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I need new chainrings due to slipping chain and decided to replace them. I currently have an Ultegra R8000 Chainset and don't want to replace the crank arms (as it is really expensive). Ultegra is almost 50% more expensive for the rings. Will the Shimano 105 R7000 chainrings fit this crank as I have heard different opinions on this and wanted to get some certainty from someone? Many thanks

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    The issue is that R7000, R8000 and R9000 cranks all have different 'three dimensional' profiles to the crank spider arms which is continued into the chainrings. Different series rings and cranks definitely do not match, and it is unclear if there is clearance issues which would prevent rings from one series being installed on a different series crank.
    – Argenti Apparatus
    Jul 29, 2020 at 17:41
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    How many miles on the chain rings? Are you certain it's the rings that need replacing rather than the chain? I ask because I will go through many chains before a chain ring ever needs replacement and I typically average 6k miles or more from a chain. The cassette, chain ring, and chain all wear at different rates but they will "bed-in" together, so you may still have to sort some shifting issues after replacing the rings.
    – jc allen
    Oct 6, 2020 at 18:20
  • You have an option to use aftermarket rings such as the TA X110 rings with the aesthetically pleasing bolts. The lower series rings will bolt on but there will be exposed "sharp" edges in some places where the ring/spider meet.
    – Noise
    Oct 11, 2020 at 21:26
  • What’s the durability like between the 105 and Ultegra rings? It may be better to buy the nicer ones if they’re more durable.
    – MaplePanda
    Oct 24, 2020 at 23:30

1 Answer 1

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Yes, they are 100% compatible. See https://si.shimano.com/api/publish/storage/pdf/en/ev/FC-R7000/EV-FC-R7000-4331A.pdf https://www.bike24.com/p2284436.html

R7000 & R8000 chainrings are a 'B' match, that is different materials but compatible.

With a 50/34 compact, then the rings are 'MS' pattern. Previous generation are 'MA', which is incompatible.

There is a high chance you can use the even cheaper/heavier RS510 chainrings, which are also 'MS', however I haven't seen that confirmed.

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  • I have an ultegra R8000 crank and wanted to install 105er R7000 chain rings. It is technically compatible, but the 3d shape doesn't fit. So it works, but it looks silly, since the 3d shape has a 2mm step between the crank and the chain ring. For me that's a no-go. So I had to order the FC-R8000 Chain ring, which is roughly double the price.
    – haferblues
    Jul 30 at 10:41

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