Originally Posted by
jonwvara
My feeling is that a Soma cage isn't really a "hack," in the sense that it's easily reversible (assuming that whoever does the modification saves the original cage). If switching derailleur cages is a hack, it seems to me that switching to an entirely different derailleur would also qualify as a hack. But either would work.
I don't mean to imply that any damage is done to the original derailleur, or that it is a poorly implemented modification. The Soma cage looks to be nicely executed. My objection is that the NR geometry isn't exactly known for shifting well (although it does well enough on my 13-24 tooth freewheels). With the Soma mod, the jockey pulley is fairly far from the cogs, which is going to require noticeable overshift. Hey, we've all gotten used to some overshift when using friction shifting, so this isn't a huge problem.
Still... there are better solutions out there. SunTour derailleurs have the slant parallelogram to keep a fairly constant gap between the jockey pulley and cogs, and the Shimano design has the sprung upper pivot to achieve a similar result.
One argument for using the Soma cage modification is when you already have the derailleur that you will modify. You don't have to go out and find a decent SunTour or Shimano derailleur or worry about some unforeseen compatibility issue. I see a lot of SunTour Cyclone GT derailleurs on eb*y with (imho) crazy prices. If you have time to wait for a decent price to pop up, then you can do okay. If not, there is a lot to be said for just quickly ordering the Soma cage.
(but it still looks like a hack to me.
)
Steve in Peoria