Originally Posted by
3alarmer
...your link is to the SKS version of a fender for 26" fat tire wheels. You might be able to make them work on your bike, with the 27" wheels, but they will never work as well as fenders that are specifically molded and designed for 700c/27" wheels, which are curved in a more generous radius. If youi can return them to Rivendell, I would do so...unless maybe you are planning on riding different wheels as your commuter wheels. You can reshape them a little, using a heat gun, but it's an iffy process. You're better off starting with something closer to the radial curvature you need.
Dang it. Not sure how I pulled that off but thanks for pointing it out. They're still in the box so I'll be returning them!