast DH section.