#1
I am curious regarding "FSA SLK tandem rear with a normal FSA SLK double crank arm system".
How will you mate the tandem rear (I'm guessing you mean the left tandem timing side arm) with the double crank arm? Did you know the splines on the double are different than the splines on the tandem timing arm??
If you have solved this crank mating issue, that is something I might be interested in doing too. Please provide more info.
Side note: I believe Ric at House of Tandems has done some of these mods, but that involved machining the splines to mate correctly.
#2
Have you researched combining the road r785 levers with Saint calipers?
My understanding is that the latter setup typically uses BH90 (higher pressure, lower volume) hose with a narrower bore than the BH59 (lower pressure, higher volume) hose usually used with the r785/XT caliper setup. Are you planning to test with both hose types, or already have the answer?