Originally Posted by labou1

OK, I just replaced the front tire on my 2008 FXDL and the bearings as well because when I put it on the balancer, I felt a slight clicking, figured for $10 it was worth it not to have a problem later.
Took it out for a ride and found that the disc is rubbing HARD on the inside of the caliper housing. Took the wheel back off just to make sure that both spacers are identical and sure enough, they are. I know you should not shim the caliper but I see no alternative. Shimming it .090" to slide it over, re-centers it but not sure it is a good thing to do.
Anyone out there have similar problems or have an ideas?
Thanks in advance

Originally Posted by parts eeter

I may be wrong or missing something here, but I have had this issue on my 07 Street Bob with both stock and aftermarket wheels. So I decided to tear into it a few weeks ago.
First thing to note that this a 4 piston caliper and the pistons do the centering.


The question being asked is regarding the centralization of the disc rotor in the caliper body.
In no sense do the pistons do the "centering" in a 4 piston caliper HD caliper. The caliper has a recess that the disc rotor passes through. The body of the caliper is positioned directly central over the rotor, which results in the pistons (at least initially with new pads) protruding an equal distance on both sides. Minor deviations in parallel alignment are allowed for by the "floating" rotor, which is how the concept of floating rotors came about.

Second The retaining pins were dirty. So I nice hand sanding and cleaning of the pads was in order. Brakleen the pads cleaned and lubed the pins with light grease and the anti rattle clips as well

Third. my master cylinder is new and my brake line is as well,new fluid


Your issue is clearly a different issue, being one of (supposedly) pads retaining contact with the rotor after application. I really do not see how sanding the pads would change that.



The problem DID get better and the rubbing was minimized,but it STILL exists. The only thing I can think of is the piston seals have worn thereselves into the caliper housing ever so slightly

I have no idea as to what this could possibly mean.


and the pistons arent returning efficiently.


This may be the case, but it is relatively normal to have some form of light grazing.


I plan on dissassembling the caliper and finish honing the piston bores.

And then, throw them in the bin, I assume, as that is all they will be good for.

The reason I posted this is because this is a 4 piston caliper I dont see how shimming the caliper will do anything at all.

It won't for you, as your issue is not an alignment one(primarily, at least).


The first time you squeeze the lever the pistons self align. Jap bike calipers actually float on mounting pins and self center VIA the pistons. The HD calipers are rigid mounted so rely on efficient piston return to eliminate rubbing.


All calipers rely on piston return to eliminate binding. That is why the groove that the quad seals are located has a relief machined into it, to permit deformation of the seal upon brake application, and, accordingly, piston retraction when the seal returns to its resting state. That is how it works.


If anybody has input on how they fixed their rubbing issues I am all ears. Feedback appreciated.

Originally Posted by cbz1200n

What bearings did you use? Did you press the first bearing in from the rotor side, then the spacer and then the second bearing? There is absolutely no reason you should have a fitment problem after the repair, did it fit correctly before the repair?

KYFATBOB, On the Fat Bob, what repairs did you make and then ended up with this problem?
CB

Originally Posted by KYFATBOB

No repairs, just put on a set of PM wheels and it was like that.