Here's my story....
I got a cannondale hardtail back in '99 which came with a 2x9 setup. It had 44/29 x 11-34, coda rings on coda cranks with a shimano square taper BB. The rings lasted forever, shifted great, but have since worn out. I rode this thing everywhere, commuted everyday on it, and reckon I did close to 15,000km on it. I kinda got used to 2x9.
Meanwhile, I built up an ellsworth, and went for the new XTR cranks when they first came out (early 2003). I built up the dream bike, but it was ruined by the performance/shifting of the cranks. I put up with them for over a year. I could never get them to shift properly (the chainline sucked, way too wide), found that I rarely needed the granny (nor could shift to it if I tried, most of the time), and then started getting chainsuck from the middle ring within 6 months, as it was wearing out really quickly. That XTR crankset has now sat in the cupboard for over a year, because I put a 2x9 setup onto it in mid-late 2004. At that time, I knew that I needed/wanted a 2x9 setup for the bike, and had a really good look around at what was available. I needed a 94mm BCD crank that had a narrow chainline. The outboard bearing stuff was out of the question (chain line too wide), but I did see the initial drawings of the FRM 2x9 outboard bearing crankset about to come out, but couldn't wait, and they are a bit of an unknown, as no-one seems to have them, no reviews etc. Even though I heard horror stories about ISIS, I looked at those extralite 2x9 cranks (not 5 bolt, but they make a 4 bolt 30T cog, couldn't get in 170mm), the middleburns (I think they had a strange bolt pattern, so it would be difficult to mix cmponents across my bikes), the race face Next LP ISIS (didn't have any 170mm left), the RF turbine LP ISIS, and the FSA Afterburner world cup which comes with the right rings (a 29T, and a 44T with specially designed ramps to suit the 29T). In mid-late 2004, I managed to get hold of a set of the very last turbines in my size, and a set of the afterburners with rings (thanks to larry finding them). This was around the time when all the manufacturers were changing over to the outboard bearing stuff.
The race face turbines went on the ellsworth, with the FSA rings from the afterburner crank, on a Race face signature Ti 108mm ISIS BB. I was was pretty damn happy that night when I went for a test ride, and am still smiling. Finally, I got the shifting performace that my hardtail always had. The ellsworth was finally "complete".
on the hardtail, the orignal coda cranks where taken off (now waiting for a donor bike), and the FSA afterburner crank when on it with a 108mm RF signature XS BB. I originally put a FSA 29T & Salsa 42T chainring on it, but had some strange slipping problem with the salsa chainring (the chain was jumping off the chainring under load, even when in a parralel rear cog), so I picked up an older model shimano XT 44T cog, and that worked pretty well - didn't shift quite as well as the FSA 44T cog though (near perfect). Since then, the hardtail has been retired from offroad duties, is now exclusively a commuter, and I've put on a road gearing setup: 46/34 blackspire chainrings and 11-23 shimano road cassettes (dura-ace & ultegra). I have had absolutely no problems with it, but I think the BB is on the way out, so I am looking at options for a high mileage BB - I'm pretty sure the old RF docs stated that bearings are replaceable, so I'm looking into that at the moment.
The kind of terrain I ride (rolling hills, no huge ones) means I almost never feel the need for a 3x9 setup, with the granny gear. However, I went in a 100km event last year which had 3 monster climbs where a lower gear would've come in handy, so I'll be slapping the XTR crank onto the ellsworth specifically for this year's event. Other than that, 2x9 all the way.
For the future, I'm very interested in hearing anyone's experiences with outboard bearing BB/cranksets, running a 2x9 system (that's the "XC" 2x9, which is a 29/30T small ring and ~42/44T big ring). Something like the FRM setup. I'm particularly interested in the chainline (must be narrow), and shifting performance.
