I have a used auto chain ajuster and the nylon (?) shoe has a few very slight groves in it from the chain my question is what amount of wear is acceptable ? It looks usable to me and was going to install it on my Deuce but with my limited experience wrenching on bikes thought I better ask first.

 

After initial wear from contact between the chain plates and the nylon you will find that the chain rollers will start running on the nylon as well and the rate of wear will decrese. I wouldnt bother replacing the nylon until at least worn half way through which should take 20000 + miles(only a guess base on wear I have seen as I never had to replace one.Its quite possible it could go double that).

 

"Grooving" normal wear pattern. When you can't adjust the chain to the proper tension then it's time to buy a new tensioner. 85K on my bike and almost there even with plenty of shoe left!

 

Thanks! thats what I wanted to hear. The guy I got it from had it on his bike for a week or so, was having shifting issues removed it and found the problem was something else and didn't want to go through the trouble of installing it again so I picked it up for cheap.