10

I've noticed cheaper pedals (also the <5$ ones) spin forever if you give them a tap with your finger. My own pedals seem to have a little resistance in the bearing. You can turn them with no effort but they stop immediately.

I visited a bike shop and started flicking pedals on various mountain bikes (to the annoyance of the shop owner who must have thought I was fooling around) so I conclude this to be an actual thing for more expensive pedals. It also read on some case "The right amount of friction added to bearing".

So the question is WHY??

And if this really should be a good thing, how many watts can you lose with a pedal like that?

  • 1
    bicycles.stackexchange.com/questions/40905/… answers this question, although the question is perhaps slightly different – Móż Jan 29 '17 at 22:52
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    cyclingpowerlab.com/drivetrainefficiency.aspx suggests that "Cheap pedals with cheap bearings - technically a little higher up the power transfer chain than the drivetrain per-se - can also cost 1 watt." – Móż Jan 29 '17 at 23:47
  • +whatsisname you have no sense of humor ;-) – AzulShiva Jan 30 '17 at 9:15
  • There is also pluses and minuses to each dependent on type of cycling done, Dirt jumpers for example prefer a pedal that does not spin freely because once you take you foot off in the air it is harder to re-plant your foot if their spinning. – Nate W Jan 30 '17 at 15:56
18

There does seem to be an upside down U-curve of spinniness on pedals with the horizontal axis being price and the vertical axle being how many rotations it makes when spun by hand.

enter image description here

Cheap pedals are genuinely horrible. They just have a sleeve bearing, bushing, or single set of ball bearings. Tolerances are atrocious because they were made by drunken lemurs, who also lubed them using the grease that was at the bottom of the bilge pump of the last freighter into their god forsaken port.

Mid-grade pedals use a one or two sets of sealed cartridge ball bearings. These are cheap and easy to place. They might use a light grease and are low in unloaded friction, so this accounts for the spinniness of mid-grade pedals. You can't really maintain or adjust them.

High-grade Cartridge bearings are good for unloaded friction but are limited under load. They also can't be adjusted, maintained, or re-greased. Higher end pedals use a combination of adjustable cup-and-cone, needle (roller) bearings, and/or sometimes multiple/heavier duty cartridge bearings. Cup-and-cones are adjustable and maintainable, and avoiding cartridge bearings saves weight because you don't need the bearing retainer -- also cup-and-cones can feel heavier than cartridges when unloaded but lighten under pressure. Needle-bearings can support MUCH more weight than ball-bearings. Grease intended for heavier duty seems thicker under low-load but lightens up when loaded. Finally, because higher-end pedals are lighter, they have less inertia when spinning by hand and so will stop spinning sooner just for that fact alone. In summary, high-end gear might not spin as much unloaded, but they can be lighter, stronger, more adjustable, maintainable, and smoother under load. Note: Some of these properties are mutually incompatible.

tl;dr: You can't tell anything by freespinning a pedal by hand except for the crappiest of pedals. For almost all bicyclists, just get a mid-range pedal. You don't put enough power/weight through the pedals or go long enough distances to make a difference. For pros, you are pumping so many hundreds of watts through the pedal over longer distances, so you want a pedal that can take that power and transmit it properly.

Also note that older midgrade pedals in the era before cheap cartridge bearings often used cup and cone bearings. These can often be tuned up quite nicely.


This is the Shimano PD-R9100, their highest end pedal. It uses two sets of adjustable bearing groups. It's designed to be as light and strong as possible but can also be fully adjusted and maintained.

Shimano PD-R9100

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  • 1
    Maybe they've become less common in the last few years, but there were also some quite cheap (bottom end of mid-range?) pedals with unsealed/loose ball bearings at both ends and limited adjustment. I cleaned out and repacked a set when I relegated them to a beater bike. I'm sure there are other permuations as well, but this answer sums up the range and (lack of) conclusions you can draw from a hand-test. – Chris H Jan 30 '17 at 11:39
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    Thanks Chris. I added a note about older pedals with cups and cones. – RoboKaren Jan 30 '17 at 17:50
7

The difference is in the lubricant. Ball bearings need to be lubricated with a sort of grease. This grease is in your wheel hubs and also in your pedal bearings. The grease is gooey. Gooeyness means that some very small amount of energy is consumed as the stuff moves around.

You don't notice this energy loss on a wheel because wheels have a lot of momentum, so that overrides the tiny amount of energy lost in the grease. But pedals are often incredibly light, and, lacking much momentum, it does not take much drag from the grease to make them stop spinning. The lighter the pedal (and good quality pedals tend to be lighter), the greater the effect -- the pedal slows down from spinning faster.

There is also the point that better quality pedals contain bearings with closer tolerances, and the lubricant effect is stronger with tighter tolerances. (And, truth be told, some cheap pedals are not lubricated from the factory, other than perhaps a squirt of oil.)

But lest one be concerned about this minuscule energy loss, know that, as you pedal, the grease warms up and softens up significantly, reducing the loss even further.

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  • There is something to be said for those riding in significant cold. Pedals should be winterized as well for those of us riding in subzero weather. Pedals with thick grease will rob some power in sub arctic conditions. Along with everything else, it can become significant. – Deleted User Jan 30 '17 at 21:32
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    That's finally a reason to use my favourite engineering term: Sticktion [sic!]. Which is a neologistic homonym of the engineering term stiction, a portmanteau of static friction. Sticktion is the stiction caused by sticky lubricants in bearings (which gave Nasa momentum wheel engineers quite a lot of trouble). – gschenk Jan 31 '17 at 0:05

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