I recently moved from NYC to SF and soon came to the (literally) painful realization that my TSR 2's gear range was inadequate for the hilly terrain. What's more, the S2C hub had become increasingly unreliable. After some research I decided to replace it with a SRAM P5. It's the only gear hub that offers more than 3 gears, includes a coaster brake, and still fits into a 120mm dropout.
Since there is no cable guide/stop on TSR 2 (S2C needs no shifter cable), this isn't a straightforward hub swap. Therefore I contacted the Moulton expert Mr. Metras and he graciously agreed to do the mod for me. It took him only a few days to build the wheel and install everything, and the result totally blew me away. I'll let the pictures do the talking (from front to back):
Cable stop 1 (secured with the front rack; if you don't have one, a bolt is just as good)
Cable splitter (only needed for separable frame)
Cable stop 2 (secured with a Herbie Clip)
2 cable ties
Click box and hub (dust cap not installed—space too tight)
The gear range is now 251% (32, 40, 51, 65, 81), much better suited for the city's famed hills than S2C's 138% (51, 70). The clicking sound P5 makes is more muted and pleasant. The braking "feels" much nicer as well. While the new hub is heavier, the lighter Velocity rim that Bruce used to build the wheel cancels it out. All is all, this is very nice upgrade. I highly recommend anyone who wants to give his or her TSR 2 a boost contact Bruce for a quote.