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I’m shopping for some pedals for a couple of our bikes (folding bikes/folding pedals although not necessarily germane to my question) and noticed a number of available pedals, mostly on Amazon, but elsewhere, that claim to feature “polymer bearings” versus ball or sealed ball bearings which I am familiar with having rebuilt numerous pedals over my riding career.

Does anyone here have any info, firsthand experience, warnings, blessings and/or insights on pedals equipped with polymer bearings?

Thank You and please share!

JohnDThompson 

I'm not familiar with that term being used in the context of pedals, but if these are low-end pedals, it may refer to a plastic sleeve-type bearing/bushing rather than balls in a race.

HillRider

"Polymer bearings" are just another way of saying plastic bushings. I expect the durability would be very poor if used for serious riding. These things are made to be cheap and for very casual, low milage riding.

Gresp15C

In my view everything would depend on the original finish of the materials, and the quality of the seals. Polymer sleeve bearings are in industrial use, and can last a long time when used as intended. (How's that for weasel words). But let just one grain of grit get in there, and you're toast. Among their other attractions, ball bearings can usually sling the grit away well enough to survive minor incursions.

jccaclimber

As above, plastic sleeve on a steel shaft, typically some grease in between.
I was recently surprised to discover just that on the off brand SPD pedals on one of my wife's bike-. I suspect they only have a couple thousand miles on them at most (and are about a decade old, that bike isn't ridden much), but they looked brand new inside when I opened them. May well cost a watt or two, but she hasn't noticed yet and under hand loading they feel not that different from the 3 bearings in my X0's.

Iride01 

If you were trying to sell a cheap to build pedal and sell it, where would you do that? On a site with a few hundred hits a day or a site with a ba-zillion hits a day?

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Thanks for the input.

Upon further research I'm not convinced polymer bearings are a trademark of "cheap" pedals, but an (and possibly an up-and-coming) alternative to old school balls and cups, grease and maintenance....similar perhaps to the evolution of CF bicycle frames vs aluminum or steel. Time will tell. Electric automobiles vs fossil fueled ones etc. You get the point.

That said, if I purchase and install this type of pedal I will provide real-world feedback and that provided by jccaclimber up-thread is interesting and thought-provoking for me as does this:
https://blog.igus.eu/plain-bearings-...es-of-polymer/

Bigbus

My latest pedals that I purchased for my MTB that I no longer have but do have the pedals on my old Giant RB now because I like them so much are Rock Bros 4 bearing platforms. They basically have 4 'polymer sleeve bearings' and after a lot of abuse and use are still as smooth as a baby's butt and are still my favorite pedal. They can be taken apart and serviced just like regular old steel ball bearing, but when your bike is in mud and water a lot they will never rust. The sleeves do have rubber seals on the ends and a preload requirement just like ball bearings. They are not LOW END pedals just because they have 'polymer bearings'

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I happened to notice this evening that our e-bikes both have Wellgo folding pedals on them, which have never provided me as much as a second thought. I looked on Wellgo.com and they have an entire, extensive range of polymer-bearing-ed pedals, including the ones I mentioned previously. Our e-bikes have over 2000 miles (nearly 2500) each, and the pedals all spin freely and smoothly. Color me impressed....I've rebuilt several BB pedals over time, and almost always have had to adjust new BB pedals from the box, for proper tension and smoothness. In my mind these poly bearings are now "a thing", theyve required zero attention from me and still spin freely and smoothly...exactly what a pedal is meant to do.

rccardr 

There are several kinds of polymer bearings- some are like regular sealed style bearings but with polymer races and stainless steel balls, caged or uncaged. Others are more like plastic sleeves or bushings.
There are a couple advantages to them, including the ability to precisely engineer the polymer for the application (e.g. high load, radial load, temperature, rpm) and for the polymer to self lubricate.
Pretty cool stuff,, not necessarily indicative of a cheap pedal. But would make even a cheap pedal a better performer.

Mad Honk 

My first thought went to the Ceramic bearings offered for pedals. But at the initial cost of $15 per bearing; the whole lot needed is astronomical for the convenience of never having to rebuild or lubricate the pedals. I suspect the cost per ball has gone down a bit over the last year but still a very pricey upgrade. I am glad this is not what they were referring to. Smiles, MH

Dan Burkhart 

Pedals with bushing type bearings are nothing new Raleigh had them back in the late 60s early 70s.
The main issue is that the pedal eye threading direction is designed to counter the precession of ball bearings. This force is not present in a bushing type, so from a technical point of view, the threading should be reversed.

jccaclimber

The issue is the rolling between the spindle threads and the crank due to pedaling forces. This is present in bearing and bushing designs.

Dan Burkhart 

Present yes, but reversed in the ball bearing type.

jccaclimber

What about bearings causes that reverse? Precession is driven by the radial forces, not rotational. With the system boundary drawn at the shaft to bearing/bushing contact, the shaft doesn't know what's touching it. It could be a ball, roller, loose sleeve, outer bushing (this case), etc.