I am getting a squeaking noise coming from the front wheel of my 2001 Custom Sportster 1200.
I tried spraying WD40 into the bearing (and keeping it off the brake system), but this did not seem to help. It does not make the noise when I wheel the bike backwards.

Any suggestions of how too isolate the squeak and fix it?

 

Umm, I'll take a guess and say maybe some grease would help?

 

+1 - Washing the grease out of the wheel bearing with WD-40 is not the brightest of ideas.

If it's only squeaking when you roll the bike forward and not when rolling backwards, the first thing I would check is your brake pads & caliper.

 

+1 on the brake pads.

 

I would remove the pads and then roll the bike and listen for the squeak.

 

Rebuild the caliper. The seal isn't retracting the piston, keeping the pad in light contact with the disc.

 

+1 I recently did this on both my brakes. The pistons were so coated in @#(% that I had a heck of a time getting them out even with the compressed air. Rebuilt caliper and new pads = no drag/noise, and much more effective brake application.