You already know how we feel about 650b tires. If you don't just google 650b and it should become immediately apparent. You can call it 27 point whatever if you like. So when we decided to introduce a new size for the San Marcos frameset, we went with 650b wheels.
As you may know, the San Marcos was designed by Rivendell and uses their lugs, but with Tange Prestige tubing like our other frames.
The current crop comes with a more Rivvy, frenchified fork, that we think looks great. Overall it's similar to the late Bleriot of yesteryear, but with a few nice features like front rack eyelets and a kickstand plate.
It's not low trail. That's kind of the point. The San Marcos doesn't need a front load to stabilize the steering, but it will still accept one as long as you remeber to steer the thing.
All the 650b San Marcos frames also fit Soma's Cazadero gravel tires. Now you can really have one bike for road riding, touring, brevets and commuting around town.
Even though the San Marcos is probably the coolest frameset we've ever made they just don't sell enough units to keep the project alive. So if you think you'd like to own one of your very own to keep and cherish forever and ever, you've got until the current batch runs out to make up your mind. Once these are gone, that's it. The San Marcos will be going to join the XO-1 and the Saluki in the place where awesome bikes go when they don't get the love they deserve. But don't worry too much, cause we still have a few.
More pictures of the builds from this post can be found at American Cyclery's Official Flickr account.