jbreebs
08-29-2019, 06:19 PM
My buddy recently came into possession of a Salsa Powderkeg, and now he and his wife want to convert it to a drop-bar gravel bike using modern components. I'm helping him decide what parts to use, and we've run into a few stumbling blocks.
He's fairly set on a 2*11 drivetrain, with something like a 30/32-44/46 crankset and 11-36(40?) in the back. We've run into two main issues - finding a rear der that can handle that range of gearing paired with a road shift/brake lever that is compatible, and finding tandem cranksets that will generally make that possible. The crankset arm/spindle (atleast the stoker chainset) needs to have mtb - width Q factor to clear the chainstays, as well as a larger than "mtb standard" chainrings to run the desired 32-44 chainrings. I've suggested that the new shimano rx/grx gravel group might work well on this bike - does anyone havee experience with this group yet?
He's also tentatively open to doing something like a 1*12 using sram axs, which will eliminate the cable tension issue, but raises other issues of its own (finding a super long hydraulic hose, and the crankset issue). This would probably mean something like a 40-42t chainring and 10-50 cassette.
I suggested possibly using two driveside arms from a cinch crankset, to run the normal chain DS and the timing chain on the NDS. This would require a right pedal spindle getting swapped onto a left pedal body, but beyond that I think it would work. However I've never messed with those cinch cranksets - can anyone verify that you could indeed put a DS arm on the NDS side?
Another option would be running both the timing and normal chain on the DS. If a 2*11 setup, using a triple crankset with the outer two chainrings as the main drive chainrings, and innermost chainring for the timing chain. If a 1x setup, using a 2x crankset with the inner ring for timing and outer for the main drive.
Does anyone here have suggestions? Have I not thought about anything; have I missed something important?
I've never done a tandem setup before, and while I'm fairly competent in component compatibility this is a little trickier than most projects I've worked on before.
Thanks!
He's fairly set on a 2*11 drivetrain, with something like a 30/32-44/46 crankset and 11-36(40?) in the back. We've run into two main issues - finding a rear der that can handle that range of gearing paired with a road shift/brake lever that is compatible, and finding tandem cranksets that will generally make that possible. The crankset arm/spindle (atleast the stoker chainset) needs to have mtb - width Q factor to clear the chainstays, as well as a larger than "mtb standard" chainrings to run the desired 32-44 chainrings. I've suggested that the new shimano rx/grx gravel group might work well on this bike - does anyone havee experience with this group yet?
He's also tentatively open to doing something like a 1*12 using sram axs, which will eliminate the cable tension issue, but raises other issues of its own (finding a super long hydraulic hose, and the crankset issue). This would probably mean something like a 40-42t chainring and 10-50 cassette.
I suggested possibly using two driveside arms from a cinch crankset, to run the normal chain DS and the timing chain on the NDS. This would require a right pedal spindle getting swapped onto a left pedal body, but beyond that I think it would work. However I've never messed with those cinch cranksets - can anyone verify that you could indeed put a DS arm on the NDS side?
Another option would be running both the timing and normal chain on the DS. If a 2*11 setup, using a triple crankset with the outer two chainrings as the main drive chainrings, and innermost chainring for the timing chain. If a 1x setup, using a 2x crankset with the inner ring for timing and outer for the main drive.
Does anyone here have suggestions? Have I not thought about anything; have I missed something important?
I've never done a tandem setup before, and while I'm fairly competent in component compatibility this is a little trickier than most projects I've worked on before.
Thanks!