12-08-2019, 07:46 AM
MP that is a very detailed description of what you have done and found out, to add a bit more weight to the scale;
If the rotor is bent the opposite effect happens on the other side of the disk, the paper should free up some in the same place ( that you hopefully marked ), if it does not then it's not likely warped and repairable somehow.
( on my cb900 i could not tell the friction spots no matter how hard i looked at the disks and cleaned them, it just went away with new pads, lucky me ).
I think you found out more than the average service shop would, at least you've found the spot and direction of what pulses the brake, you also tried the old pads and found no difference, that's important and overall have established that this pulsing started after the tyre was replaced, also good information.
Would be a bit hesitant to sand the surfaces, you could induce some
'random"abrasiveness that would accumulate more friction in places and make things more complicated, i can't prove this but that is just my hunch.
As for the calipers; they are stationary and thus unable to "choose" a spot in the wheel to grip harder than other spots, what may alleviate things a bit is to check the right hand side pistons for free movement and free of dust and grime, all be it very small amounts if the pistons are not free to move that may play a part, like the rear caliper that's engineered to "float" sideways with brake pad wear and "self align" to the disk, alternatetively loosen the two bolts on the fork leg and give the caliper some wiggle room, don't forget to tighten them back up.
When you lift the front wheel does the disk drag in one place or are the pistons completely free, retracted and make no noise?
If the rotor is bent the opposite effect happens on the other side of the disk, the paper should free up some in the same place ( that you hopefully marked ), if it does not then it's not likely warped and repairable somehow.
( on my cb900 i could not tell the friction spots no matter how hard i looked at the disks and cleaned them, it just went away with new pads, lucky me ).
I think you found out more than the average service shop would, at least you've found the spot and direction of what pulses the brake, you also tried the old pads and found no difference, that's important and overall have established that this pulsing started after the tyre was replaced, also good information.
Would be a bit hesitant to sand the surfaces, you could induce some
'random"abrasiveness that would accumulate more friction in places and make things more complicated, i can't prove this but that is just my hunch.
As for the calipers; they are stationary and thus unable to "choose" a spot in the wheel to grip harder than other spots, what may alleviate things a bit is to check the right hand side pistons for free movement and free of dust and grime, all be it very small amounts if the pistons are not free to move that may play a part, like the rear caliper that's engineered to "float" sideways with brake pad wear and "self align" to the disk, alternatetively loosen the two bolts on the fork leg and give the caliper some wiggle room, don't forget to tighten them back up.
When you lift the front wheel does the disk drag in one place or are the pistons completely free, retracted and make no noise?