Master Link and Chain compatibility issues
 

I have a new shimano chain (6-7-8 speed) and I purchased a master link (SRAM brand 8 speed). I tried fitting it to my chain (and to another chain that I had on a different bike, also shimano) and it didn't fit either; the shimano links seemed to be just a smidgen too wide and didn't allow the link to close. I read on another thread here that it'd be possible to attach an SRAM link on each side of the chain and just apply the master link to those; is that viable, worth it? Could I just slightly file down the links that don't fit (it seems like it's just a hair's breadth that's not allowing me to close it)? Will that significantly detract from the chain's longetivity? Any other solutions?

catch-22

If you could attach Sram links to the ends of the Shimano chain to use the Sram link, it would be just as easy to use the same system to close the chain.

I don't know if Sram makes a wider link, but a few others might. In any event Shimano does make narrower chains, and that might be the answer for you. The other, simpler, option is to buy a KMC or Sram chain which already comes with a matching link.

I personally wouldn't ever go filing on a chain. But I do remember hearing of drilled chains from the 60's to dump a few grams of weight.

If you don't get the answer you need here, I'll suggest a visit to your LBS. In the worst-possible-case that they want you to buy a new one, last time I bought one at my LBS, master links were pretty cheap.

Unusual that a chain would be classified 6/7/8 speed. Generally, they are 6/7 (7.3mm) or 8 (7.1mm) I'm thinking you are attempting to put a 7.1mm link on a 7.3mmchain.

+1, either way a 8 speed chain will work fine in a 6/7 system, i don't even know why are still making the 7 speed ones.

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