I'm looking for replacement pulley wheels for my RD-6401. It needs to have 10 teeth and a thickness of about 7.2mm.

I do have a set of Shimano 10 teeth pulley wheels in front of me (Y56398030) which don't fit because they are about 9mm thick (plus they are of poor quality).

Are there still replacements parts available?

  • For reference, 6400 and 6401 are the model numbers for 8-speed Ultegra.
    – Weiwen Ng
    Commented Oct 12, 2020 at 13:35

1 Answer 1


There are third party replacement pulleys available from at least BBB brand. They come with a set of adapters for different derailleurs, and in my opinion are better quality than low to mid tier original pulleys. There is also good chance that searching for the original spare part code finds a mail order shop that has the original part.

  • couldn't find any pulley wheels on the Tacx website, but found some on BBB's. Just sent them an email asking which one fits on a 6400.
    – user430
    Commented Oct 12, 2020 at 14:31
  • Interesting, looks like Tacx recently stopped selling them, so that there are still some final sales available. I'm updating the answer.
    – ojs
    Commented Oct 12, 2020 at 14:35
  • Strange, I bought some last year, Perhaps time to buy some last pieces as a backup. Commented Oct 12, 2020 at 15:07
  • It's probably the tacx t400 I needed. But tacx now belongs to Garmin, they don't even have an email address anymore for contacting them.
    – user430
    Commented Oct 12, 2020 at 16:02
  • Looks like Garmin axed the pulleys department or something similar. Commented Oct 13, 2020 at 8:57

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