I'm looking to build up a set of race only DH wheels. I want to run tubeless and I want the rims light. I plan on using these on our smoother courses so they don't need to be strong. Anybody have any experience riding on Mavic 819. Are they wide enough for 2.5 tires? These are the only UST rims that our light enough (465!). The 823 is too heavy (580g) / expensive / hard to build. I'm willing too pay more and have the tough build of the 819, but only if they are really frikin light. My other choice is the Rhyno Lite (550g). I've run these before on trail bikes with good results and they are cheap and easy to build. Keep in mind these are race only wheels for smooth courses.