Originally Posted by
wphamilton
Those can be had, but it's ungainly due to the volume described by the various paths that the chain takes, and the gimmicky needed to avoid the front DR.
(they also need to be designed to a tighter tolerance. I tried a proof of concept on my derailleur road bike but it didn't turn out well)
So, by "those can be had," you mean "those cannot be had." Big, big difference between a chain guard and a fully enclosed chain case. The derailleur bike needs to be revolutionized, or perhaps scrapped in favor of a brand new design. IGH bikes are great but they are heavy and don't operate as well on uphill stretches as derailleur bikes. Maybe one day there will be a bike that has the best of both worlds (great on hills and zero maintenance with no need to roll up pant leg).