Spyres. After checking the pads aren't worn out of course....First thing to check. When you start moving the lever does the lever on the caliper start moving straight away? If so all good, if not, tighten the cable. If the caliper lever moves more than about 8mm or so before the brakes bite (which it probably will) then the pads should be adjusted. You'll need a reasonably long 3mm allen key (to get through the spokes on the wheel side of the caliper) . Adjust each side evenly until the pads just touch the discs then back off a little bit. The adjustment is fairly coarse so just small fractions of a turn will do the trick. If you want to be fancy center the caliper. Loosen the the 2 caliper bolts a bit, squeeze the brake levers and then tighten the bolts while holding the lever. Check and re-adjust the pads if there any drag. If you really want to be fancy you can reset the centering completely. Loosen the mounting bolts until the caliper can just move. Screw the pad adjusters all the way out. Then screw them in equally bit by bit until they touch the disc. Squeeze the lever and tighten the mounting bolts. Then adjust the pads out until they don't drag. Looking down on the pads and disc, when you squeeze the lever, make sure the disc isn't pushed one way or the other by the pads. If it is, recenter it again, each time the adjustment will be less and less.