I was attempting to tighten the bearings in my Shimano PD-M530 pedals. I've done this procedure several times before on my other pedals, and I've never had issues before (M737 and M980). For some reason, the drive side (right) pedal's bearing adjustment ended up being reverse threaded, and I stripped the threads on the locknut trying to remove it. The other pedals I've adjusted (see list above) all had regular threading on both the left and right pedals. Similarly, all the online guides describing SPD pedal service I’ve read or watched say that bearing adjustment is normal threaded.

What other models of pedals are reverse threaded on the bearing adjustment? I don't want to destroy a perfectly good (and expensive) set of pedals again.

  • No idea, but in hindsight, can you see any marks on that pedal indicating a LH thread ?
    – Criggie
    Sep 13, 2020 at 19:36
  • 1
    @Criggie There was indeed a dab of blue paint on the nut. I thought it was just a manufacturing thing. The usual marks indicating a special thread (such as little cuts on the nut or an L) weren't present.
    – MaplePanda
    Sep 13, 2020 at 19:50

2 Answers 2


I found the answer in this document: https://si.shimano.com/pdfs/dm/DM-PD0002-07-ENG.pdf#page27


  • Right-hand thread: Black-colored (without slit) If the fitted lock nut is black-colored (without slit), the cone and the lock nut have a right-hand thread.
  • Left-hand thread: Black-colored (with slit) Silver-colored If the fitted lock nut is silver-colored or black-colored (with slit), the cone and the lock nut have a left-hand thread.”

I pulled both pedals apart again, and lo and behold, the left pedal’s locknut is a brown color, while the right pedal’s is plain silver.


Shimano flat pedals, PD-M8140 (XT), definitely have left hand threading on the right pedal. This includes the lock bushing threads as well as the cone and lock nut on the right spindle.

A look-up of the above model on Shimano's technical website will yield a result for a Dealer's Manual for this pedal which describes the procedure for adjusting the cone and lock nut assembly. It is here where the differing threading of the left and right pedals is described. There are two other models of flat pedals covered by this Dealer Manual, however, they use a bushing system rather than loose ball bearings. The end cap nut they use appears to be right hand thread for both left and right pedals.

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