Originally Posted by
fronesis
1. The notion that there is something wrong with Shimano chains, especially that they are prone to breaking, is just nonsense.
2. The torque spec for thru axles is very high – usually 15Nm. Please make sure you didn't UNDERtighten what the mechanic had done properly. I've seen people back off the tightness of a thru axle to fix a rubbing rotor, only to have the axle itself come loose. Get the torque spec correct, and then re-center the caliper on the rotor.
3. I've got half a dozen hydraulic brake bikes, and the "tolerance" for the gap between rotor and pad is no different when the pads are new than when they are worn. The nature of hydraulic calipers is that they auto-adjust to keep the same gap. So if it's rubbing to start, then the caliper is not centered properly on the rotor (see 2).
The guy based his opinion on Shimano chains on customer experiences I guess and rates KMC higher. I am just glad I don’t have a crap chain. The torque spec is 11nm max. It is written on the outside. The mechanic had it slightly too tight and easing off slightly and recentering (loosening caliper, retightening etc..) cured the rub. I checked the spec later. Of course the rub was minor but was something my last Topstone would do too until the pads wore in. On the new bike the callipers did not adjust immediately as the left was a little sticky.