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GD cable derailleurs!



 
 
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  #21  
Old April 8th 21, 07:53 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Default GD cable derailleurs!

On 4/8/2021 2:22 PM, Tom Kunich wrote:


People who pretend to be engineers are tiring.


You're telling us?? ;-)

--
- Frank Krygowski, Licensed Professional Engineer (retired)
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  #22  
Old April 8th 21, 08:08 PM posted to rec.bicycles.tech
Tom Kunich[_4_]
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Posts: 2,196
Default GD cable derailleurs!

On Thursday, April 8, 2021 at 11:53:57 AM UTC-7, Frank Krygowski wrote:
On 4/8/2021 2:22 PM, Tom Kunich wrote:


People who pretend to be engineers are tiring.

You're telling us?? ;-)


I have 50 years of accomplishments at the highest levels. Tell us what you have added to the modern technology.
  #23  
Old April 8th 21, 08:16 PM posted to rec.bicycles.tech
JBeattie
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Posts: 5,870
Default GD cable derailleurs!

On Thursday, April 8, 2021 at 10:49:48 AM UTC-7, wrote:
On Thu, 8 Apr 2021 05:43:43 -0700 (PDT), Tom Kunich
wrote:

Jeff, try picturing threading a Kevlar inner cable through the outer. Now how
would you expect to do that?

Two ways. Pull or push. For pull, I would run a metal wire through
the cable housing, attach to Kevlar fiber with glue, and pull on the
metal wire. For push, I would glue a wad of cotton to form a shuttle
on the end of the Kevlar fiber. A conical dart shape should work.
Insert the shuttle into the cable housing and blow it through housing
using compressed air.
https://en.wikipedia.org/wiki/Cable_jetting
As a real engineer I have some ideas that could work but why when
stainless steel is more than sufficient. Jay is a lawyer and not a
mechanic. We all know that he broke a cable probably because he
overtightened it at the derailleur and broke the strands.

We all don't know that. You might, but we don't.
Stainless is extremely good at weather resistance but very bad at
pressures that overload the molecular bond of the material.

Pressure? Stainless is excellent in compression (also known as
pressure) but might have problems in tension or torsion.


Pfff. I've been a bike mechanic since I had bikes, and I worked in a shop . . . and I had my own wheel building business in college . . . and Trek installed the cable. It was OE on my Emonda. And how do you over tighten an STI cable? It has to be adequately tensioned for index shifting. That makes no sense at all. The cable broke in the lever at the usual place -- about an inch behind the head, inside the lever. https://photos.app.goo.gl/Hoi29kauY5SW767m9 This should be where Tom criticizes the Japanese engineers who designed the 8000 series for not coming up with something that didn't involve winding-up a cable. There should be some hydraulic, linear-pull mechanism with digital controls and a fray-o-meter indicating when failure is imminent. Safety inflation!

-- Jay Beattie.
  #24  
Old April 8th 21, 08:30 PM posted to rec.bicycles.tech
Tom Kunich[_4_]
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Posts: 2,196
Default GD cable derailleurs!

On Tuesday, April 6, 2021 at 9:09:14 PM UTC-7, jbeattie wrote:
A few miles into my evening ride on my cable-shift Emonda -- with my wife pushing me on her ebike, I shifted to go up the next hill and snap -- immediate downshift into 34/11. Great. In the middle of a 9% grade, that turned at the top to another climb, but a short one. I tacked a bit, got home and then jumped on the Di2 disc Synapse and started over. Heavier with fenders, etc., but still a nice bike. The discs, BTW, don't drag at all. Thank Buddha for that reliable Di2.

The good thing about the latest Ultegra levers is that there is a trap door under the lever body, and you can remove one screw, take out the door and grab the broken cable and end. No more fishing it out of the lever. This is the second time in 20 years on STI that I've broken a cable. Before that I broke a friction bar-end cable in the middle of a tour. I had a spare.


Jay, I wasn't taking a pot shot at you for overtightening a cable. Most people that do not work on bicycle stuff a whole lot do the same thing. When I'm building bikes up I usually do not tighten things up as much as I might because of this danger. I just finished the Eddy Merckx yesterday and took it out on a ride today. I did a flat 30 miles to see if everything worked well. First problem was the I hadn't set the stem dead center forwards. Second was that rather than Look Keo's I have bought a set of Rock Bros's copies. These actually work pretty well but the seals and bearing grease have to be "broken in" for the pedal to rotate to BDC so that you can kick into the pedal without looking. The rear derailleur wasn't perfectly aligned and so the gears were jumping in about half the ratios. This will be the hardest to resolve since I have a Chinese Campy-type cassette and I suspect they have Shimano spacing so I'll have to put a Campy 10 speed on it. I have plenty of 12-28's but aside from this one being very light, it is an 11-28. No big deal but it makes a difference on fast downhill descents. The front derailleur threw the chain for no reason I could see, though I suspect that I might have leaned on the lever going over some bumps. I had also inflated the tires to the 25 mm level instead of the 28 which is 10 psi less. So I was rather rough over the bumps. It was even making my sunglasses mounted rear view mirror move around.

The point of this is that your kind of problem is common. Everyone makes mistakes and it wasn't the cable that was at fault so don't glamorize the Di2 because it doesn't have that particular problem. The Di2 routing on my Colnago should have been the left lever along the top tube to the seat tube and from there down the to the four way connector block. However, there is NO hole between the top tube and the seat tube on that bike. So the wire runs in at an angle facing rearwards but then has to reverse course and go down the head tube and down tube to achieve the same thing that takes up a longer wire than necessary. So there are problems with Di2 and you can expect a LOT more problems with the new "wireless" 12 speed stuff since you have to shift through so many gears to get anywhere.

I have to admit, it was a real pleasure to ride a 10 speed again and I'm sure that a 9 speed would be better. You and I are not racers anymore and it grows tiresome shifting though gears that are only necessary to a 450 watt rider going for a TT record.
  #25  
Old April 8th 21, 08:41 PM posted to rec.bicycles.tech
Tom Kunich[_4_]
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Posts: 2,196
Default GD cable derailleurs!

On Thursday, April 8, 2021 at 12:16:39 PM UTC-7, jbeattie wrote:
On Thursday, April 8, 2021 at 10:49:48 AM UTC-7, wrote:
On Thu, 8 Apr 2021 05:43:43 -0700 (PDT), Tom Kunich
wrote:

Jeff, try picturing threading a Kevlar inner cable through the outer. Now how
would you expect to do that?

Two ways. Pull or push. For pull, I would run a metal wire through
the cable housing, attach to Kevlar fiber with glue, and pull on the
metal wire. For push, I would glue a wad of cotton to form a shuttle
on the end of the Kevlar fiber. A conical dart shape should work.
Insert the shuttle into the cable housing and blow it through housing
using compressed air.
https://en.wikipedia.org/wiki/Cable_jetting
As a real engineer I have some ideas that could work but why when
stainless steel is more than sufficient. Jay is a lawyer and not a
mechanic. We all know that he broke a cable probably because he
overtightened it at the derailleur and broke the strands.

We all don't know that. You might, but we don't.
Stainless is extremely good at weather resistance but very bad at
pressures that overload the molecular bond of the material.

Pressure? Stainless is excellent in compression (also known as
pressure) but might have problems in tension or torsion.

Pfff. I've been a bike mechanic since I had bikes, and I worked in a shop . . . and I had my own wheel building business in college . . . and Trek installed the cable. It was OE on my Emonda. And how do you over tighten an STI cable? It has to be adequately tensioned for index shifting. That makes no sense at all. The cable broke in the lever at the usual place -- about an inch behind the head, inside the lever. https://photos.app.goo.gl/Hoi29kauY5SW767m9 This should be where Tom criticizes the Japanese engineers who designed the 8000 series for not coming up with something that didn't involve winding-up a cable. There should be some hydraulic, linear-pull mechanism with digital controls and a fray-o-meter indicating when failure is imminent. Safety inflation!


You overtighten it by turning the locking screw too tightly or perhaps having a washer with a sharp edge on it. If it was OEM that means that it was probably improperly threaded through the locking mechanism down on the rear derailleur and simply took this long to break. None of those washers and stops is very intuitive and it is quite easy to run the cables through there incorrectly and put an un-designed for load on the cable. Perhaps they used 105 inner and outers which is 20% the quality of the Dura Ace cable set.

Like I say, I'm not knocking you because these things are easy to do if you aren't really careful. I only use Record cable sets and cut them ONLY with a Park cable clipper. I have used several other cable cutters and they ALL cut crooked. Especially on the Brake Outer Cables.
  #26  
Old April 8th 21, 09:21 PM posted to rec.bicycles.tech
JBeattie
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Posts: 5,870
Default GD cable derailleurs!

On Thursday, April 8, 2021 at 12:41:34 PM UTC-7, wrote:
On Thursday, April 8, 2021 at 12:16:39 PM UTC-7, jbeattie wrote:
On Thursday, April 8, 2021 at 10:49:48 AM UTC-7, wrote:
On Thu, 8 Apr 2021 05:43:43 -0700 (PDT), Tom Kunich
wrote:

Jeff, try picturing threading a Kevlar inner cable through the outer.. Now how
would you expect to do that?
Two ways. Pull or push. For pull, I would run a metal wire through
the cable housing, attach to Kevlar fiber with glue, and pull on the
metal wire. For push, I would glue a wad of cotton to form a shuttle
on the end of the Kevlar fiber. A conical dart shape should work.
Insert the shuttle into the cable housing and blow it through housing
using compressed air.
https://en.wikipedia.org/wiki/Cable_jetting
As a real engineer I have some ideas that could work but why when
stainless steel is more than sufficient. Jay is a lawyer and not a
mechanic. We all know that he broke a cable probably because he
overtightened it at the derailleur and broke the strands.
We all don't know that. You might, but we don't.
Stainless is extremely good at weather resistance but very bad at
pressures that overload the molecular bond of the material.
Pressure? Stainless is excellent in compression (also known as
pressure) but might have problems in tension or torsion.

Pfff. I've been a bike mechanic since I had bikes, and I worked in a shop . . . and I had my own wheel building business in college . . . and Trek installed the cable. It was OE on my Emonda. And how do you over tighten an STI cable? It has to be adequately tensioned for index shifting. That makes no sense at all. The cable broke in the lever at the usual place -- about an inch behind the head, inside the lever. https://photos.app.goo.gl/Hoi29kauY5SW767m9 This should be where Tom criticizes the Japanese engineers who designed the 8000 series for not coming up with something that didn't involve winding-up a cable. There should be some hydraulic, linear-pull mechanism with digital controls and a fray-o-meter indicating when failure is imminent. Safety inflation!

You overtighten it by turning the locking screw too tightly or perhaps having a washer with a sharp edge on it. If it was OEM that means that it was probably improperly threaded through the locking mechanism down on the rear derailleur and simply took this long to break. None of those washers and stops is very intuitive and it is quite easy to run the cables through there incorrectly and put an un-designed for load on the cable. Perhaps they used 105 inner and outers which is 20% the quality of the Dura Ace cable set.

Like I say, I'm not knocking you because these things are easy to do if you aren't really careful. I only use Record cable sets and cut them ONLY with a Park cable clipper. I have used several other cable cutters and they ALL cut crooked. Especially on the Brake Outer Cables.


Did you look at the picture? The cable didn't break at the cable anchor (if that's what you mean by "locking screw"). There is no way that an installation error would cause a cable failure in the lever, except possibly lack of lubrication or maybe a bad cable guide in the lever, which I did not see. Who knows if the cable was sub-par, and there is no such thing as Shimano 105 inner cable -- although they have marketed some inner cable as Dura Ace. AFAIK, all the SS cables are the same but with different coatings, many of which become fuzzy with use. I stick with uncoated SS.

-- Jay Beattie.

  #27  
Old April 8th 21, 09:29 PM posted to rec.bicycles.tech
Ralph Barone[_4_]
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Posts: 853
Default GD cable derailleurs!

Frank Krygowski wrote:
On 4/8/2021 2:22 PM, Tom Kunich wrote:


People who pretend to be engineers are tiring.


You're telling us?? ;-)


Agreed.

Ralph Barone, BASc, PEng

  #28  
Old April 8th 21, 10:22 PM posted to rec.bicycles.tech
Roger Merriman[_4_]
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Posts: 385
Default GD cable derailleurs!

Tom Kunich wrote:
On Thursday, April 8, 2021 at 5:32:07 AM UTC-7, Roger Merriman wrote:
James wrote:
On 7/4/21 2:09 pm, jbeattie wrote:
A few miles into my evening ride on my cable-shift Emonda -- with my
wife pushing me on her ebike, I shifted to go up the next hill and
snap -- immediate downshift into 34/11. Great. In the middle of a
9% grade, that turned at the top to another climb, but a short one.
I tacked a bit, got home and then jumped on the Di2 disc Synapse and
started over. Heavier with fenders, etc., but still a nice bike.
The discs, BTW, don't drag at all. Thank Buddha for that reliable
Di2.

The good thing about the latest Ultegra levers is that there is a
trap door under the lever body, and you can remove one screw, take
out the door and grab the broken cable and end. No more fishing it
out of the lever. This is the second time in 20 years on STI that
I've broken a cable. Before that I broke a friction bar-end cable in
the middle of a tour. I had a spare.


I guess when you've been riding the Di2 setup for the same time &
distance you'll be able to make a more reasonable comparison.

I'm still waiting to break a cable after more than 30 years of using
cable actuated gears and brakes.

I tend to have to replace as the cable gets sticky, and after a while can’t
be cleaned/lubed into life.

Don’t think I’ve ever snapped a cable. Mind you until this year had never
snapped a hanger...


Now that they are making replaceable hangers the aluminum material is of
the wrong alloy and is very brittle. I don't think that this is to allow
break away in case of a crash or to make people buy more of them but
simply that alloy is just cheaper than hell. It appears to be almost pure aluminum.

These where both OEM parts, ie two separate bikes, one is fairly new, other
is 6 or 7 years old now. In both cases due to COVID19 restrictions I was
riding in well bog.

Ie have no reason to believe was any design fault.

Roger Merriman.

  #29  
Old April 8th 21, 10:49 PM posted to rec.bicycles.tech
Jeff Liebermann
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Posts: 4,018
Default GD cable derailleurs!

On Thu, 8 Apr 2021 11:22:28 -0700 (PDT), Tom Kunich
wrote:

People who pretend to be engineers are tiring.


Hmmm... I'm not tired. Therefore, I must be an engineer.

You have already told us that you only rarely ride a bicycle anymore


That's mostly correct. What I actually said before you twisted the
meaning is that I am no longer able to properly ride a bicycle. If
you want, I can explain the medical problem that created this
situation. I still have two bicycles, which I occasionally ride short
distances.

so perhaps you might want to explain what you're even doing on this group?


Perhaps? That suggests that I can perhaps choose not to explain. So,
I won't explain because you don't need to know and I don't feel like
justifying my presence.

However, I can offer you a fair trade. I'll answer your question if
you explain why you reply to every single thread, statement, question,
and comment in R.B.T. I believe that I understand the motivations for
your other odd habits, but the need to add your uninformed and
unsubstantiated opinion to every discussion has me mystified. Why?

You probably don't trust me to provide a genuine answer to your
question, so I'll go first if you agree to answer my question in a
similar manner. Deal?

--
Jeff Liebermann
PO Box 272
http://www.LearnByDestroying.com
Ben Lomond CA 95005-0272
Skype: JeffLiebermann AE6KS 831-336-2558
  #30  
Old April 8th 21, 10:53 PM posted to rec.bicycles.tech
Tom Kunich[_4_]
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Posts: 2,196
Default GD cable derailleurs!

On Thursday, April 8, 2021 at 1:21:27 PM UTC-7, jbeattie wrote:
On Thursday, April 8, 2021 at 12:41:34 PM UTC-7, wrote:
On Thursday, April 8, 2021 at 12:16:39 PM UTC-7, jbeattie wrote:
On Thursday, April 8, 2021 at 10:49:48 AM UTC-7, wrote:
On Thu, 8 Apr 2021 05:43:43 -0700 (PDT), Tom Kunich
wrote:

Jeff, try picturing threading a Kevlar inner cable through the outer. Now how
would you expect to do that?
Two ways. Pull or push. For pull, I would run a metal wire through
the cable housing, attach to Kevlar fiber with glue, and pull on the
metal wire. For push, I would glue a wad of cotton to form a shuttle
on the end of the Kevlar fiber. A conical dart shape should work.
Insert the shuttle into the cable housing and blow it through housing
using compressed air.
https://en.wikipedia.org/wiki/Cable_jetting
As a real engineer I have some ideas that could work but why when
stainless steel is more than sufficient. Jay is a lawyer and not a
mechanic. We all know that he broke a cable probably because he
overtightened it at the derailleur and broke the strands.
We all don't know that. You might, but we don't.
Stainless is extremely good at weather resistance but very bad at
pressures that overload the molecular bond of the material.
Pressure? Stainless is excellent in compression (also known as
pressure) but might have problems in tension or torsion.
Pfff. I've been a bike mechanic since I had bikes, and I worked in a shop . . . and I had my own wheel building business in college . . . and Trek installed the cable. It was OE on my Emonda. And how do you over tighten an STI cable? It has to be adequately tensioned for index shifting. That makes no sense at all. The cable broke in the lever at the usual place -- about an inch behind the head, inside the lever. https://photos.app.goo.gl/Hoi29kauY5SW767m9 This should be where Tom criticizes the Japanese engineers who designed the 8000 series for not coming up with something that didn't involve winding-up a cable. There should be some hydraulic, linear-pull mechanism with digital controls and a fray-o-meter indicating when failure is imminent. Safety inflation!

You overtighten it by turning the locking screw too tightly or perhaps having a washer with a sharp edge on it. If it was OEM that means that it was probably improperly threaded through the locking mechanism down on the rear derailleur and simply took this long to break. None of those washers and stops is very intuitive and it is quite easy to run the cables through there incorrectly and put an un-designed for load on the cable. Perhaps they used 105 inner and outers which is 20% the quality of the Dura Ace cable set.

Like I say, I'm not knocking you because these things are easy to do if you aren't really careful. I only use Record cable sets and cut them ONLY with a Park cable clipper. I have used several other cable cutters and they ALL cut crooked. Especially on the Brake Outer Cables.

Did you look at the picture? The cable didn't break at the cable anchor (if that's what you mean by "locking screw"). There is no way that an installation error would cause a cable failure in the lever, except possibly lack of lubrication or maybe a bad cable guide in the lever, which I did not see. Who knows if the cable was sub-par, and there is no such thing as Shimano 105 inner cable -- although they have marketed some inner cable as Dura Ace. AFAIK, all the SS cables are the same but with different coatings, many of which become fuzzy with use. I stick with uncoated SS.

-- Jay Beattie.

Jay, I didn't see any picture showing the broken cable and must have missed that the cable broke at that damned sharp turn that they have on the latest Shimano levers. I wondered about that turn the first time I set a Shimano 105 up. There a much better designs that would completely avoid that turn altogether and have the shift cable go through the front of the lever similar to the brake cable. They even have everything in the assembly to use to do it.
 




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