Hi everyone folks.
I need your help.
I have a trouble with my 2000 fatboy. I install 21" Ultima front wheel, new brake disc and and pads. When I brake from the front comes an aweful noise, like a horn.
You can ear it in the video below. When I bought the bike, with stock front rim nothing strange happened while braking. I have made several tries, in fact, actually I’ve made all the possible attempts with no goals. I install old brake disc and pads on new rim and the noise still remains. Finally a reinstall old stock rim with new pads and noise disappeared. So I think the culprit is the front wheel, maybe the spokes.
But how and why?

 

Brake grease on the rear of the pad might help.

 

new wheel hub may be slightly different, thicker or thinner or you may need to shim your caliper. your spacers might be off too.

 

Check if there is play on the wheel, are all the bolts tight (both of the caliper and the axle).

The brake pulls on oneside of the wheel, so this may result in the wheel being slightly pulled to one side causing it to rub or pull on the bearings sideways, causing rubbing/vibrations?

Put it on a bike lift and work it with it on there...

 

Just tried without success

 

Maybe you're right mate, in order to install new 21" wheel I had to install axle reducer cuz inner bearings diameter is 1 inch and wheel axle is 3/4. Reducers has a 1mm edge to the outside that could caused a wider forks.
I'm making the spacers turn back to lower them by 1 millimeter and recover the thickness caused by the spacers. I hope to solve the problem in this way

 

All bolt are tight with torque wrench and there is no play on the wheel. I just lifted the bike on a lifter and wheel goes smooth without any noise.
Anyway many thanks for your suggestion

 

Try new pads.

 

It could be something as simple as a warped rotor. Regardless, the geometry of the parts are off. Not sayi g they wrong but something is not aligned

 

This happened on my rear wheel when I installed new bearings I did not correct seat the bearing on the rotor side of the wheel first (as per the service manual), and as a result the rotor was not perfectly lined up with the calliper.

I would not shim the calliper need to get the bearing on that side correct and depending on the wheel you may need a different set of left and right side wheel/axle spacers.