Originally Posted by outpost2015

This is the 'flow stem' which is standard on the Pro and Expert. The headset spacers are shaped as the stem, and lock in. The Concept Store were not much help. I've even thought about getting a local engineering shop to either reshape the conical spacer, or get them to make a custom one, so I can fit a shorter standard stem. The annoying thing is that the M size comes with a 90mm stem, and I even tried to order one, but no luck. The 2016 Pro and Expert look as though they have this also, so beware.