I was out in Briones this weekend as well, but I didn't take pictures, which is a shame, because it was lovely out there. I was also on a non-suspended fat tire steel bike, my Black Mountain La Cabra. My daughter gave me the book "East Bay Bike Trails" and I've taken that up as a script for my weekend riding. A Briones Loop was ride #6 in the book. I took extra credit riding to and from Briones from my front door as well, but the loop itself was definitely the burliest 10 miles I've done in a while. Some of those steeps are insane. At one point when a STEEP section flattened out a little, I sort of breathed easier and said "this is more like it, I can handle this" and I looked at my Wahoo, which said I was still on a 14% grade (!). Some of those pitches were >25% which is nuts when you add in the dirt and the bumpiness. I walked a number of the ups and a couple of the downs too! The green hills definitely made it magic.
Bill Lindsay
El Cerrito, CA