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My XT FC-M782 40T chainring (Shimano code Y1NV98020) has worn out. My favorite bike shops don't stock them any more. Instead, FC-MT500 40T (Y1VB98020 or Y1VB98030) are available. Shimano does not state them to be cross compatible.

I suspect that they actually have identical hyperglide shape as they have the same "hyperglide code" 40T-AN and thus the difference in shifting would be minimal, if any. Does someone have real-life experience mixing these two, or maybe both chainrings at hand to confirm or confront this?

(I'm aware of other ways to upgrade or downgrade this old 10-speed transmission, but now I'm asking only about compatibility of the named chainrings.)

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2 Answers 2

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FC-M782 is XT series. FC-MT500 is SLX series, the next drivetrain down from XT (XTR, XT, SLX, Deore)

Hyperglide is Shimanos label for the general technology of up and down shifting ramps and pins machined or pressed into the rings (and cassette). Everything in the MT series down to at least Deore has that same technology. The only difference you are likely to notice will be subjective.

The existing chainring and FC-MT500 have the same slightly odd shaped bolt arms. You can replace one with the other on the Shimano cranks.

When you replace attempt to get the ring clocked in correctly. Only one positions in four will be correct for shifting well. There may be a register mark on the ring to assist.

FC-MT782

FC-MT782

FC-M500

FC-M500

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    Odd shaped but not proprietry. It's an optical illusion. The rings still fit around an imaginary circle at the spider, there are no funny protrusions even though it looks like there are
    – Noise
    Commented Oct 27 at 17:06
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    They aren’t “universal”. I had to attack one of this design with a grinder to get it to fit on a regular FSA/SRAM crank. Only a couple of mm but annoying.
    – Warren Burton
    Commented Oct 27 at 17:59
  • I suppose that I'm thinking about it from the other side: The design of the spider doesn't stop you using another manufacturer's rings.
    – Noise
    Commented Oct 27 at 18:11
  • @WarrenBurton you put the labels the other way around, the first linked chainring is from FC-M782, the second one from FC-MT500. Apart from that, I know that they fit on the same spider; my question is whether they are "hyperglide-compatible".
    – Konstantin Shemyak
    Commented Oct 28 at 9:51
  • They appear to be symmetrical, so two of four positions should work. Of course, the chain retention pin to be placed under the crank arm will key the correct set up.
    – Dan Gao
    Commented Nov 18 at 16:00
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The more basic chainrings you specify will be a fit. It looks to me like they are stamped steel rather than the aluminium you are used to with XT.

You will probably find shifting is not quite so good as the shapes are less complex and chainring life may not be as good depending how hard the steel is: they are not expensive rings. Obviously will be heavier too, and show cosmetic corrosion after life in harsh conditions.

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  • FC-MT500 40T chainring is aluminium.
    – Konstantin Shemyak
    Commented Oct 27 at 9:29
  • Any of them will fit, do what you want. @KonstantinShemyak
    – Noise
    Commented Oct 27 at 11:10
  • I would swear M782 is steel, from the photos. When you compare Warren's photos, you can see the teeth align the same way with the drop prevention pin, so the shift timing is the same. Materially, the cheaper rings are inferior and the machining is less, less time is spent on them. It is obvious that the M782 is stamped in a single process with some pins added. The SLX has some machining performed to enhance shift. @KonstantinShemyak
    – Noise
    Commented Oct 27 at 17:04

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