CyclingTips: "An ode to the Shimano PD-M520, the world’s most reliable pedal"

[jtbadge]

"Cyclists can be a fickle bunch, preoccupied with the latest flashy advances. But while marquee products get all the attention and column inches, that’s not what most people are riding. It’s the workhorses of a brand’s product line-up that are out there in multitudes, not because they’re the best and the most expensive but because they’re perfectly fine and the right price."

The PD-M520 is really a perfect product in my estimation. Affordable, dead reliable, and built for the long haul. I'm glad I bought a set of these with my first nice bike - and I'm still running the same set to this day, never needing a bit of maintenance.

https://cdn-cyclingtips.pressidium.com/wp-content/uploads/2020/07/IMG_3336.jpg

[Mark McM]

The article failed to note another apparent improvement in this SPD design iteration: In the first iteration of the SPD pedal, as the cleat wore, it became harder and harder to release from the pedal, until finally it wouldn't release at all. I know of several people who were unable to release from these earlier pedals, and in fact one MTB World Champion (Carol Waters, 1995 Veterans Cross Country World Champion) injured her leg badly enough in a fall where the cleat wouldn't release that she missed the entire next racing season (and therefore never was able to race in the World Champion rainbow stripes).

[dddd]

Maybe it's just me(?), but I find that certain bearing issues crop up with the DEORE-level PD-M520 pedals within relatively short periods of first use.

Firstly, with the plastic spline nut holding the tubular unified outer race under needed compression for slop-free positioning of the axle, there is the inevitable loss of compression due to the plastic yielding it's rigidity.

From this point forward, the axle is now wobbling within the seal and within the plastic nut that retains the seal. This goes on for a while until the plastic and aluminum surfaces compressing the ends of the tubular unified race wear away. At this point, tightening the nut has no effect as it is already bottomed out on the end surface of the "snout" of the pedal body.

If the above is addressed before the now-malfunctioning seal allows too much contamination to reach the bearings, the pedal can still be saved with some considerable amount of effort as follows:

The spindle cartridge is withdrawn, and the end surface of the pedal body snout filed down to prevent the nut bottoming out before actually compressing the tubular unified outer race.
The bearings by now will benefit from some degree of tightening, as these pedal's tiny bearings wear rapidly. So amidst what looks like already contaminated grease we adjust the bearings with a tiny 6mm box-end wrench and a thin 10mm box-end wrench. This is a messy job here, so I wait till I have three pairs waiting for the same service to spare redundant cleanup of hands and tools. It's all just a bit too common on an ubiquitous, inexpensive model of pedal that seems just too good to throw away.

Other than that, I think that the M520 pedals are the best considering their low cost.

Stepping up to the PD-M540, model which is functionally identical, the bearing situation is much, much better in every way, a difference that I could measure in years.

So it's kind of a love/hate thing with the PD-M520, a great OEM ~disposable item that needs/deserves some messy attention once in a while because it's just too good to throw away!


BTW, the exact same situation exists with Shimano's Tiagra-level PD-R540/R550 pedals in aluminum and in "carbon" respectively, with the higher-tier "R7000" 105 model being the cure here for same bearing issues.

[AngryScientist]

i'm a pretty die-hard campy guy but concede that shimano makes the best pedals out there, road and mountain.

i cant say enough good things about S pedals. they just work and dont need any attention. they are one of those components i trust 100% and dont even think about.

[AllesWirdGut]

I think Shimano does make the most durable and reliable pedals, but for me it's been the XT-level PD-M8000. I've had them on all my bikes for years and year, not a single issue, scarcely even a drop of oil.