I recently purchased a 2015 TT Traveler trike which came equipped with a SRAM G8 Internally Geared Hub (IGH). I have some limited experience with the Shimano Nexus 8 IGH and the Sturmey-Archer 8 speed IGH, but know little about the SRAM IGH. While researching the topic on the web I visited the late Sheldon Browns excellent website. There I learned that the SRAM G8 8-speed internal-gear hub was introduced in 2013, (and the G9 in 2014). Production was discontinued in 2015 (for both). I'm not sure why, but my guess is that there were issues. I further learned that the SRAM G8's total gear range is narrower than that of 8-speed IGH's from Shimano and/or Sturmey-Archer, 259%.
The good news is that within that range the G8 uses an even series of small steps. The G8 is, then, best suited to urban cycling without steep climbs and to cyclists who are picky about cadence. The bad news is that I already believe the the wider gear range of the Nexus 8, at 307% (somewhat evenly spaced) gear range, was not wide enough for my taste. I have the Nexus 8 on my Rover, and I long for a lower low, and a higher high.
Initially, I thought I would go the inexpensive route and put a double or triple front chain-ring on the Traveler. I still might, but without being able to find parts or replacement for the hub itself sometime in the future, I thought maybe I would put on a hub which should be more robust, have a wider gear range, and still be in production. I have discovered that the NuVinci N380, and the Shimano 11 speed IGH, both sell new for ~$350. The 11 speed covers 409% gear range, and N380, as it's name suggests, covers 380%. There will certainly be additional expense: shifter, new rim (and probably new tire - any problem putting a Big Apple in the rear while using Marathons in the front? Should it still improve the "suspension" of the trike?) spokes, etc.
The question is, which IGH makes the most sense, if the goals are to be ready for "most" bike/trike trails, including hills. The plan would be to keep the SRAM hub on its wheel as a temporary spare wheel/hub should either trike ever need to be serviced. I don't expect many, if any, readers have experience with either, let alone both hubs, so I'm interested in opinions based on what you know/believe, and more importantly, why. If you do have experience, thats even better. I'm anticipating roughly a $600 expenditure.
All opinions and comments welcomed! Thanks in advance.