The two rims appear to be quite different.

The Sun-Ringle Rhyno Lite XL Rim appears to have a fairly traditional profile.


The Velocity Cliffhanger appears to have more of a tubeless ready profile.


So, mounting and removing the tires from the two rims would be different. In the first case with the Sun rim, you would remove the tire in the traditional way, work the bead loose all the way around. Somewhat push it toward the middle, but mostly just get it worked down onto the rim surface.

In the second case with the Velocity Cliffhanger, you have to be very proactive at getting the tire worked down into the center channel, otherwise it would be a bear to get the tires on and off.

See some notes about that rim here.
http://www.bikeforums.net/touring/10...29er-rims.html