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I just installed a new cassette Sram 990, Chain 991 Hollow Pin and new rings Blackspire Super Pro 26x38 and there is a vibration felt via the pedals when riding. The vibration is more noticeable the greater the chain tension and is felt at the same point in every revolution of the cranks. I can't feel it in the work stand. I have done the following to eliminate:

Adjust b tension to make sure cog and pulley are clear (but the feeling in the cranks is very similar to what this feels like but only at certain points in the revolution)
Adjust cable tension and limit screws to make sure chain shifts properly, it does under load
Adjust FD height to make sure it does not rub chainrings
Closely watch chain for a sticky link, there is no chain jumping/moving in pulleys
Verify chain line is acceptable, chain is near straight in middle cog and 38t ring and still vibrates

A couple of searches resulted in a new drive train vibration caused by mismatched brands of components. Could the Sram chain not mate well with the Blackspire rings?
 

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More info... Does it matter what chainring and cog you're in? Only certain combos?

If the vibration occurs at the same spot in every rotation of the crank no matter what gear you're in, then the issue probably isn't related to the chain, chainrings, cassette, or RD. Check your pedals and bb.
 
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