Chain suck sucks -- frame protectors

On 2/4/2021 3:05 PM, AMuzi wrote:
On 2/4/2021 11:23 AM, Tom Kunich wrote:
On Wednesday, February 3, 2021 at 7:51:14 PM UTC-8,
wrote:
On Wed, 3 Feb 2021 13:47:32 -0800 (PST), Tom Kunich
wrote:

On Wednesday, February 3, 2021 at 1:32:20 PM UTC-8,
wrote:
On Wed, 3 Feb 2021 11:10:58 -0800 (PST), Sir Ridesalot
wrote:

Isn't this the type of problem that the newer clutch-type rear
derailleurs were designed to stop?
Cheers
Yes.

The idea is to maintain the tension on the chain between the
chainwheel and rear derailleur. That should help prevent chain suck
if the chain is "glued" to the chainwheel by mud or crud. However, I
doubt it would provide sufficient tension to force the chain away from
a chainwheel that has hooked teeth. Also, notice that as the
chainwheel rotates past the point where the chain is expected to
release from the chainwheel, the holding force of a hooked tooth
increases. By the time the chain reaches the tail end of the front
derailleur, it's effectively locked in place by the hooked teeth. This
is probably why we don't see some kind of chain stripper attached to
the trailing end of the front derailleur. It would be really
difficult to provide enough rearward force on the chain to tear it
away from hooked teeth.

Full disclosu I've played with clutch type rear derailleurs on
other people's bicycles but have not tried one on mine. Not enough
experience with these to be certain that I haven't missed something.
Someone with more experience should be able to give a better answer.

I haven't seen that term used before. What is the difference between
the modern derailleur and the older type?
The difference between modern and older is one year or greater.
According to the dates on the relevant YouTube videos, the clutch
derailleurs started appearing about 4 years ago. I haven't been
paying attention and was informed that they exist a few weeks ago.

Google search finds a substantial number of articles on the topic,
along with a substantial number of opinions.
https://www.google.com/search?q=clutch+type+rear+derailleur
https://www.youtube.com/results?search_query=clutch+derailleur
I'm lacking in experience with clutch type rear derailleurs and
therefore can only refer you to the available articles and to suggest
you ask those with more experience.
--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
I wouldn't call that a clutch. I'd call it a derailleur arm ratchet
mechanism to maintain high pressure on the arm only in one direction.


I wouldn't either but Shimano does so it's a 'clutch'.

I wouldn't call clipless pedals "clipless pedals."

That misnomer arose because we called their predecessors "toe clips,"
which made no more sense. Those didn't clip. And clipless pedals do clip.

But what can you do?


--
- Frank Krygowski

On Thursday, February 4, 2021 at 1:24:15 PM UTC-8, Frank Krygowski wrote:
On 2/4/2021 3:05 PM, AMuzi wrote:
On 2/4/2021 11:23 AM, Tom Kunich wrote:
On Wednesday, February 3, 2021 at 7:51:14 PM UTC-8,
wrote:
On Wed, 3 Feb 2021 13:47:32 -0800 (PST), Tom Kunich
wrote:

On Wednesday, February 3, 2021 at 1:32:20 PM UTC-8,
wrote:
On Wed, 3 Feb 2021 11:10:58 -0800 (PST), Sir Ridesalot
wrote:

Isn't this the type of problem that the newer clutch-type rear
derailleurs were designed to stop?
Cheers
Yes.

The idea is to maintain the tension on the chain between the
chainwheel and rear derailleur. That should help prevent chain suck
if the chain is "glued" to the chainwheel by mud or crud. However, I
doubt it would provide sufficient tension to force the chain away from
a chainwheel that has hooked teeth. Also, notice that as the
chainwheel rotates past the point where the chain is expected to
release from the chainwheel, the holding force of a hooked tooth
increases. By the time the chain reaches the tail end of the front
derailleur, it's effectively locked in place by the hooked teeth. This
is probably why we don't see some kind of chain stripper attached to
the trailing end of the front derailleur. It would be really
difficult to provide enough rearward force on the chain to tear it
away from hooked teeth.

Full disclosu I've played with clutch type rear derailleurs on
other people's bicycles but have not tried one on mine. Not enough
experience with these to be certain that I haven't missed something..
Someone with more experience should be able to give a better answer..

I haven't seen that term used before. What is the difference between
the modern derailleur and the older type?
The difference between modern and older is one year or greater.
According to the dates on the relevant YouTube videos, the clutch
derailleurs started appearing about 4 years ago. I haven't been
paying attention and was informed that they exist a few weeks ago.

Google search finds a substantial number of articles on the topic,
along with a substantial number of opinions.
https://www.google.com/search?q=clutch+type+rear+derailleur
https://www.youtube.com/results?search_query=clutch+derailleur
I'm lacking in experience with clutch type rear derailleurs and
therefore can only refer you to the available articles and to suggest
you ask those with more experience.
--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
I wouldn't call that a clutch. I'd call it a derailleur arm ratchet
mechanism to maintain high pressure on the arm only in one direction.


I wouldn't either but Shimano does so it's a 'clutch'.
I wouldn't call clipless pedals "clipless pedals."

That misnomer arose because we called their predecessors "toe clips,"
which made no more sense. Those didn't clip. And clipless pedals do clip.

But what can you do?

Well, we can complain, and we can complain about "group set," or "frameset" too -- or crank(s) and axle/spindle, and whatever else Jobst used to complain about. And when did ten speed (cogs times chain rings) become ten speed (cogs only). I have a 22 speed! I want to complain about "tyres." It's "tires" -- just like wires, hires, and liars.

-- Jay Beattie

On Thursday, February 4, 2021 at 1:37:54 PM UTC-8, jbeattie wrote:
On Thursday, February 4, 2021 at 1:24:15 PM UTC-8, Frank Krygowski wrote:
On 2/4/2021 3:05 PM, AMuzi wrote:
On 2/4/2021 11:23 AM, Tom Kunich wrote:
On Wednesday, February 3, 2021 at 7:51:14 PM UTC-8,
wrote:
On Wed, 3 Feb 2021 13:47:32 -0800 (PST), Tom Kunich
wrote:

On Wednesday, February 3, 2021 at 1:32:20 PM UTC-8,
wrote:
On Wed, 3 Feb 2021 11:10:58 -0800 (PST), Sir Ridesalot
wrote:

Isn't this the type of problem that the newer clutch-type rear
derailleurs were designed to stop?
Cheers
Yes.

The idea is to maintain the tension on the chain between the
chainwheel and rear derailleur. That should help prevent chain suck
if the chain is "glued" to the chainwheel by mud or crud. However, I
doubt it would provide sufficient tension to force the chain away from
a chainwheel that has hooked teeth. Also, notice that as the
chainwheel rotates past the point where the chain is expected to
release from the chainwheel, the holding force of a hooked tooth
increases. By the time the chain reaches the tail end of the front
derailleur, it's effectively locked in place by the hooked teeth. This
is probably why we don't see some kind of chain stripper attached to
the trailing end of the front derailleur. It would be really
difficult to provide enough rearward force on the chain to tear it
away from hooked teeth.

Full disclosu I've played with clutch type rear derailleurs on
other people's bicycles but have not tried one on mine. Not enough
experience with these to be certain that I haven't missed something.
Someone with more experience should be able to give a better answer.

I haven't seen that term used before. What is the difference between
the modern derailleur and the older type?
The difference between modern and older is one year or greater.
According to the dates on the relevant YouTube videos, the clutch
derailleurs started appearing about 4 years ago. I haven't been
paying attention and was informed that they exist a few weeks ago.

Google search finds a substantial number of articles on the topic,
along with a substantial number of opinions.
https://www.google.com/search?q=clutch+type+rear+derailleur
https://www.youtube.com/results?search_query=clutch+derailleur
I'm lacking in experience with clutch type rear derailleurs and
therefore can only refer you to the available articles and to suggest
you ask those with more experience.
--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
I wouldn't call that a clutch. I'd call it a derailleur arm ratchet
mechanism to maintain high pressure on the arm only in one direction..


I wouldn't either but Shimano does so it's a 'clutch'.
I wouldn't call clipless pedals "clipless pedals."

That misnomer arose because we called their predecessors "toe clips,"
which made no more sense. Those didn't clip. And clipless pedals do clip.

But what can you do?
Well, we can complain, and we can complain about "group set," or "frameset" too -- or crank(s) and axle/spindle, and whatever else Jobst used to complain about. And when did ten speed (cogs times chain rings) become ten speed (cogs only). I have a 22 speed! I want to complain about "tyres." It's "tires" -- just like wires, hires, and liars.

Well, in my book a group is a group but a frameset is both frame and fork. I don't care if the English spell things differently. If they can drive on the wrong side of the road, misspelling things is the least of their problems.

On 2/4/2021 4:37 PM, jbeattie wrote:
On Thursday, February 4, 2021 at 1:24:15 PM UTC-8, Frank Krygowski wrote:
On 2/4/2021 3:05 PM, AMuzi wrote:
On 2/4/2021 11:23 AM, Tom Kunich wrote:
On Wednesday, February 3, 2021 at 7:51:14 PM UTC-8,
wrote:
On Wed, 3 Feb 2021 13:47:32 -0800 (PST), Tom Kunich
wrote:

On Wednesday, February 3, 2021 at 1:32:20 PM UTC-8,
wrote:
On Wed, 3 Feb 2021 11:10:58 -0800 (PST), Sir Ridesalot
wrote:

Isn't this the type of problem that the newer clutch-type rear
derailleurs were designed to stop?
Cheers
Yes.

The idea is to maintain the tension on the chain between the
chainwheel and rear derailleur. That should help prevent chain suck
if the chain is "glued" to the chainwheel by mud or crud. However, I
doubt it would provide sufficient tension to force the chain away from
a chainwheel that has hooked teeth. Also, notice that as the
chainwheel rotates past the point where the chain is expected to
release from the chainwheel, the holding force of a hooked tooth
increases. By the time the chain reaches the tail end of the front
derailleur, it's effectively locked in place by the hooked teeth. This
is probably why we don't see some kind of chain stripper attached to
the trailing end of the front derailleur. It would be really
difficult to provide enough rearward force on the chain to tear it
away from hooked teeth.

Full disclosu I've played with clutch type rear derailleurs on
other people's bicycles but have not tried one on mine. Not enough
experience with these to be certain that I haven't missed something.
Someone with more experience should be able to give a better answer.

I haven't seen that term used before. What is the difference between
the modern derailleur and the older type?
The difference between modern and older is one year or greater.
According to the dates on the relevant YouTube videos, the clutch
derailleurs started appearing about 4 years ago. I haven't been
paying attention and was informed that they exist a few weeks ago.

Google search finds a substantial number of articles on the topic,
along with a substantial number of opinions.
https://www.google.com/search?q=clutch+type+rear+derailleur
https://www.youtube.com/results?search_query=clutch+derailleur
I'm lacking in experience with clutch type rear derailleurs and
therefore can only refer you to the available articles and to suggest
you ask those with more experience.
--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
I wouldn't call that a clutch. I'd call it a derailleur arm ratchet
mechanism to maintain high pressure on the arm only in one direction.


I wouldn't either but Shimano does so it's a 'clutch'.
I wouldn't call clipless pedals "clipless pedals."

That misnomer arose because we called their predecessors "toe clips,"
which made no more sense. Those didn't clip. And clipless pedals do clip.

But what can you do?

Well, we can complain, and we can complain about "group set," or "frameset" too -- or crank(s) and axle/spindle, and whatever else Jobst used to complain about. And when did ten speed (cogs times chain rings) become ten speed (cogs only). I have a 22 speed! I want to complain about "tyres." It's "tires" -- just like wires, hires, and liars.

Jay, you're well on your way to becoming a grumpy old man. Welcome to
the club! ;-)

--
- Frank Krygowski

On Thu, 04 Feb 2021 14:05:37 -0600, AMuzi wrote:

On 2/4/2021 11:23 AM, Tom Kunich wrote:
I wouldn't call that a clutch. I'd call it a derailleur arm ratchet mechanism to maintain high pressure on the arm only in one direction.

I wouldn't either but Shimano does so it's a 'clutch'.

Well, the official name might be what the applicable patents call it.
Since Shimano uses "clutch" in all their advertising, I assumed that
Shimano would also do so in their patents. Nope. It's a "motion
resisting apparatus" or "motion resisting structure":
https://patents.google.com/?q=derailleur+clutch&assignee=shimano
For example:
https://patents.google.com/patent/US8202182B2/
I couldn't find anything under "derailleur ratchet" but might have
missed it. Looking at the bottom of the page from the above patent,
there is also:
SRAM "damper" and "fluid damper".
Shimano "derailleur with rotation resistance"
Shimano "Chain tensioning device"

I thought perhaps some other company might have trademarked
"derailleur clutch" but apparently, that's not the case:
http://tmsearch.uspto.gov Search TESS for "derailleur clutch" or
"derailleur ratchet". Nothing found.

There are 3 patents which mention "chain suck", none of which involve
an improved rear derailleur:
https://patents.google.com/?q=chain+suck



--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

On Thursday, February 4, 2021 at 10:16:14 PM UTC-8, wrote:
On Thu, 04 Feb 2021 14:05:37 -0600, AMuzi wrote:

On 2/4/2021 11:23 AM, Tom Kunich wrote:
I wouldn't call that a clutch. I'd call it a derailleur arm ratchet mechanism to maintain high pressure on the arm only in one direction.

I wouldn't either but Shimano does so it's a 'clutch'.
Well, the official name might be what the applicable patents call it.
Since Shimano uses "clutch" in all their advertising, I assumed that
Shimano would also do so in their patents. Nope. It's a "motion
resisting apparatus" or "motion resisting structure":
https://patents.google.com/?q=derailleur+clutch&assignee=shimano
For example:
https://patents.google.com/patent/US8202182B2/
I couldn't find anything under "derailleur ratchet" but might have
missed it. Looking at the bottom of the page from the above patent,
there is also:
SRAM "damper" and "fluid damper".
Shimano "derailleur with rotation resistance"
Shimano "Chain tensioning device"

I thought perhaps some other company might have trademarked
"derailleur clutch" but apparently, that's not the case:
http://tmsearch.uspto.gov Search TESS for "derailleur clutch" or
"derailleur ratchet". Nothing found.

There are 3 patents which mention "chain suck", none of which involve
an improved rear derailleur:
https://patents.google.com/?q=chain+suck

Are you saying that it is whatever Shimano decides to call it in their patent because if they use the common term "ratchet" it would be unpatentable?

On Fri, 5 Feb 2021 11:07:47 -0800 (PST), Tom Kunich
wrote:

On Thursday, February 4, 2021 at 10:16:14 PM UTC-8, wrote:
On Thu, 04 Feb 2021 14:05:37 -0600, AMuzi wrote:

On 2/4/2021 11:23 AM, Tom Kunich wrote:
I wouldn't call that a clutch. I'd call it a derailleur arm ratchet mechanism to maintain high pressure on the arm only in one direction.

I wouldn't either but Shimano does so it's a 'clutch'.
Well, the official name might be what the applicable patents call it.
Since Shimano uses "clutch" in all their advertising, I assumed that
Shimano would also do so in their patents. Nope. It's a "motion
resisting apparatus" or "motion resisting structure":
https://patents.google.com/?q=derailleur+clutch&assignee=shimano
For example:
https://patents.google.com/patent/US8202182B2/
I couldn't find anything under "derailleur ratchet" but might have
missed it. Looking at the bottom of the page from the above patent,
there is also:
SRAM "damper" and "fluid damper".
Shimano "derailleur with rotation resistance"
Shimano "Chain tensioning device"

I thought perhaps some other company might have trademarked
"derailleur clutch" but apparently, that's not the case:
http://tmsearch.uspto.gov Search TESS for "derailleur clutch" or
"derailleur ratchet". Nothing found.

There are 3 patents which mention "chain suck", none of which involve
an improved rear derailleur:
https://patents.google.com/?q=chain+suck

Are you saying that it is whatever Shimano decides to call it in their patent because if they use the common term "ratchet" it would be unpatentable?

No. I'm saying that if Shimano patents a device, and uses the
trademark or service mark registered by a different company for a
similar product, there might be some legal difficulties. I checked
and found that both "derailleur clutch" and "derailleur ratchet" have
not been trademarked and are therefore available for use by Shimano.

I'm not 100.00% certain that the common name is determined by the
patent holder. It could also be the manufacturer, the trade press,
enthusiast groups, forums, blogs, or internet "influencers".
Eventually, a common name floats to the surface, where it is
grudgingly declared by those involved to be the defacto name for the
device. It could quite literally be the name that is used most often
by the greatest number of users or promoters.

--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558

On Fri, 05 Feb 2021 22:33:17 -0800, Jeff Liebermann
wrote:

On Fri, 5 Feb 2021 11:07:47 -0800 (PST), Tom Kunich
wrote:

On Thursday, February 4, 2021 at 10:16:14 PM UTC-8, wrote:
On Thu, 04 Feb 2021 14:05:37 -0600, AMuzi wrote:

On 2/4/2021 11:23 AM, Tom Kunich wrote:
I wouldn't call that a clutch. I'd call it a derailleur arm ratchet mechanism to maintain high pressure on the arm only in one direction.

I wouldn't either but Shimano does so it's a 'clutch'.
Well, the official name might be what the applicable patents call it.
Since Shimano uses "clutch" in all their advertising, I assumed that
Shimano would also do so in their patents. Nope. It's a "motion
resisting apparatus" or "motion resisting structure":
https://patents.google.com/?q=derailleur+clutch&assignee=shimano
For example:
https://patents.google.com/patent/US8202182B2/
I couldn't find anything under "derailleur ratchet" but might have
missed it. Looking at the bottom of the page from the above patent,
there is also:
SRAM "damper" and "fluid damper".
Shimano "derailleur with rotation resistance"
Shimano "Chain tensioning device"

I thought perhaps some other company might have trademarked
"derailleur clutch" but apparently, that's not the case:
http://tmsearch.uspto.gov Search TESS for "derailleur clutch" or
"derailleur ratchet". Nothing found.

There are 3 patents which mention "chain suck", none of which involve
an improved rear derailleur:
https://patents.google.com/?q=chain+suck

Are you saying that it is whatever Shimano decides to call it in their patent because if they use the common term "ratchet" it would be unpatentable?

No. I'm saying that if Shimano patents a device, and uses the
trademark or service mark registered by a different company for a
similar product, there might be some legal difficulties. I checked
and found that both "derailleur clutch" and "derailleur ratchet" have
not been trademarked and are therefore available for use by Shimano.

I'm not 100.00% certain that the common name is determined by the
patent holder. It could also be the manufacturer, the trade press,
enthusiast groups, forums, blogs, or internet "influencers".
Eventually, a common name floats to the surface, where it is
grudgingly declared by those involved to be the defacto name for the
device. It could quite literally be the name that is used most often
by the greatest number of users or promoters.

But why ever not "clutch"? After all we have a "bottom bracket" when
there is no bracket at all. Or, as Frank commented, clip less pedals
that clip on, or brake shoes with no feet :-)
--
Cheers,

John B.

On 2/6/2021 1:32 AM, John B. wrote:
On Fri, 05 Feb 2021 22:33:17 -0800, Jeff Liebermann
wrote:

On Fri, 5 Feb 2021 11:07:47 -0800 (PST), Tom Kunich
wrote:

On Thursday, February 4, 2021 at 10:16:14 PM UTC-8, wrote:
On Thu, 04 Feb 2021 14:05:37 -0600, AMuzi wrote:

On 2/4/2021 11:23 AM, Tom Kunich wrote:
I wouldn't call that a clutch. I'd call it a derailleur arm ratchet mechanism to maintain high pressure on the arm only in one direction.

I wouldn't either but Shimano does so it's a 'clutch'.
Well, the official name might be what the applicable patents call it.
Since Shimano uses "clutch" in all their advertising, I assumed that
Shimano would also do so in their patents. Nope. It's a "motion
resisting apparatus" or "motion resisting structure":
https://patents.google.com/?q=derailleur+clutch&assignee=shimano
For example:
https://patents.google.com/patent/US8202182B2/
I couldn't find anything under "derailleur ratchet" but might have
missed it. Looking at the bottom of the page from the above patent,
there is also:
SRAM "damper" and "fluid damper".
Shimano "derailleur with rotation resistance"
Shimano "Chain tensioning device"

I thought perhaps some other company might have trademarked
"derailleur clutch" but apparently, that's not the case:
http://tmsearch.uspto.gov Search TESS for "derailleur clutch" or
"derailleur ratchet". Nothing found.

There are 3 patents which mention "chain suck", none of which involve
an improved rear derailleur:
https://patents.google.com/?q=chain+suck

Are you saying that it is whatever Shimano decides to call it in their patent because if they use the common term "ratchet" it would be unpatentable?

No. I'm saying that if Shimano patents a device, and uses the
trademark or service mark registered by a different company for a
similar product, there might be some legal difficulties. I checked
and found that both "derailleur clutch" and "derailleur ratchet" have
not been trademarked and are therefore available for use by Shimano.

I'm not 100.00% certain that the common name is determined by the
patent holder. It could also be the manufacturer, the trade press,
enthusiast groups, forums, blogs, or internet "influencers".
Eventually, a common name floats to the surface, where it is
grudgingly declared by those involved to be the defacto name for the
device. It could quite literally be the name that is used most often
by the greatest number of users or promoters.

But why ever not "clutch"? After all we have a "bottom bracket" when
there is no bracket at all. Or, as Frank commented, clip less pedals
that clip on, or brake shoes with no feet :-)


We're back to the dynamic nature of language.

In late 1800s England the steering assembly or 'set' is at
the 'head', not 'stern', of the thing. The crank bearing
assembly or 'bracket' is at the bottom. Concurrently,
Americans called that crank bearing assembly a 'hanger'.

As an aside, we seldom use the term 'bottom bracket' with
customers, preferring. 'crank bearing'.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971

On Fri, 05 Feb 2021 22:33:17 -0800, Jeff Liebermann
wrote:

On Fri, 5 Feb 2021 11:07:47 -0800 (PST), Tom Kunich
wrote:

On Thursday, February 4, 2021 at 10:16:14 PM UTC-8, wrote:
On Thu, 04 Feb 2021 14:05:37 -0600, AMuzi wrote:

On 2/4/2021 11:23 AM, Tom Kunich wrote:
I wouldn't call that a clutch. I'd call it a derailleur arm ratchet mechanism to maintain high pressure on the arm only in one direction.

I wouldn't either but Shimano does so it's a 'clutch'.
Well, the official name might be what the applicable patents call it.
Since Shimano uses "clutch" in all their advertising, I assumed that
Shimano would also do so in their patents. Nope. It's a "motion
resisting apparatus" or "motion resisting structure":
https://patents.google.com/?q=derailleur+clutch&assignee=shimano
For example:
https://patents.google.com/patent/US8202182B2/
I couldn't find anything under "derailleur ratchet" but might have
missed it. Looking at the bottom of the page from the above patent,
there is also:
SRAM "damper" and "fluid damper".
Shimano "derailleur with rotation resistance"
Shimano "Chain tensioning device"

I thought perhaps some other company might have trademarked
"derailleur clutch" but apparently, that's not the case:
http://tmsearch.uspto.gov Search TESS for "derailleur clutch" or
"derailleur ratchet". Nothing found.

There are 3 patents which mention "chain suck", none of which involve
an improved rear derailleur:
https://patents.google.com/?q=chain+suck

Are you saying that it is whatever Shimano decides to call it in their patent because if they use the common term "ratchet" it would be unpatentable?

No. I'm saying that if Shimano patents a device, and uses the
trademark or service mark registered by a different company for a
similar product, there might be some legal difficulties. I checked
and found that both "derailleur clutch" and "derailleur ratchet" have
not been trademarked and are therefore available for use by Shimano.

I'm not 100.00% certain that the common name is determined by the
patent holder. It could also be the manufacturer, the trade press,
enthusiast groups, forums, blogs, or internet "influencers".
Eventually, a common name floats to the surface, where it is
grudgingly declared by those involved to be the defacto name for the
device. It could quite literally be the name that is used most often
by the greatest number of users or promoters.

It seems that Shimano was also calling their device a "chain
stabilizer":
https://www.performancebike.com/shimano-rear-derailleur-chain-stabilizer-y5pv98040/p498434
The videos below include teardowns and some detail on how the rotary
clutch works, adjustment, cleaning, lubrication, etc.

Shimano Clutch Repair, Adjustment, Maintenance How To - M9100, M9000,
M8000, M7000,M786, M675, M640 (2016)
https://www.youtube.com/watch?v=zGdkAE_y_aE

CLUTCH SERVICE? Shimano 12, 11, 10 speed XTR, XT, SLX, Deore - Shadow
Plus Derailleur Maintenance (2020)
https://www.youtube.com/watch?v=Ztf38cO2Ej4

Shimano Shadow + (Plus) Clutch Adjustment, Repair, Maintenance RD-M675
M786 M615 SLX XT Deore (2014)
https://www.youtube.com/watch?v=wV6W4PKDUrU

How To Fix *FAULTY SHIMANO DERAILLEUR CLUTCH* (2020)
https://www.youtube.com/watch?v=2uZr3E03q8k

--
Jeff Liebermann
PO Box 272 http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558