what is the difference between the SRAM chains?
 

(not including the hollow link one) they seem to get heavier (by 1-2g) and shinier as you go up the line. is there any other reason for them costing more as you go up the line?

You're correct, the biggest difference is the finish. For example, PC951 has all black links, PC971 has half black and half silver links, PC 991 has all silver links. I assume the silver coating adds the extra weight. Ironically, if you're a gram counter, the cheaper the chain the lighter.

Other than the finish, I believe there is no difference.

The other factor for cost is marketing, IMHO. I doubt it cost more than a dollar to go from manufacturing all black to all silver links, but the retail price difference is ~$12. If the retail cost was its true manufacturing cost, everyone would pay the extra $1 to get top of the line. However, by charging $12 more, the "perception" is you're getting a better chain.

It's more than perception.

Chain quality and cost is mainly determined by the quality of peening on the pins. Peening is what holds the sideplates on, and can vary from a single center punch to a double cross punch to a chamfered peen all the way up to a full radial peen. Hollow pins are tougher to manufacture so they cost more.

As for finishes, get the chain that fits your environment. If your chains tend to rust out before becoming worn out, get the one with the best rust resistant finish. If not, don't bother. If you have money to burn, buy the lightened chains. Taken care of, they last about as well as any other...they just cost more.

[QUOTE (by 1-2g)][/QUOTE]

If you want to get rid of two grams ,go the the restroom and do number 1 and 2.

If this is the case you don't do much riding.

I agree that the peeing process to secure the pin is very important. I'm not sure there is a difference with the pin peening on a SRAM PC951 or PC991. Their website doesn't mention it, and the photos of the pin heads look the same.

HAHA... You said "peen"

Or you live at the beach.

or you bike in the winter.