Stuttering front disc brake SRAM Rival Centerline X on LCR017-D

[heljan]

I finally finished my bike a couple of weeks ago. On my first rides, I had issues with my front brake: it stutters when breaking and it gets more intense the harder I brake.
I tried a couple of things like checking that the disc is clean, sanding the brake pads, re-aligning the brake multiple times, checking that the disc is not bent. Finally, I bought a tool (https://www.bike-components.de/en/Birzman/Clam-Disc-Brake-Gap-Indicator-Assembly-Tool-p53339) to help me aligning the disc. I did a short test and it seemed to work but after three times hard braking it was back again.

Anyone experienced something similar like this before? Any suggestions what else to do?

To me, it seems to be a problem with aligning the disc correctly; the brake must have changed position when braking hard.
I followed the mounting instructions of SRAM and there Newtown meter values when installing the break. Does it makes to increase the torque by 1 or 2 Nm? One idea I had while writing this was using Loctite - does that make sense?

Thanks a lot for any suggestions!

[TidyDinosaur]

Are you sure it is not a loose headset? I had this with my gravel bike.

[heljan]

Thanks, I will definitely double-check.
My rides felt normal otherwise but the brake power has quite some leverage through the fork, right?
Did you "feel" anything while riding?

[Serge_K]

+1 on the loose headset. Be careful, because that sounds like a bad case of headset play. The sort of thing that prematurely wears out a carbon steerer. If you're really heavy and really unlucky, you end up snapping the steerer, jump over the bike, and have a really bad day.
Given you're on a lightcarbon frame, it's probably user error rather than bad tolerances, so should be an easy fix once you find the issue.

[TidyDinosaur]

Thanks, I will definitely double-check.
My rides felt normal otherwise but the brake power has quite some leverage through the fork, right?
Did you "feel" anything while riding?

I did not feel anything while riding, but the fork began to "stutter" when braking. I also thought it was the brakes, but it appeared to be the play in the headset. It was a very small amount of play.

[heljan]

Thanks! I was busy today but will definitely check it out this week.

[PLA]

I'd try a different front wheel

[heljan]

Today, I finally checked the headset. I could indeed hear some grinding noise and so I adjusted the headset.
I did some test rides: When breaking abruptly and hard, the break reacts well and there is no stuttering.
But when breaking with a bit more feeling and less power, the stuttering is still there (see attached)
I adjusted the break once more but it didn't make any difference.

Any other suggestions?

@PLA: Could you please explain why to change the wheel?