I apologize if this is more of a question directed to the Downtube co. and friends, but there isn't much info on their site, and the S.A. site has even less describing the technology. Can someone explain the advantages of the internal hub? From what I can tell it's low maintenance and a bit heavier. Is it just a matter of keeping the gearing cleaner? The product page describes not shifting while pedaling... which seems a bit odd to me. I read one thread describing it as superior to regular gearing, but didn't go much further. Any info appreciated as I'm looking at the Downtube FS and FS w internal hub systems, thanks.