Originally Posted by
SpeshulEd
Make sure that spacers can be used above the stem as well. For example, Cannondale says not use them above the stem.
See page 15:
http://media.cannondale.com/media/ma...rSixEVO_EN.pdf
Assemble the fork, headset, spacers, and stem without tightening the stem bolts onto the head tube. When the system is assembled, the carbon steerer tube should be 2-3 mm below the top stem. All spacers must be located below the stem and within the maximum stack height as shown. No spacers may be used above the stem.
Its different for every bike though. Fuji recommends a spacer above for their setup.
You're correct but it is more about just the fork than the whole bike. And more specifically about the type/design/placement of the expander plug used with the carbon steerer tube. If the expander plug is not designed to be used with the stem clamped below the top of the steerer, you can crush and damage the steerer. That is what the prohibition is really all about. I don't think it matters at all with aluminum steerers and star-fangled nuts.