I understand this completely. The questions I need answers to is several hundred like these:
Better to use small gears in front and big gears in back or larger gears up front and not so large in back?
-For loaded touring an acceptable range is 20-95 gear inches.
What math to figure if a chain will be too long or too short?
-Because chainstay lengths differ the chain is a 'to fit' item/
How to I choose for different geometry?
-Loaded touring frames are in the 71-73 degree range and also depends on the fork kick out. This is to provide stability when loaded with gear.
Why titanium? Why not?
-Ti tends to be flexy unless starting with a 6Al recipe.
Sidewall construction?
-Which sidewall?
Load bearing members.
-An off the shelf touring frame can be loaded beyond what's practical to pedal. Carriers usually have a load limit.
Width for wheels
-17.5-18 mm inner width to mount 28-40 mm tires
AND rear sprockets and how to calculate chain departures/binding on paper.
- I've no answer
How are crank sets made?
-Generally machined propriatory cast aluminum
.....and about a thousand other questions like these.
Brad