Found a great deal on a frame with a 1.5″ headtube but still love your 1-1/8″ fork? Your swap will require a reducer headset, and you might need this Cane Creek Crown Race 1.5″ – 1-1/8″ Conversion if you are piecing your parts together.

Fitting on the fork crown, this race will allow the use of a 1-1/8″ fork in a frame with an inner lower headtube diameter of 49 millimeters (external bearing cups), 52 millimeters (integrated bearings) or 56 millimeters (internal bearing cups), commonly referred to as 1.5.” Compatible with 36/45 degree lower headset bearings only.