BuildMyMTB
Prototype - Evolving Daily

Campagnolo Ekar RD Rear Derailleur

What the checker says50will not fit

Run variant by variant through the gravel bike builder’s own engine. Every sentence below is the checker’s, unedited. Nothing here says this part fits your bike; it says what it does and does not fit among the parts we hold.

Checked against 861 verified gravel bike parts in this catalog. 805 produced no finding of any kind.

Will not fit

  • Will not fiterror · CassetteSpeed mismatch: Rear derailleur 13s, Cassette 12s. The drivetrain must share one speed count. On 8 of the 18 verified cassettes in this catalog.
  • Will not fiterror · Shifter/Brake LeversSpeed mismatch: Shifter 12s, Rear derailleur 13s. The drivetrain must share one speed count. On 5 of the 17 verified shifter/brake levers in this catalog.
  • Will not fiterror · CassetteDrivetrain mismatch: Rear derailleur = campag-ekar-13, Cassette = shimano-grx-12. Shifter, derailleurs and cassette must be one system. On 4 of the 18 verified cassettes in this catalog.
  • Will not fiterror · Front DerailleurDrivetrain mismatch: Front derailleur = sram-axs-road, Rear derailleur = campag-ekar-13. Shifter, derailleurs and cassette must be one system. On 4 of the 11 verified front derailleurs in this catalog.
  • Will not fiterror · Shifter/Brake LeversDrivetrain mismatch: Shifter = shimano-grx-12, Rear derailleur = campag-ekar-13. Shifter, derailleurs and cassette must be one system. On 4 of the 17 verified shifter/brake levers in this catalog.

Rg chain std, Chain. 15 more findings from the same check, on up to 1 of the 17 verified chains each.

Rg actuation, Shifter/Brake Levers. 7 more findings from the same check, on up to 1 of the 17 verified shifter/brake levers each.

Rg drivetrain system, Cassette. 6 more findings from the same check, on up to 3 of the 18 verified cassettes each.

Rg drivetrain system, Shifter/Brake Levers. 6 more findings from the same check, on up to 3 of the 17 verified shifter/brake levers each.

Rg drivetrain system, Front Derailleur. 4 more findings from the same check, on up to 3 of the 11 verified front derailleurs each.

Rg rd capacity, Cassette. 3 more findings from the same check, on up to 2 of the 18 verified cassettes each.

Rg drivetrain speeds, Cassette. 2 more findings from the same check, on up to 3 of the 18 verified cassettes each.

Rg drivetrain speeds, Shifter/Brake Levers. 2 more findings from the same check, on up to 3 of the 17 verified shifter/brake levers each.

Open a variant in the builder to see the ones that apply to your own parts.

The checker compares the dimensions listed in what we check, and what we don’t. “No conflicts found” means no conflict among those dimensions — not a guarantee that a build works. Errors mean it won’t fit; warnings mean it works but check; infos are notes.

$380.00 MSRP·275 g

What the maker states

System
Drivetrain system campag-ekar-13
Speeds
13-speed (rear index count the maker rates it for)
Actuation
Mechanical
Maximum cog
Largest cog 44 teeth
Mount
Std-hanger
Cage
gs cage
The rest of what the maker states2 not published

2 further fields the checker looks for are not published by Campagnolo, so we leave them blank rather than estimate them, and those 2 checks stay silent on this rear derailleur. They are maximum cog top and total capacity. Each is recorded as “not stated by the maker (not checked)”.

Source: the maker’s page. Last checked 2026-07-20.

Checked against

The checker ran this model against every verified part below that it has a slot for, the same way it checks a build in the builder. What follows is the verdict it actually produced for that specific pairing — not a recommendation, and not a guarantee any of these parts fits your own bike.

6 of 506 counterparts with a page of their own that the checker actually probed this model against, in alphabetical order by brand and model — never by price, popularity or the verdict itself.

Where this sits

Campagnolo Ekar RD is the first model on that list.Next: Campagnolo Ekar GT RDAll Campagnolo rear derailleursOpen a variant in the builder to see the ones that apply to your own parts