hexron

Brand new Grand Cru Long Reach Dual Pivot brakes.The front brake seems ok but the rear just has way too much tension. Installed new cables, new housing. Then just checked by pinching the brakes together by hand. Took off all the cables. The front is easy to close on the wheel and the rear is ridiculously stiff - almost makes me think the brake is old. Again, these are brand new - less than 30mi.Is there some way to loosen the internal stiffness of this brake. Am I missing something?

blamester

Remove it and check the function. See which arm is tight
Should be easy to adjust but be aware there may be a grub screw to loosen.

JohnDThompson 

The first thing I'd check for is friction in the cable run. Is the housing too long, are there any abrupt bends or kinks? Once you've eliminated that as a source for the problem, then look at the caliper.

leob1

Try lubing the pivots. A drop or two of a light oil. It's a cheap and easy first step. If it solves the problem, go ride, if not you'll have to dig deeper. But since it's the back brake, no rush.

TallRider

You should be able to figure out if the one brake being tighter is caused by
a) spring too stiff
b) pivot(s) too tight
In the former case, the brake will pop open immediately when squeezed manually, in the latter case it won't.
Spring too stiff is an odd/rare quality control issue. Pivot too tight is something that can be lubed or loosened.