I just bought the 20S (2WheelPros) for $209 (No tax, Free Shipping) and I ran into the same exact problem on my RF-1200.
First, the speakers do not fit into the recessed ear slots. Just remove the thing gray foam ear pull and set it aside. You won't be using it. Use the thinner of the two velcro foam sets and place them inside the ear slots. You will have to use the double-sided thinnest velcro sticky first. The molding for the ear slot is different so you find that when you seat the speakers into the recessed ear slots, the section that has the wire will be slightly higher. Only fix is if you dremel/open up that spot more.
Second, unless I am missing something, there is NO WAY to clamp down the standard headset thing-a-ma-jig. The problem is that the two screws that tighten the clamp are in a bad spot and almost no matter where you seat the unit, the screws are hidden or unaccessible and you can't tighten them down.
The alternative I used was the additional bracket that you affix to the helmet via the stickey tape. This is a failure waiting to happen. I used this method and the Sena unit does NOT stay secure. In fact, the double sides tape is already peeling off the helmet within just 2 hours at the stickey tape side that sticks to the helmet. It is also pulling off the bracket. I would NOT suggest this method.
Althernative? Use the clamps and don't worry about sliding it up flush to the rim of the helmet. Just push it in/up just enough so the two small hex bolts that you will screw down are still visible. A shitty way of mounting it, but the only alternative I can fathom at this point.
Lastly, don't forget to go to SENA website and update your product. A few bug fixes. And when you pair up through Bluetooth, don't be disappointed how crappy your music "may" sound. But open up Pandora, iHeartRadio, or TuneIn Radio or the FM option and it gets damn loud!!!
If anyone has any other ideas how to mount it or links to videos or photos, please share. The double-sided tape bracket sucks and poses risk to lose your Sena unit at high speeds.
Last edited by GTS28; 07-14-2016 at 11:08 PM.