Brake callipers

My brake callipers seized up so I've had a new set of brake fluid hoses and my rear calliper professionally cleaned. Still finding there's resistance or drag on the discs and there should be none? - for maximum performance and fuel consumption. I'm guessing the pistons in the callipers don't retract fully enough and was wondering if a completely new set of callipers might solve this problem. They seemingly can't be adjusted like on a MTB. The bike requires a lot of effort to push back or forward (more so after it's been out in the rain and grit). When I removed the rear calliper I noticed how the rear wheel spun more freely, with less drag.

I'm wondering if this is normal or if it can be improved. On short country lane trips I'm getting 80-90 miles before half the tank is used but on faster motorway trips around 200+ miles total. My 5th gen got c.235 miles on motorway trips. I don't use the VTEC turbo much and don't make many trips anyway (except for essentials and maybe a solo camping trip in the summer) because I'm getting older and world wearier. But if anyone has read this and has any comments or thought on this, well, cheers! Happy riding

Hard to move back and forth is not normal.

Does the master's piston come back freely? Or does the brake lever stays a bit "loose/floppy"?

After a ride, feel the brake rotor. Burny hot is not good...

There should always be light drag, you wouldn't stop in time if there weren't.   The bike shouldn't be hard to push around though.

What you describe is definitely not right. I would take the rear caliper off and have a good look. Is the pad on one side much more worn than the other? If so that might give you a clue to which bit is sticking. I'm assuming it's only the rear you are concerned about. As Dutchy says, burning hot after a short ride where you don't use the rear brake is not good

Check the disc runs true. Does the drag go on/ off as you move the bike or is it constant? Given you've had this problem, I would check the disc thickness to see that it's still within wear limits.

Check the caliper slider moves freely ( so the caliper can float) and the rubber boot that covers it is in good condition. If not, clean up with fine emery or wire wool, regrease and re-assemble. Get a new rubber boot if needed. Wemoto are great for parts like that.

Place a piece of wood between the pads and operate the pedal. Pads should grip and then release slightly. If the pedal stays floppy or the pads don't retract, it needs a complete overhaul. Possibly new seals and wiper seals. Possibly new pistons if they are badly pitted. You probably should change the fluid as well as your final step.

A draggy back calliper can be caused by a partial seize of the secondary master cylinder on the left fork leg. Make sure that is moving freely (should be just a couple of mm) and applying and releasing the brake when you push the calliper forward then let it go.

Generally draggy pads can be caused by gunk building up in the piston seal groove; if you have that, the callipers need to be fully diassembled. the grooves need to be gently scraped clean, the pistons polished (or replaced if they are corroded) and then the whole lot reassembled with silicone grease or similar. 

If you're doing a full on refurb of the calipers, clean out the groove where the piston seal sits. The calipers can corrode behind that seal, it's like a light white powder. Clear that out as that dirt and corrosion can push the seal out just enough that the piston can't retract quite enough. 

Can you push the pistons in by hand when you've unbolted the calipers from the fork leg? You should be able to do, although one might be very tough as that would be operated by the rear brake so there's a longer circuit and there's the PCV and the secondary master cylinder and all of that. If you can't push them and make them move freely I would consider popping them out and cleaning the seal grooves.