Originally Posted by
tatfiend
I have considered doing a touring frame build with the SRAM DualDrive and triple front chain rings. I have always thought that the DualDrive was a unique piece of engineering that has the possibility of extending the range of gears available for those who want an extremely broad range of gearing on a bike. 81 speeds has to have a ridiculous number of duplicates and overlapping ratios but makes a gear freak's heaven.
I had contemplated using a triple. But since I didn't want to spend the money on a new crankset, and didn't have an appropriate spare on hand, I decide to just convert the original to a double.
I did this back in July and probably have about 500 miles of varied terrain riding in it's saddle since. My observations: A triple would be overkill. The big chainring makes for a perfect overdrive to descend faster without topping out as quickly. Also, when on rail trails (i.e. flat rides), I only use the big chainring. I like it better for "cruising."
When I'm riding from my house, I'm still thankful for the smaller chainring, especially on the really steep climbs, rough dirt & logging roads, and off road paths. Also, since I load this bike up, for a trip from the grocery, or errands, and since I'm rather heavy, it's nice to be able to switch into the gearing needed for the particular ride at the time.
I'd like to see the DualDrive laced into a 700c or 27" rim and used with a double or triple on a touring frame. It would make a great deal of sense.
A challenge might be shifting all the gears. The DD shifter is really meant for upright and not drop bars. But a little clever tinkering could make this work (sorry for the out of focus picture, but the pebbles are pretty).
For instance, a 9 speed Shimano brifter should work the RD and cassette. The left hand brifter could work the FD on the double or triple crankset. Possibly a triple FD barend shifter (I'm thinking aero bars) could be utilized for the DualDrive hub?