George raises some good questions. If you pushed the piston back in with crud on them, they can hang up on the seals. One thing to check first. Take a short ride and apply and release the front brakes. Now come to a complete stop using ONLY the rear brake. Then check to see if the pads are still dragging.
If, like most people, you come to a stop using the front brake, the pads may not retract fully. But a little "kick back" from the spinning disk may cause them to retract when you're actually riding.
Also, as Horst suggests, check to see how hot they get when NOT in use. Ride around for a while using only the rear brake. If the front disks get hot, you've definitely got too much drag.
One thing about brake cleaner: it's designed to clean brake DISKS, not calipers. The stuff is very hard on rubber seals, so if you sprayed it on the pistons and got it up inside where the seals are, you could have problems down the road. I use only clean (but not necessarily new) brake fluid to clean the pistons.