I have acquired a used XT 770 crankset. The big ring is trashed and I am going into sticker shock at Shimano’s replacement prices. Anyone have luck with other brands i.e. Blackspire, FSA, Race Face for this particular model? I have a hard time throwing down 60-100 dollars for a chainring that is not going to last long.
I sympathize with your plight. Shimano does seem to subscribe to the same OE replacement parts pricing as car dealerships and national defense contractors. The big ring on a 770 series crankset actually has a 104mm 4-bolt pattern, the same pattern used by most other brands, so other rings will match up, but be careful. Much in the same way you can’t imagine being married to a unicorn or living in a world where dogs can drive, Shimano can’t conceive of a world in which people buy FSA or Blackspire rings and bolt them to their XT cranksets. If you know the history of Shimano chainrings over the past few years, you’ll appreciate what a miracle it is that even the bolt pattern happens to match now.
So the good news is that nearly everyone makes an aftermarket 104mm bolt-pattern 4-bolt 44-tooth ring that will match up to the bolt hole pattern on your 770 crankset. The bad news is that it won’t work as well as the Shimano. This is partly because Shimano just makes excellent cranksets and chainrings, but mostly because all Shimano parts are designed specifically to work only with other Shimano parts. They don’t intentionally prevent other rings from bolting on, but they don’t test for them either. This means that, even if something else can technically bolt up, it probably won’t mesh all pro-like to the crankset’s spider–it will most likely be slightly too wide or too narrow, and some rings may even need sections filed down if they’re making contact with the Shimano spider or arm itself. Generally, a Shimano crankset with another company’s ring on it also won’t shift as well, because chains, chainrings and cranksets are one of the things Shimano still does extremely well.
So it comes down to you: if you’re the ultra anal-retentive type who demands perfection, you should shell out for the Shimano ring. If, on the other hand, you’re more the frugal rebel type who can smile while pressing a shifter paddle a bit harder to convince the chain to shift into a less expensive big ring, look for the most basic-looking 44t 4-bolt, 104mm bolt pattern ring you can find and get your rogue on.