Joined: Feb 2012
Posts: 19,381
Likes: 5,527
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
If I understand things properly the reason that a carbon steerer has a max spacer above the stem spec is because most manufacturers want a reinforcing plug inside the area that the stem is clamped around the steerer. Getting a plug to sit down deep in a steerer is harder then locating it at the top.
Do we know what the OP's steerer is made of? Andy.