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I just read this article https://www.tikesbikes.com/pages/coaster-brake-vs-hand-brake and it confuses me. They oppose coaster brakes with free wheels. My understanding is that the opposite of freewheel is fixed gear and that the definition of freewheel is that you can roll the rear wheel while the pedals are at rest (not rotating). That is, most normal bikes with coaster brakes also have a freewheel setup.

Am I misunderstanding something here? And is there a word for bikes/the setup that allows you to pedal backwards?

Update: of course there is a Wikipedia article https://en.wikipedia.org/wiki/Freewheel and by just reading the introduction it seems that I am right. Freewheel has nothing to do with pedaling backwards. But that question remains: what's the word for a pedaling backwards setup?

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    If you want to be seriously confused, look up freecoaster and how it differs from freewheel. – ojs Jun 18 at 15:35
  • @ojs Do you have a link? – d-b Jun 18 at 23:20
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    The confusion comes from the use of Freewheel (noun) meaning a hub build in a way that allows back pedaling and "freewheel" (verb) for rolling forward without the pedals turning. In context of the verb form, you can freewheel using a coaster hub as long as you coast and do not pedal backwards and you can coast on a freewheel hub... and in the verb form coast and freewheel are synonyms, but not the noun form ....now you got me confused.... – mattnz Jun 19 at 4:35
  • @d-b lmgtfy.com/?q=Freecoaster – ojs Jun 19 at 5:35
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It doesn't make much sense to insist on one thing being the opposite of another, so let's just focus on what these things are, and you can decide for yourself what, if anything, is "opposite" of what.

  • A fixed-gear bicycle is one in which the rear sprocket is mounted rigidly to the rear wheel, so they can only rotate at the same speed as each other.

  • A freewheel is a mechanism that allows the rear sprocket (or sprockets) to freely rotate more slowly (fewer revolutions per minute) than the wheel, including rotating backwards while the rear wheel is stationary or moving forwards.

  • A coaster brake is a mechanism where pedalling backwards engages a brake within the hub.

I'm not sure what you mean by "Freewheel has nothing to do with pedaling backwards." The freewheel is precisely the mechanism that allows you to pedal backwards without either driving the bike backwards (as would happen on a fixed-gear bike) or braking (as would happen with a coaster brake).

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    No, the freewheel is what allows you to keep the pedals still when rolling downhill. I guess the first bikes where "fixies" which was a nuisance for people and caused accidents. – d-b Jun 18 at 13:09
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    @d-b That's just an example of the sprocket turning slower (zero rpm) than the wheel (some positive number of rpm), exactly as I said. – David Richerby Jun 18 at 13:33
  • Look at the article linked in the updated question. The two "wheel" involved (the actual rear wheel and the whole pedal arrangement) are not created equal. The pedals power the rear wheel, while the freewheel prevents the rear wheel from powering the pedals. – d-b Jun 18 at 23:23
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    @d-b You're saying exactly the same thing as me, but using different words. "The freewheel prevents the rear wheel from powering the pedals" means that the freewheel allows the pedals (and, hence, the sprocket on the rear wheel) to rotate slower than the rear wheel. – David Richerby Jun 18 at 23:25
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    @d-b I think this statement from the wiki page confuses you "The condition of a driven shaft spinning faster than its driveshaft exists in most bicycles when the rider stops pedaling." It doesn't say it's the ONLY condition. Also when pedalling backwards or at a lower rpm than the rear wheel the condition of a driven shaft spinning faster than its driveshaft exists. – Robert Lee Jun 19 at 2:19
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You are right, coaster brake hubs do employ the same mechanism as free-wheel hubs. The difference is, that the coaster brake limits the backwards movement of your pedals, which the pure free-wheel does not:

  • Fixie:
    Pedals have a fixed connection to the wheel, so they always move with the bike.
    Back-pedaling is not possible.

  • Coaster brake:
    Bike can coast along without pedals moving.
    Back-pedaling engages the brake.

  • Free-wheel:
    Pedals have full freedom to turn backwards with respect to the rear wheel.
    Back-pedaling is without effect.

  • Nit-pick: coaster brake hubs very rarely have the same mechanism as freewheels, i.e. ratchet pawls, they have a different means to allow coasting, using a clutch. – whatsisname Jun 20 at 5:54
  • @whatsisname My IGH with coaster brake does make the same tell-tale tick-tick-tick sound when coasting as a freewheel. And it does have the same tell-tale fixed engagement points. There's an additional mechanism for engaging the brake, but as far as I can tell, the coasting is made possible via a ratchet pawl. I may be wrong, of course, as I don't have the habit of taking my IGH apart, so I don't really know what's inside... – cmaster Jun 20 at 19:45
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Well with free wheel you can also roll while you are turning your pedals backwards, while on the coaster brake if you turn the pedals back you start to brake.

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I'll try to comment your statements and provide some clarification:

They oppose coaster brakes with free wheels.

In the article they compare two alternative braking mechanisms.

My understanding is that the opposite of freewheel is fixed gear

A freewheel and a fixed gear are indeed two different mechanisms, but it's hard to precisely define them as being opposite. In the article, because a fixed gear is not a very efficient braking mechanism, they don't consider it as a good alternative to hand brake.

the definition of freewheel is that you can roll the rear wheel while the pedals are at rest (not rotating).

This may not be the complete definition of a freewheel. You can do that with a freewheel, indeed. But also with a coaster brake. Some people use "coasting" and "freewheeling" interchangeably when referring to this functionality. But the mechanism in a coaster brake that allows your pedals to stay at rest is different than the one in a freewheel. This video explains how a coaster brake works:

That is, most normal bikes with coaster brakes also have a freewheel setup.

Coaster brakes can "freewheel" in the sense of allowing the pedals to stay at rest, but they don't require a ratcheting freewheel mechanism like the one in a bicycle freewheel.

what's the word for a pedaling backwards setup?

In a freewheel there's no additional mechanism for allowing you to pedal backwards, it's just that the pawls only engage in one direction, the same mechanism that allows coasting/frewheeling. So a ratcheting mechanism may be considered a pedaling backwards setup.

Edit: Or you may be confused whether or not pedalling backwards is also a functionality of the general freewheel term. Yes it is. It fits into the definition of a driven shaft spinning faster than a drive shaft. For example pedalling backwards at 60 RPM while the bike is standing still: driven shaft (rear wheel) 0 RPM > drive shaft (pedals) -60 RPM.

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