Snyder Trail or Knapp's Castle as its often called is a singletrack downhill trail located in Santa Barbara, CA that is usually done as a 2 car or shuttle ride. You could of course ride back up the trail which is about 3.5 miles or on the windy uphill road back to the top which is about 10 miles. This trail has a nice mix of fast and smooth straightaways, technical rocky sections, switchbacks and even some jumps. It's recommended that you wear a full face helmet and even some pads since there are plenty of places to hurt yourself along the way.
Knapp's Castle Video
Knapp's Castle Review
Snyder Trail is a pretty fun downhill trail but there are better downhill runs such as Mt. Pinos located in Frazier Park. So if it's not too far then it's definitely worth doing but if you have to drive too far to get there then maybe not so much. To get the most out of this trail you will need to do it multiple times to get the feel for it so you know what's coming up at all times. The top part starts out fast and has some jumps and is the smoother part of the trail. Midway through you hit some switchbacks which slow you down although there are some ways to bypass them and go through the switchbacks. There are also some technical rocky areas to deal with but they are not too bad and can be pretty fun. Near the end it gets a little rocky again before smoothing out at the bottom. One thing to be careful of is hikers coming up and down the trail. Most people are aware that bikers like to come flying down this hill and get out of the way but you want to make sure you don't have any collisions with anyone. The ride feels like it's over pretty quickly so that's why dong the shuttle thing is the way to go so you can do it multiple times. It's a slow drive back to the top and if you can get a designated driver to meet you at the bottom so you don't have to do the car shuffle thing then that's the way to go.
Knapp's Castle Pictures
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Since it's highly recommended to do this ride as a 2 car shuttle you will have to go to where the trail comes out on Paradise Rd. To get to Paradise Rd off the 101 Freeway exit on California State Route 154 San Marcos Pass Rd and head east towards the mountains (away from the ocean) for about 10 miles until you come to Paradise Rd and then hang a right. You will drive around 4 miles and then look for a dirt parking lot on the right with some barbed wire between it and the trail. There is also a house across the street so you can look out for that. After you park the car then take the other car back up Paradise Rd to the 154 and make a left back the way you came. Then you will drive around 3 miles and make a left on El Camino Cielo\Forest Route 5N12 and drive another 3 miles and the trailhead will be on the left. There will be places to park on the side of the road off to the right. The trail starts at the rusty metal gate right next to the road.