I am by no means an expert, but I recently put those same brakes on my bike and after constantly fiddling with my previous brakes, I think that set-up is the key. The SD7's are set-up perfectly and now I'm never fiddling with adjustments. At worst I adjust with the barrell adjuster and make very minor adjustments to the spring tension screws, but not often.
My suggestion would be to take off the rear brake arms, unscrew the tension screws somewhat, but evenly, then put the brakes back on, same pin on the seat stay for each, make sure the pads are lined up evenly, then slowly make adjustments to the springs, untightening the tight side a bit, or tightening the other side a bit. I personally think it's rims loosing their "trueness" that impacts tension, so true them often...
If this doesn't work, then hey, maybe it is the springs.
My suggestion would be to take off the rear brake arms, unscrew the tension screws somewhat, but evenly, then put the brakes back on, same pin on the seat stay for each, make sure the pads are lined up evenly, then slowly make adjustments to the springs, untightening the tight side a bit, or tightening the other side a bit. I personally think it's rims loosing their "trueness" that impacts tension, so true them often...
If this doesn't work, then hey, maybe it is the springs.
