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mechanical details on the movement of the Campagnolo 8sp rear derailleur

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mechanical details on the movement of the Campagnolo 8sp rear derailleur

Old 09-23-23, 05:03 PM
  #76  
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Originally Posted by 79pmooney
I thought I read in an earlier post that the OP was not a fan of batteries and wired/wireless shifting. I was just trying to help out with accurately measuring cable runs between shifts for someone who might have the machinist skills and consider it fun to make his own index system.

I am not a fan of Shimano's really easy shifting cogs for friction shifting because if I put the derailleur between cogs, the chain has a very disconcerting tendency to wander between the cogs as I increase or decrease pedaling pressure, almost always in the wrong direction. (Modern Shimano freewheels. I've never had their cassettes.) My Campy 9-speed cassettes almost always pick one cog and stay there or maybe, shift once. The shifting is cruder than say the Shimano FWs I've had on other bikes but that super smooth Mirage makes up for that and more. Likewise my older Sachs FWs never wander and do no more than shift once when I screw up. (When I want a very different gear, I expect to be able the just toss the lever forward of back, get out of the saddle and be in a gear that works and is within a cog or so of my intended. I took that for granted when I raced in the 70s and still do.
When I recut a Campy Syncro insert to work with Shimano 8 speed, I just put the lever in friction and recorded the necessary lever angles for the individual cogs, then cut the new detents at those same points. It worked, and there was less possibility of making a translation error.

The OP seems to be making a battery operated solenoid that pulls a cable. He is avoiding multiple wires and multiple batteries by using a cable.


I think the "in between gears" thing is what I was talking about - you can run the pulley really close to the cogs to get quick shifts, or run them farther away and use a more affirmative cog design. If you run close you need to make very accurate shift lever placements or you'll either get ghost shifts or chain noise. It would seem to me that if you aren't getting the ghost shifts that you get with HG cogs, you are still getting a fair amount of noise from chain not being centered. So you might consider running your B screw tighter (or Campy equivalent), so your chain has a bit more distance to absorb misalignment. But my favorite friction shifting is an HG cog and an inch or so of pulley distance coupled with a Simplex retrofriction shifter.

However, the longer cable pull of the '90s Campy/Sachs derailleurs might mate very well to the Suntour ratchet shifters because they will seem less granular having to move more degrees of shifter angle between each cog. I was going to try that with my next build.
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Old 09-23-23, 05:50 PM
  #77  
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Originally Posted by smd4
Which isnít necessary.
Yeah, what do those Shimano engineers know, they can't even glue a crankset together...
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Old 09-23-23, 05:53 PM
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Originally Posted by wheelreason
yeah, what do those shimano engineers know, they can't even glue a crankset together...
lol!
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Old 09-24-23, 01:05 AM
  #79  
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Originally Posted by DiTBho
I don't trust it enough, also I don't like to have several batteries(2). You have to periodically check the charge, you have to replace. Too annoying for me.

I khow encryption works and how there is always a way to exploit some software or hardware bug, so I don't want to spend more time on something that needs extra care to only be at best "reliable enough" with always a margin of risk.

Now they sell and advertise on YouTube and Facebook an orange device (I won't tell you the name) that also hacks traffic lights and allows you to pass the subway barrier for free(1), and there are a lot of idiots who buy it and then go around to disturb people.

Imagine if you met one of these idiots who, for a laugh, made you change gear uphill, perhaps in one of those crossed positions to avoid.

No, it's not for me! My philosophy is: don't keep more ports open on your router than you really need, never do something wireless if you can do without it.


(1) it's not hypothetical, they did and filmed it, and uploaded it to Youtube... damn how it depressed me to see this idiotic use of technology. Even worse when they used that device to hack coffee and drink vending machines, with the result that the company that manages them got pissed off and increased the price of the drinks.

(2) batteries:
- one battery for the wireless speed meter?
- one battery for the wireless cadence sensor?
- one battery for the wireless rear deraillerur?
- one battery for the wireless front deraillerur?
- one battery for the wireless front led?
- one battery for the wireless rear position light?
how many bloody batteries do you have? and how many wireless channels do you use?
no way, all wired, only one battery for everything!
I work in software so I know youíre right about bugs but those are always fhe result of careless coding / ignorance of security architecture. So I donít think anyone buying a product where this problem is very obvious from the start has much risk but youíre right that for a hobby project itís a lot of extra complexity.

You forgot batteries for power meter, Garmin and HRM
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Old 09-24-23, 03:59 AM
  #80  
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Originally Posted by choddo
I work in software so I know you’re right about bugs but those are always fhe result of careless coding / ignorance of security architecture. So I don’t think anyone buying a product where this problem is very obvious from the start has much risk but you’re right that for a hobby project it’s a lot of extra complexity.
Yup, and it's also a question of costs!

I've worked for years on avionics firmware testing, DO178B etc., and "I've seen things that you humans..." (quote, from BladeRunner) ...that is, from supersonic planes to airliners to cargo planes, we go through thousands and thousands and thousands of hours of work on test reports (QA-supervised testing activities), and this is something that is never done in the rest(1) of the software industry, not for phones, much less for bicycle devices, which instead are classified as "level E", meaning even if they contain a bug they will never cause material damage or death of people, so you can imagine how superficial the tests were.

And this for a very specific reason: those who do software testing must be constantly trained (new tools, new procedures, etc.), preferably they should be a software engineer, and professional figures of this type are needed in geometry progression both with complexity of the software to be tested both with the level { A, B, C, D, E } of the DO178B specifications that you want to follow, and in any case they are salaries to be paid, and the equipment they use are typically expensive, all costs which then affect the selling price, which must be competitive... and therefore we cut where we can cut.

That little bloody idiotic orange gadget I was talking about can crash both traffic lights and coffee vending machines, just like the "aircrack" program (now "Aircrack-ng") can crack your WPA/WPA2 Wi-Fi password, there are people on YouTube who say you have to do it "to prank their neighbors" or "the unfortunate people who pass by them in shopping centers", go figure if no one thinks about it by exploiting it for "bluebugging" (Bluetooth cracking) even when you're riding your bike and trying to climb a hill (sure, they will!)

You can also find articles about Bluetooth PIN Cracking, but basically you can cause annoyance by simply preventing the transmitter from reaching the receiver.

It's that if you come across one of these "joking dudes" (Jokers?) ... it will only be him or her who will have a laugh, while you will be less than happy that you have been hacked, and you understand that it bothers me a lot also due to professional deformation: I'm one of those who does testing, and then like a fool I get my bicycle hacked?

LOL

Originally Posted by choddo
You forgot batteries for power meter, Garmin and HRM
Yup, added to the list.
(I wouldn't buy them, the list was already exaggerated, so now it's doubled in exaggeration)

(1) {Naval, (high-speed) rail, medical, avionics, and nuclear facilities} have stringent software testing requirements and guidelines; other branches have less, little or even nothing (e.g. Arduino).

Last edited by DiTBho; 09-24-23 at 04:13 AM.
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Old 09-24-23, 04:16 AM
  #81  
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Originally Posted by DiTBho
Which software? Management? Domotic? Automotive? Naval? Railway (high-speed)? Medical? Avionics? Nuclear implants? ...

I've worked for years on avionics firmware testing, DO178B etc., and "I've seen things that you humans..." (quote, from BladeRunner) ...that is, from supersonic planes to airliners to cargo planes, we go through thousands and thousands and thousands of hours of work on test reports (QA-supervised testing activities), and this is something that is never done in the rest(1) of the software industry, not for phones, much less for bicycle devices, which instead are classified as "level E", meaning even if they contain a bug they will never cause material damage or death of people, so you can imagine how superficial the tests were.

And this for a very specific reason: those who do software testing must be constantly trained (new tools, new procedures, etc.), preferably they should be a software engineer, and professional figures of this type are needed in geometry progression both with complexity of the software to be tested both with the level { A, B, C, D, E } of the DO178B specifications that you want to follow, and in any case they are salaries to be paid, and the equipment they use are typically expensive, all costs which then affect the selling price, which must be competitive... and therefore we cut where we can cut.

That little bloody idiotic orange gadget I was talking about can crash both traffic lights and coffee vending machines, just like the "aircrack" program (now "Aircrack-ng") can crack your WPA/WPA2 Wi-Fi password, there are people on YouTube who say you have to do it "to prank their neighbors" or "the unfortunate people who pass by them in shopping centers", go figure if no one thinks about it by exploiting it for "bluebugging" (Bluetooth cracking) even when you're riding your bike and trying to climb a hill (sure, they will!)

You can also find articles about Bluetooth PIN Cracking, but basically you can cause annoyance by simply preventing the transmitter from reaching the receiver.

So, it's not that it's hypothetical, it's that if you come across one of these "dudes" ... it will only be him or her who will have a laugh, while you will be less than happy that you have been hacked, and you understand that it bothers me a lot also due to professional deformation: I'm one of those who does testing, and then like a fool I get my bicycle hacked?

LOL



Yup, added to the list.
(I wouldn't buy them, the list was already exaggerated, so now it's doubled in exaggeration)

(1) {Naval, (high-speed) rail, medical, avionics, and nuclear facilities} have stringent software testing requirements and guidelines; other branches have less, little or even nothing (e.g. Arduino).
I used to work for IBM and now work for a cloud infrastructure company so basically ďall of the aboveĒ because I have always worked cross industry with clients, some of whom are subject to that level of quality engineering requirement but they all pay attention to security these days. I am one step removed so I get it, but donít have to do it myself thankfully.

Oh and afaik Aircrack-ng canít do anything terribly clever with WPA2. It just brute-forces.

Last edited by choddo; 09-24-23 at 06:43 AM.
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Old 09-24-23, 06:29 AM
  #82  
wheelreason
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Originally Posted by DiTBho
Yup, and it's also a question of costs!

I've worked for years on avionics firmware testing, DO178B etc., and "I've seen things that you humans..." (quote, from BladeRunner) ...that is, from supersonic planes to airliners to cargo planes, we go through thousands and thousands and thousands of hours of work on test reports (QA-supervised testing activities), and this is something that is never done in the rest(1) of the software industry, not for phones, much less for bicycle devices, which instead are classified as "level E", meaning even if they contain a bug they will never cause material damage or death of people, so you can imagine how superficial the tests were.

And this for a very specific reason: those who do software testing must be constantly trained (new tools, new procedures, etc.), preferably they should be a software engineer, and professional figures of this type are needed in geometry progression both with complexity of the software to be tested both with the level { A, B, C, D, E } of the DO178B specifications that you want to follow, and in any case they are salaries to be paid, and the equipment they use are typically expensive, all costs which then affect the selling price, which must be competitive... and therefore we cut where we can cut.

That little bloody idiotic orange gadget I was talking about can crash both traffic lights and coffee vending machines, just like the "aircrack" program (now "Aircrack-ng") can crack your WPA/WPA2 Wi-Fi password, there are people on YouTube who say you have to do it "to prank their neighbors" or "the unfortunate people who pass by them in shopping centers", go figure if no one thinks about it by exploiting it for "bluebugging" (Bluetooth cracking) even when you're riding your bike and trying to climb a hill (sure, they will!)

You can also find articles about Bluetooth PIN Cracking, but basically you can cause annoyance by simply preventing the transmitter from reaching the receiver.

It's that if you come across one of these "joking dudes" (Jokers?) ... it will only be him or her who will have a laugh, while you will be less than happy that you have been hacked, and you understand that it bothers me a lot also due to professional deformation: I'm one of those who does testing, and then like a fool I get my bicycle hacked?

LOL



Yup, added to the list.
(I wouldn't buy them, the list was already exaggerated, so now it's doubled in exaggeration)

(1) {Naval, (high-speed) rail, medical, avionics, and nuclear facilities} have stringent software testing requirements and guidelines; other branches have less, little or even nothing (e.g. Arduino).
F35 lately?...
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