KMC chains totally compatible with Shimano/SRAM drivetrain?
 

The chain on my mid-90's era mountain bike recently broke. It's the OEM SRAM chain on a Shimano 8-speed drivetrain. I replaced it with a KMC 8.99 8-speed chain, but now I'm seeing a weird problem. If I pedal backwards, the chain downshifts to smaller cogs in the rear. Pedal forward and it jumps back up. I've made numerous adjustments but still happens. This doesn't happen with all the cogs. Also seems a little noisier than with the old chain.

Do I need to stick with an SRAM or Shimano chain?

Thanks.

Some people say to replace chain and cassette at the same time because they'll wear together. In other words, you may need a new cassette but now that you've used the chain with that cassette...well, I'm not sure how to put it, they wear in a way that the way they're shaped it's like they're shaped to go together. I don't know if I explained it well enough.

Yep, heard that advice. Chain wasn't too worn, though, as far as stretching, based on the stretch checking go-no-go tool I have. Cogs and chainrings look decent, too,

However, after some more digging here, I see that sometimes cross-chaining will lead to the behavior I described. The chain wasn't fully cross-chained (middle cogs with big ring) but once I switched to middle cogs with middle ring, I didn't see the chain jumping around when pedaling backwards. There's also a long discussion about whether pedaling backwards proves anything but I won't go there.

Pedal backwards and you can find a stiff or wonky section of chain.

Other than that, no reason to pedal backwards.

It was just unsettling to see that cog-jumping when it's never happened before with any of my bikes.

Thank GOD!! Someone posted about this issue, read up about KMC chains with Shimano drive trains. A lot of problems, I ALWAYS have problems with KMC chains. My problems are, the chain is louder, and worst of all is when I pound on the bike the chain will snap on the rear cogs and go down a cog set without me shifting. Its a problem with the chain because when I moved to sram or shimano chain, nothing but smooth riding and shifting. I advocate always riding sram or shimano chains for that reason. Its not like my issues happen with one drivetrain and 1 bike, its all my bikes that I've ever had. Also once my KMC chain snapped with about only 100 miles on the chain. Yep, KMC sucks.