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There is "coaster brake" mechanism, it consists of not only brake, but also of freewheel. As can be seen in answers in Why there are no or few bicycles with coaster brake and external speed gears? , coaster brake is incompatible with derailleur, because it "requires significant tension on the lower part of the chain when it is applied" while derailleur requires that the lower part of chain is relaxed. The lower part of the chain is tensioned only when pedal is pressed in direction opposite to usual ie, when the brake is pressed. (The usual direction is when pedal tries to accelerate bicycle forward.) So, seems, the problem appears only when the brake is applied. So, brake component of the "coaster brake" is incompatible with derailleur. (This means that pedal brake cannot be installed together with derailleur.) But what about the freewheel component of the "coaster brake"? Can such freewheel mechanism be used on the same wheel together with derailleur? I think it would be a viable thing, because it is noiseless. "Freehub" freewheel mechanism, which uses ratchet, is used nowadays with derailleur, and ratchet produces trilling noise while coasting.

I have seen a video of how coaster brake works,

. I feel from the video that the freewheel component of the "coaster brake" can be engineered and produced without the brake component.

Seems, derailleur is most popular gear change mechanism, nowadays. "Coaster brake" is also a popular mechanism, and seems it was relatively even more popular in the past. As I see, despite they both are so popular, the freewheel of "coaster brake" is not adopted for usage with derailleur for some reason, I have never seen such combination of bicycle components. Maybe somebody has tried, thinked about it, but found it impossible?

qdinar
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  • Please post a second question about the noise/silence of hubs. It's a mix of technology and fashion, and very separate from the question that the existing answerers have put effort into addressing. – RLH Aug 25 '22 at 20:39
  • @RLH almost at same time you commented, i added: " Excluding so called "coaster brake" as a whole is OK, thank you, but it is not full answer. " , so, i think, the answers are not totally useless... so, you want to have question about diralleurs and coaster brake, and your answers would be totally ok then... – qdinar Aug 25 '22 at 20:47
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    Criggie and I have both answered the question of "why not have a derailleur with a coaster brake". Best practice for Stack Exchange etiquette would be to narrow down this question to that subject, and then ask a new question about the noise made by mechanisms while coasting. – RLH Aug 25 '22 at 20:51
  • @RLH i made mistake with title but content was ok. why you answered only to the title? probably you should not. i do not feel myself so much guilty, to edit the question to match your answers. i would like more to create a new question about coaster brake and derailleur, or you create it. – qdinar Aug 25 '22 at 20:54
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    Your question had multiple components, and the presumption here is that the title provides the most accurate summary of what you had in mind when you asked the question. (Note that two experienced users both interpreted your question the same way). The answers also address the objective technical question from the original post, rather than the subjective fashion question. There's no reason to feel guilty about editing down a multipart question to match the part that other users answered. – RLH Aug 25 '22 at 21:00
  • @RLH you should read content. title was also ok. because so called coaster brake has 2 components in it. i was not interested in the brake part of it. i just called it as it is called, as a popular combination of mechanisms... explanation was in the content part. – qdinar Aug 25 '22 at 21:07
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    I'm not going to argue with you any more. You asked a question titled about coaster brake hubs, with a video about coaster hubs, and two experienced users took the time to answer you about coaster hubs. You've clarified what your actual interest is, and (to help out because you're new here), I've suggested how to proceed in accordance with the site norms. You've responded to this courtesy by insulting my reading skills. – RLH Aug 25 '22 at 21:13
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    @qdinar welcome to the site. You have the cross-site rep bonus, so clearly you know how SE works. These comments are not antagonistic, they're working to improve and clarify the question. If your intent is to ask about quiet freehubs, then why mention coaster brakes at all? – Criggie Aug 25 '22 at 22:27
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    Possible duplicate of https://bicycles.stackexchange.com/questions/14194/is-there-such-thing-as-a-freewheel-that-doesnt-click/ and https://bicycles.stackexchange.com/questions/40486/what-road-hub-makes-the-least-amount-of-noise/ and https://bicycles.stackexchange.com/questions/4606/what-causes-the-noise-that-race-wheels-make-when-you-are-not-pedaling/ and https://bicycles.stackexchange.com/questions/15321/why-are-higher-end-freewheels-so-much-louder-when-coasting/ and many entries in https://bicycles.stackexchange.com/search?q=quiet+freehub or at least relevant. – Criggie Aug 25 '22 at 22:28
  • @Criggie when i started to write, i did not know that brake part and rotation part are separable mechanisms. i have known this out from the linked video which i have found out just then. and i am still not very sure. then i edited the post many times, in text editor, before pasting into browser and submitting, but forgot/failed to recheck the title with more/enough attention. why i mentioned them - because i think these are names of concrete mechanisms, "freehub" cannot be quite because it includes ratchets, "coaster brake" includes something useful for me. – qdinar Aug 25 '22 at 23:26
  • @Criggie this is not duplicate of the 14194 question, because it asks is there such thing at all, but i already know that there is a such thing, and i ask, why it is not popular. – qdinar Aug 25 '22 at 23:47
  • i do not know english and bicyce terminology well, and had not correctly learned what is freewheel and freehub. i have found out now that they are not only made with ratchet. i did not read wikipedia text with attention, and the illustrations were what i remembered, wrongly. – qdinar Aug 26 '22 at 06:41
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    If the question really "why aren't silent freewheels popular", why is there a wall of text about coaster brakes, Soviet Russia and other unrelated things? – ojs Aug 26 '22 at 06:58
  • @ojs stackexchange does not allow short questions, so i tend write some background of the question if i can. this also makes question more funny, less boring. russia, because i live in russia, i did not know what is in other places. but for now, i have seen in a video that it was similarly in many other countries, coaster brakes were more popular. – qdinar Aug 26 '22 at 07:24
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    question has minus 3 votes. as i know, it is going to be unpublished. i am going to make new questions. it would be hard to edit this question, and if i edit, comments would become outdated. and it would be hard to regain votes. – qdinar Aug 26 '22 at 07:31
  • i have made 2 new questions, but could submit only one of them. it was marked as duplicate of this and has -1 votes. this has -4 votes. i could not post the second of them because of low quality of previous qustions. then, i have posted content of the second question here, as a complete rewrite. – qdinar Sep 04 '22 at 19:21

1 Answers1

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Coaster brakes won’t work with external (i.e. derailleur) gearing.

Coaster brakes require the bottom section of the chain to be in tension (to pull against the brake assembly). Derailleurs need the bottom section of the chain to be effectively slack (so that the derailleur can move to take up extra chain length when in smaller-radius gears).

RLH
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