I never had this before. Very recent TRP Slate 4. Just put it on the SC with new (Shimano) hose and really good bleed, (I think).
Fantastic lever feel and loads of power but while braking I can feel a pulse through my finger coming from the lever, very weird. It *seems* proportional to the wheel speed.
New Clark rotor, which I took off and cleaned with brake cleaner. I also sanded the pads clean. Re bedded in which didn't take long but pulse back straight away even before the end of the bedding in.
Next step?
Thanks for any help.
Is the disc warped? Spin the wheel and look at the gap between pads and disc or put your finger against the caliper… is the disc catching the pads on the way around?
Not it's really well aligned, I always have tight tolerances and no rubbing. Have had much worse which even if I didn't correct never created pulsing.
I'd have also suggested a slightly warped or bent rotor. Can you remove it and place it on a flat surface to see if there are any gaps?
Rotor is installed the right way? The orientation of the disc might have a difference if the rotor needs to be installed with the arrow facing forwards (at the top) and it is actually pointing backwards.
Absolutely sure the bleed was good and definitely no air in the system?
Do the pads overlap either the wavy outside edge or the arms on the inside?
Do you have a different rotor to experiment with? Maybe swap front and back of they are the same diameter, see if the problem moves to the other brake.
Is the rotor from a genuine retailer?
I've had pair branded disc rotors new from eBay that look the part but are not the same thickness one side to the other. Maybe escaped production rejects or just counterfeit, l dunno. It was measurable with a micrometer.
They give a pulse through the lever that feels like the lever pushing back against you and uneven braking force.
Okay, seems like you've got to the point where we need consider unlikely possibilities.
Could it be that the top edge of the rotor is catching in the caliper? I've seen that happen before when the wrong adaptor has been used
I’ve had that on a bike with Clarks rotors front and rear. Replaced with alternative rotors and it vanished. Assume the Clarks ones had inconsistent thickness as the feeling was very pronounced.
I get this on a few bikes. It's only really noticeable when breaking smoothly for a long period of time. Down a road for example. It's never actually been a problem just a curiosity.
I would have thought that slight distortions in the disk would not do that? If a disc is off centre it is bent by the calipers?
I always assumed it was to do with changes in contact area. Because that would change the breaking pressure. Not really sure.
My guess is that K has the answer. Can you see a spot on the disc that looks different?
Bleeding will make zero difference to pulsing
All bolts torqued up? I assume they probably are, but it's been the cause of vibrations for me in the past.
I had this, it was the pads catching on the spokes of the disc. In my case it was quite pronounced as the disc was worn and the spokes were raised.