Can't center front hydraulic break caliper

[Mitxel]

My dad gave me his Scalpel 29 4 2013 and I've been working to get it to a good riding state since it sat unused for a long time and the challenge I'm struggling with is disc brakes rubbing.

I learned to gravity bleed the brakes, and in the process I cleaned the bike, the calipers and equipped it with new shimano disc rotors and pads (my dad had uberbike ones, they were a little rusted and I wanted to eliminate them as a possible issue).

After getting the bike back together I used the whole loosen, hold brake, tighten bolt method for the rear, it didn't seem to work, I sometimes wonder if that method ever works. But after eyeballing it and adjusting it myself, to my shock I got it to spin perfectly with no rub.

But the front caliper resists my every attempt to center it. The wheel is a thru axle, not a drop out, and there's no play in it, I even bled the brake further to make sure the lever was as responsive as it could be. I tried a hayes alignment tool, I checked I had the right mount. No matter what I do I can't seem to get the wheel to spin freely without the disc rubbing. The amount of space I have to play with seems incredibly small, and the caliper mount even comes close to pressing into the rotor if I push it too far right.

My dad says he never got it to stop rubbing either, and I know he replaced the fork on this bike. But I don't know what to try next. Here are some photos, I don't know if they're any help.

[ReapThaWhirlwind]

Work on your alignment tool kung fu. It's a really touchy process, using the deep alignment groove first, then the shallow groove to fine tune.

It does look like you could be facing an uphill battle with that mount and the spacers under the mounting bolts. I can't verify it since I'm not there, but this could be impeding on the horizontal play that post mount caliper holes usually have for adjustment.

[Mitxel]

Still trying really hard to get this caliper centered with no luck, when I tighten the bolts as I'm watching and holding the caliper in my hands, it looks like the caliper moves over, as if the mount is pulling it away when I tighten it. It's why I wonder if I have the wrong mount but I don't know how to check. The fork had a 20mm mount similar to this I replaced it with this shimano 20mm because the bolts were wearing down.

[Talha]

Given that your dad replaced the fork, it's possible that fork alignment. . First, check the fork's alignment with the frame and ensure the caliper and rotor are compatible in terms of size and mounting standards
Use this video
https://youtu.be/j9qitEgmbow?si=4J5i0EzVEdltzmvw
You can also try adding a thin shim to the caliper mount if it's too close to the rotor.

[Mitxel]

Yeah, I've tried all sorts of things now, including adding spacers, either the hayes alignment tool or just using some card. Since I had an old mount I added the washers from the old one to the stack - this improved things greatly but at the cost of the rotor not being as deep into the caliper, the screws also aren't very deep in this configuration and part of the rotor still rubs.

I think at this point it's relatively safe to say something is wrong, something is out of alignment or the mounts need facing. So I'm going to try and get it to a local mechanic for help as I think the issue is beyond me which is frustrating since I feel like I was this close to riding the thing. Thanks for your help so far.

[rydabent]

The simple answer is to shim the caliper, to center it over the disc.