e*thirteen Technical Service Bulletin:
Summary: Certain Specialized bicycles may use a front derailleur mount that does not use the mounting offset speciﬁed by the Shimano E-type or Sram S3 mounting standard. As a result the XCX E-type chainguide will require a spacer and longer screw in order to ﬁt those bikes properly.
Identifying the issue: Both Shimano and Sram specify a 5mm offset between derailleur mounting screws. Certain Specialized frames do not use this offset. This results in the frames being incompatible with the XCX E-type guide as it does have a 5mm offset as speciﬁed by the standard. Many of these frames use a mounting bracket for the front derailleur as shown at right.
Recommended action: The guide may be mounted to the frame by using a 5mm spacer (not included) under the front mounting position. You may use the spacers that come with the guide for ﬁne-tuning the chainline as usual.
If using an added 5mm spacer and any of the included shims for ﬁne tuning, a 20mm front M5 mounting screw should be sourced and used to ensure proper thread penetration of the front screw.