I was recently reading someone’s travel story, on a GS I believe, where they had a flat on the front. They removed the wheel and carried it somewhere for repair.  When they reinstalled the wheel, it wouldn’t turn - kinda like yours, it sounds. Turns out they had lost a “spacer” in the shuffle. I’m not familiar with your front axle/wheel assembly, but this story I had read came to mind. 

@4949 Thanks - I have both spacers installed the narrower one on the brake side as manual states.

It's the brake caliper - I took it off and the wheel spins fine & when I put caliper back on and tighten it all the way the wheel locks up again?

Got it. Bled the brakes and undid right hex screw bounced front end tighten it again and now seems go to go.

Hmmm. I know nothing of your front end, but something has moved. Did the wheel work involve removing/reinstalling the disc? Could something have gone together wrong there?  Totally guessing. Someone familiar with your bike needs to jump in. 

Glad you got it!

@4949

You're right on. I guess the important thing is if you have your front wheel off on a disk brake bike make sure no one pulls the brake lever or all hell break loose.

There is also another possibility. The OEM flexible brake hoses are KNOWN to collapse internally. This restricts the brake fluid flow within the hose. The master cylinder (being a pressure pump) can force the fluid past the restriction. However, when the hand pressure is let off the op lever, pressure relief holes inside the brake master cylinder should allow the pressurized fluid to escape back into the fluid reservoir. BUT, there is no "pumping" action occurring in the reverse direction. So the hose restriction ends up retaining (trapping) a small amount of fluid pressure on the caliper. 

It is NOT the caliper's fault. It's a material failure in the inner-most layer of the flexible brake hose(s). You cannot see it from the outside. The problem is caused by the caustic nature of the DOT3/DOT4 brake fluid attacking the "rubber" hose over years and years. The older your brake hoses, the more likely you are to experience this. This is not a BMW issue, this happens to ALL brands of brake systems. It's only that most other motorcycle brands are dead and gone after 30+ years !!

Check out this article RIGHT HERE.

Hope this helps.

Thanks, both my R80G/S & R100S have stainless steel brake lines. I'm pretty sure what happened is while the wheels were off for two weeks - even thou I put a wood shim in between the pads - my son pumped the front brake repeatedly and a few times the shim fell out. I don't exactly know what happens when this occurs - but they warn you in the manual about it. After bleeding the brakes - the lever feels better than ever - going to go take it for a spin to check it out.

Here's a shot..........

Another .........

Really like that motorcycle!  It would have to be fun. 

It is a fun bike thanks - but I bet I've put less than 50 miles on - spend all my free time getting it it good working order - the past owner wasn't exactly on top of it.