How can you tell if your rear shoe is almost gone ? According to the previous owner of my bike ,they adjusted it once already . The bike has 3800 mi on it . Thanks

No It's not squealing or anything ,but I did have to replace the front brake pads. I was just wondering if there is a way to tell.

you got about 15k more miles before you need to think about it at all.

I have almost 20,000 on my '87 and I just found out the rear brakes are fine. I thought they were worn out because the pedal was going way down and I had already adjusted the thing at the back as far as it would go. Turns out I either stretched the cable from heavy use or something else is not right. I ended up resetting the lever at the drum a few notches so I had more adjustment at the back. ( the shoes were almost as thick as the new ones )

The indicator marks on the rear hub don't line up where they should, which leads me to beleive the cable itself got stretched somehow. But by moving the actuating lever a few notches counter-clockwise, I was able to gain more adjustment. The actuating lever at the rear hub is clamped on the shaft. The shaft is splined. Unbolt the clamp and pull lever off--then move it a few notches counter-clockwise. This slightly relocates where the cam inside is, leaving the shoes slightly spread when in the at-rest position, thus seemingly giving you more adjustment at the rear adjuster.

It's a little hard to understand, but once you do it, it makes sense. It did to me. And it worked. I have rear brakes again, and saved $35 on the new rear shoes.