Cool. That's a nice one. You know if that's sold/distributed in the US, and if so, how much?

I was kind of looking for something like what Rivendell has on it's Quickbeams that covers the entire chainwheel, maybe keeps dirt off the chain, as well.

Here it is:

http://www.rivendellbicycles.com/ima...ics/50-150.jpg

Anyone know if one can get something like this anywhere? Sheldon Brown refers to it as a "chainwheel disc."