I'm installing a pair of NOS Mafac RAIDS (identical to Racers, except slightly longer reach for 650B), and I'm trying to figure out how long I should set the straddle cable. My friend's copy of Barnett's seems to assume that the straddle cable length is somehow pre-determined and doesn't offer the same kind of step-by-step instructions for determining the length that it does for cantis. Sheldon's page on mechanical advantage is helpful in explaining the effects of adjusting straddle cable length, but I could really use some sort of rule of thumb to figure out where to start. To make matters slightly more confusing, I've replaced the stock Mafac cable carriers with Dia compe pully style carriers (which makes the angle at the top of the triangle slightly smaller than it otherwise would be). I suppose I can always just experiment with this myself, but I'm concerned about messing up the (potentially) hard-to-replace cables by pinching them in too many places (though I hear derailler cables work alright). Any hints or suggestions?