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  #11  
Old June 15th 21, 07:24 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
Default More Shifting Problems

On 6/15/2021 1:29 PM, Lou Holtman wrote:
On Tuesday, June 15, 2021 at 5:37:08 PM UTC+2, Frank Krygowski wrote:
On 6/15/2021 10:42 AM, Tom Kunich wrote:
On Monday, June 14, 2021 at 7:08:25 PM UTC-7, Frank Krygowski wrote:
On 6/14/2021 3:12 PM, Tom Kunich wrote:
On Monday, June 14, 2021 at 8:55:36 AM UTC-7, jbeattie wrote:

Your limit screw should not have any effect on the shifting in the middle of the cassette. Your problems sound like cable tension or a bent derailleur hanger or worn cogs in the middle of your cassette. Whether your derailleur pulleys have bearings or bushings isn't going to make any difference, although worn teeth may affect shifting.

Where did I say anything at all about the limit screw having anything to do with anything but to keep a derailleur from overshifting? While out on a ride I overshifted the rear derailleur. I caught it before there was any damage to the wheel but I did not want to overshift again so I readjusted the rear derailleur tension so that it would not overshift. That unfortunately screwed up the shifting so I had to ride in gears that were not effected.

Don't tell me you wouldn't do the same thing if you didn't have a screwdriver of the proper size to reset the limit screw.
Despite your long history of mechanical mishaps, you really went on a
bike ride with no tool capable of adjusting a tiny screw?

Why?? To save weight??

There is a reason that I was successful and you were a nothing that did nothing - I had the sense to know that simply turning an adjustment screw would get me back 10 miles where I could properly adjust things. People like you stop and block roads until cars get tired of your stupid bull****.

No, people like me turn the proper screw and ride on.

It sounds like you messed with cable length adjustment, screwing up your
shifting, when you should have messed with the limit screw and left your
shift levers in synch with your cog spacing.

Again: You should consider keeping your mistakes secret. You continually
tell us about your incompetence.


--
- Frank Krygowski



Again limit screws have nothing to do with the adjustment of your RD. I once explained that to a friend with a simple drawing:

https://photos.app.goo.gl/xT6x8vfz4hRwx9Y9A

If the chain is jumping between gears than:
- RD is not adjusted right,
- bent RD hanger,
- upper pulley wheel has to much radial play causing hysteresis which makes adjustment near impossible,
- B screw adjustment way off,
- outer plate of a chain link displaced,
- wrong cassette,
- the overshift feature in the shifter is gummed up and doesn't back up fast enough. I have only experience with Campy 9 and 10 speed shifters with this. I don't know how it works in a 11 and 12 sp shifter.

Adjustment of the limit screws is not in this equation.
A RD in an indexed system should be a matter of 5 minutes.


A nice drawing, but the interpretation is incomplete. Your drawing
appears to tell your friend how to synchronize the lever clicks with the
cogs - that is, adjust mid-range shifting. You don't deal with the
extreme positions, i.e. Tom's "overshifting."

You show no limit screws or other hard limits on the rear derailleur.
You also show no hard limits on the motion of the shift lever. So, in
your drawing, what happens if the user moves the shift lever clockwise,
past the last detent notch?

Answer: It would pull the derailleur past the largest cog, toward the
spokes. It would "overshift." For that reason, derailleurs have limit
screws. Or at least, every one I've worked on has had them.

If the limit screws have no function, why are they there?

It's true, of course, that those screws have nothing to do with
mid-range shifting. That's a cable [housing] length adjustment, and
perhaps a B screw adjustment (or your other diagnostic tips) for some
tougher cases.

It sounds like Tom tried to cure overshifting by adjusting the housing
length, thus making his mid-range shifting wonky. If he was
overshifting, he should have tightened a limit screw.

And of course, being Usenet, we may be conflating three different
problems. That's a frequent problem here.

--
- Frank Krygowski
Ads
  #12  
Old June 15th 21, 07:57 PM posted to rec.bicycles.tech
Lou Holtman[_5_]
external usenet poster
 
Posts: 826
Default More Shifting Problems

On Tuesday, June 15, 2021 at 8:24:58 PM UTC+2, Frank Krygowski wrote:
On 6/15/2021 1:29 PM, Lou Holtman wrote:
On Tuesday, June 15, 2021 at 5:37:08 PM UTC+2, Frank Krygowski wrote:
On 6/15/2021 10:42 AM, Tom Kunich wrote:
On Monday, June 14, 2021 at 7:08:25 PM UTC-7, Frank Krygowski wrote:
On 6/14/2021 3:12 PM, Tom Kunich wrote:
On Monday, June 14, 2021 at 8:55:36 AM UTC-7, jbeattie wrote:

Your limit screw should not have any effect on the shifting in the middle of the cassette. Your problems sound like cable tension or a bent derailleur hanger or worn cogs in the middle of your cassette. Whether your derailleur pulleys have bearings or bushings isn't going to make any difference, although worn teeth may affect shifting.

Where did I say anything at all about the limit screw having anything to do with anything but to keep a derailleur from overshifting? While out on a ride I overshifted the rear derailleur. I caught it before there was any damage to the wheel but I did not want to overshift again so I readjusted the rear derailleur tension so that it would not overshift. That unfortunately screwed up the shifting so I had to ride in gears that were not effected.

Don't tell me you wouldn't do the same thing if you didn't have a screwdriver of the proper size to reset the limit screw.
Despite your long history of mechanical mishaps, you really went on a
bike ride with no tool capable of adjusting a tiny screw?

Why?? To save weight??

There is a reason that I was successful and you were a nothing that did nothing - I had the sense to know that simply turning an adjustment screw would get me back 10 miles where I could properly adjust things. People like you stop and block roads until cars get tired of your stupid bull****.
No, people like me turn the proper screw and ride on.

It sounds like you messed with cable length adjustment, screwing up your
shifting, when you should have messed with the limit screw and left your
shift levers in synch with your cog spacing.

Again: You should consider keeping your mistakes secret. You continually
tell us about your incompetence.


--
- Frank Krygowski



Again limit screws have nothing to do with the adjustment of your RD. I once explained that to a friend with a simple drawing:

https://photos.app.goo.gl/xT6x8vfz4hRwx9Y9A

If the chain is jumping between gears than:
- RD is not adjusted right,
- bent RD hanger,
- upper pulley wheel has to much radial play causing hysteresis which makes adjustment near impossible,
- B screw adjustment way off,
- outer plate of a chain link displaced,
- wrong cassette,
- the overshift feature in the shifter is gummed up and doesn't back up fast enough. I have only experience with Campy 9 and 10 speed shifters with this. I don't know how it works in a 11 and 12 sp shifter.

Adjustment of the limit screws is not in this equation.
A RD in an indexed system should be a matter of 5 minutes.

A nice drawing, but the interpretation is incomplete. Your drawing
appears to tell your friend how to synchronize the lever clicks with the
cogs - that is, adjust mid-range shifting. You don't deal with the
extreme positions, i.e. Tom's "overshifting."

You show no limit screws or other hard limits on the rear derailleur.
You also show no hard limits on the motion of the shift lever. So, in
your drawing, what happens if the user moves the shift lever clockwise,
past the last detent notch?

Answer: It would pull the derailleur past the largest cog, toward the
spokes. It would "overshift." For that reason, derailleurs have limit
screws. Or at least, every one I've worked on has had them.

If the limit screws have no function, why are they there?

It's true, of course, that those screws have nothing to do with
mid-range shifting. That's a cable [housing] length adjustment, and
perhaps a B screw adjustment (or your other diagnostic tips) for some
tougher cases.

It sounds like Tom tried to cure overshifting by adjusting the housing
length, thus making his mid-range shifting wonky. If he was
overshifting, he should have tightened a limit screw.

And of course, being Usenet, we may be conflating three different
problems. That's a frequent problem here.



I don't say limit screws have no function but they don't have anything to do with the adjustment of the RD. They are a safety thing in case someone tries to do shift beyond the largest cog.

Lou
  #13  
Old June 15th 21, 08:31 PM posted to rec.bicycles.tech
Sir Ridesalot
external usenet poster
 
Posts: 5,270
Default More Shifting Problems

On Tuesday, June 15, 2021 at 2:57:14 p.m. UTC-4, wrote:
On Tuesday, June 15, 2021 at 8:24:58 PM UTC+2, Frank Krygowski wrote:
On 6/15/2021 1:29 PM, Lou Holtman wrote:
On Tuesday, June 15, 2021 at 5:37:08 PM UTC+2, Frank Krygowski wrote:
On 6/15/2021 10:42 AM, Tom Kunich wrote:
On Monday, June 14, 2021 at 7:08:25 PM UTC-7, Frank Krygowski wrote:
On 6/14/2021 3:12 PM, Tom Kunich wrote:
On Monday, June 14, 2021 at 8:55:36 AM UTC-7, jbeattie wrote:

Your limit screw should not have any effect on the shifting in the middle of the cassette. Your problems sound like cable tension or a bent derailleur hanger or worn cogs in the middle of your cassette. Whether your derailleur pulleys have bearings or bushings isn't going to make any difference, although worn teeth may affect shifting.

Where did I say anything at all about the limit screw having anything to do with anything but to keep a derailleur from overshifting? While out on a ride I overshifted the rear derailleur. I caught it before there was any damage to the wheel but I did not want to overshift again so I readjusted the rear derailleur tension so that it would not overshift. That unfortunately screwed up the shifting so I had to ride in gears that were not effected.

Don't tell me you wouldn't do the same thing if you didn't have a screwdriver of the proper size to reset the limit screw.
Despite your long history of mechanical mishaps, you really went on a
bike ride with no tool capable of adjusting a tiny screw?

Why?? To save weight??

There is a reason that I was successful and you were a nothing that did nothing - I had the sense to know that simply turning an adjustment screw would get me back 10 miles where I could properly adjust things. People like you stop and block roads until cars get tired of your stupid bull****..
No, people like me turn the proper screw and ride on.

It sounds like you messed with cable length adjustment, screwing up your
shifting, when you should have messed with the limit screw and left your
shift levers in synch with your cog spacing.

Again: You should consider keeping your mistakes secret. You continually
tell us about your incompetence.


--
- Frank Krygowski


Again limit screws have nothing to do with the adjustment of your RD. I once explained that to a friend with a simple drawing:

https://photos.app.goo.gl/xT6x8vfz4hRwx9Y9A

If the chain is jumping between gears than:
- RD is not adjusted right,
- bent RD hanger,
- upper pulley wheel has to much radial play causing hysteresis which makes adjustment near impossible,
- B screw adjustment way off,
- outer plate of a chain link displaced,
- wrong cassette,
- the overshift feature in the shifter is gummed up and doesn't back up fast enough. I have only experience with Campy 9 and 10 speed shifters with this. I don't know how it works in a 11 and 12 sp shifter.

Adjustment of the limit screws is not in this equation.
A RD in an indexed system should be a matter of 5 minutes.

A nice drawing, but the interpretation is incomplete. Your drawing
appears to tell your friend how to synchronize the lever clicks with the
cogs - that is, adjust mid-range shifting. You don't deal with the
extreme positions, i.e. Tom's "overshifting."

You show no limit screws or other hard limits on the rear derailleur.
You also show no hard limits on the motion of the shift lever. So, in
your drawing, what happens if the user moves the shift lever clockwise,
past the last detent notch?

Answer: It would pull the derailleur past the largest cog, toward the
spokes. It would "overshift." For that reason, derailleurs have limit
screws. Or at least, every one I've worked on has had them.

If the limit screws have no function, why are they there?

It's true, of course, that those screws have nothing to do with
mid-range shifting. That's a cable [housing] length adjustment, and
perhaps a B screw adjustment (or your other diagnostic tips) for some
tougher cases.

It sounds like Tom tried to cure overshifting by adjusting the housing
length, thus making his mid-range shifting wonky. If he was
overshifting, he should have tightened a limit screw.

And of course, being Usenet, we may be conflating three different
problems. That's a frequent problem here.

I don't say limit screws have no function but they don't have anything to do with the adjustment of the RD. They are a safety thing in case someone tries to do shift beyond the largest cog.

Lou


Ah but Tom's original post was about his FRONT derailleur.

Cheers
  #14  
Old June 15th 21, 09:50 PM posted to rec.bicycles.tech
Tom Kunich[_4_]
external usenet poster
 
Posts: 2,196
Default More Shifting Problems

On Tuesday, June 15, 2021 at 10:30:00 AM UTC-7, wrote:
On Tuesday, June 15, 2021 at 5:37:08 PM UTC+2, Frank Krygowski wrote:
On 6/15/2021 10:42 AM, Tom Kunich wrote:
On Monday, June 14, 2021 at 7:08:25 PM UTC-7, Frank Krygowski wrote:
On 6/14/2021 3:12 PM, Tom Kunich wrote:
On Monday, June 14, 2021 at 8:55:36 AM UTC-7, jbeattie wrote:

Your limit screw should not have any effect on the shifting in the middle of the cassette. Your problems sound like cable tension or a bent derailleur hanger or worn cogs in the middle of your cassette. Whether your derailleur pulleys have bearings or bushings isn't going to make any difference, although worn teeth may affect shifting.

Where did I say anything at all about the limit screw having anything to do with anything but to keep a derailleur from overshifting? While out on a ride I overshifted the rear derailleur. I caught it before there was any damage to the wheel but I did not want to overshift again so I readjusted the rear derailleur tension so that it would not overshift. That unfortunately screwed up the shifting so I had to ride in gears that were not effected.

Don't tell me you wouldn't do the same thing if you didn't have a screwdriver of the proper size to reset the limit screw.
Despite your long history of mechanical mishaps, you really went on a
bike ride with no tool capable of adjusting a tiny screw?

Why?? To save weight??

There is a reason that I was successful and you were a nothing that did nothing - I had the sense to know that simply turning an adjustment screw would get me back 10 miles where I could properly adjust things. People like you stop and block roads until cars get tired of your stupid bull****.

No, people like me turn the proper screw and ride on.

It sounds like you messed with cable length adjustment, screwing up your
shifting, when you should have messed with the limit screw and left your
shift levers in synch with your cog spacing.

Again: You should consider keeping your mistakes secret. You continually
tell us about your incompetence.


--
- Frank Krygowski

Again limit screws have nothing to do with the adjustment of your RD. I once explained that to a friend with a simple drawing:

https://photos.app.goo.gl/xT6x8vfz4hRwx9Y9A

If the chain is jumping between gears than:
- RD is not adjusted right,
- bent RD hanger,
- upper pulley wheel has to much radial play causing hysteresis which makes adjustment near impossible,
- B screw adjustment way off,
- outer plate of a chain link displaced,
- wrong cassette,
- the overshift feature in the shifter is gummed up and doesn't back up fast enough. I have only experience with Campy 9 and 10 speed shifters with this. I don't know how it works in a 11 and 12 sp shifter.

Adjustment of the limit screws is not in this equation.
A RD in an indexed system should be a matter of 5 minutes.

Lou, every shifter will push further than a position without shifting. They are purposely designed that way so that if cable stretch allows you to not quite shift you can push it a little more without going into a higher gear but it will lift that slight amount. EVERY manual shifter is designed that way. Even the old SIS downtube shifters acted in exactly the same manner.

What this means is that you MUST set the upper and lower limit screws What this does, is to allow you to keep cable stretch from undershifting off of the bottom of the small cog. And it allows you to lift the chain slightly up into the higher gear that you cannot quite reach. So, if you don't have the upper limit screw set you CAN shift off of the top of the cogset and over into the spokes.

That cable stretch happens is shown by team mechanics leaning out of the team car and readjusting the cable.

I really don't quite get what you mean when you say that the limit screws aren't even needed.
  #15  
Old June 15th 21, 10:19 PM posted to rec.bicycles.tech
Lou Holtman[_5_]
external usenet poster
 
Posts: 826
Default More Shifting Problems

On Tuesday, June 15, 2021 at 10:51:00 PM UTC+2, wrote:
On Tuesday, June 15, 2021 at 10:30:00 AM UTC-7, wrote:
On Tuesday, June 15, 2021 at 5:37:08 PM UTC+2, Frank Krygowski wrote:
On 6/15/2021 10:42 AM, Tom Kunich wrote:
On Monday, June 14, 2021 at 7:08:25 PM UTC-7, Frank Krygowski wrote:
On 6/14/2021 3:12 PM, Tom Kunich wrote:
On Monday, June 14, 2021 at 8:55:36 AM UTC-7, jbeattie wrote:

Your limit screw should not have any effect on the shifting in the middle of the cassette. Your problems sound like cable tension or a bent derailleur hanger or worn cogs in the middle of your cassette. Whether your derailleur pulleys have bearings or bushings isn't going to make any difference, although worn teeth may affect shifting.

Where did I say anything at all about the limit screw having anything to do with anything but to keep a derailleur from overshifting? While out on a ride I overshifted the rear derailleur. I caught it before there was any damage to the wheel but I did not want to overshift again so I readjusted the rear derailleur tension so that it would not overshift. That unfortunately screwed up the shifting so I had to ride in gears that were not effected.

Don't tell me you wouldn't do the same thing if you didn't have a screwdriver of the proper size to reset the limit screw.
Despite your long history of mechanical mishaps, you really went on a
bike ride with no tool capable of adjusting a tiny screw?

Why?? To save weight??

There is a reason that I was successful and you were a nothing that did nothing - I had the sense to know that simply turning an adjustment screw would get me back 10 miles where I could properly adjust things. People like you stop and block roads until cars get tired of your stupid bull****..
No, people like me turn the proper screw and ride on.

It sounds like you messed with cable length adjustment, screwing up your
shifting, when you should have messed with the limit screw and left your
shift levers in synch with your cog spacing.

Again: You should consider keeping your mistakes secret. You continually
tell us about your incompetence.


--
- Frank Krygowski

Again limit screws have nothing to do with the adjustment of your RD. I once explained that to a friend with a simple drawing:

https://photos.app.goo.gl/xT6x8vfz4hRwx9Y9A

If the chain is jumping between gears than:
- RD is not adjusted right,
- bent RD hanger,
- upper pulley wheel has to much radial play causing hysteresis which makes adjustment near impossible,
- B screw adjustment way off,
- outer plate of a chain link displaced,
- wrong cassette,
- the overshift feature in the shifter is gummed up and doesn't back up fast enough. I have only experience with Campy 9 and 10 speed shifters with this. I don't know how it works in a 11 and 12 sp shifter.

Adjustment of the limit screws is not in this equation.
A RD in an indexed system should be a matter of 5 minutes.

Lou, every shifter will push further than a position without shifting. They are purposely designed that way so that if cable stretch allows you to not quite shift you can push it a little more without going into a higher gear but it will lift that slight amount. EVERY manual shifter is designed that way. Even the old SIS downtube shifters acted in exactly the same manner..

What this means is that you MUST set the upper and lower limit screws What this does, is to allow you to keep cable stretch from undershifting off of the bottom of the small cog. And it allows you to lift the chain slightly up into the higher gear that you cannot quite reach. So, if you don't have the upper limit screw set you CAN shift off of the top of the cogset and over into the spokes.

That cable stretch happens is shown by team mechanics leaning out of the team car and readjusting the cable.

I really don't quite get what you mean when you say that the limit screws aren't even needed.


Tom I really don't understand what you trying to say, but I am sure that on my one bike with mechanical shifting (Campy Super Record 11 speed) which is perfectly adjusted I can back off the limit screws without disaster to happen especially the upper limit screw (preventing the chain from dropping off the small cog) because after shifting to the smallest cog the RD spring will back it off from the limit screw. Back off the lower limit screw (largest cog) is not wise because on a hard climb and already in the lowest gear a lot of people hope they still have a lower gear and try to force the RD further towards the spokes. Like I said it is a (valuable) safety thing. Theoretically you don't need no limit screws with a perfectly adjusted RD and don't do something like forcing the RD towards a lower gear when you already in the lowest gear. Overshift is built in the shifter mechanism shifting to a lower gear and will happen also when you move the shifter just to the click. The RD backs off a bit when you release the shifter. You can see this very clearly on your Di2 setups every time you shift to a lower gear you see a little overshift and after a half a second or so backing off a bit. You can hear this. I'm done now.

Lou
  #16  
Old June 15th 21, 10:30 PM posted to rec.bicycles.tech
Tom Kunich[_4_]
external usenet poster
 
Posts: 2,196
Default More Shifting Problems

On Tuesday, June 15, 2021 at 11:07:19 AM UTC-7, jbeattie wrote:
On Tuesday, June 15, 2021 at 10:30:00 AM UTC-7, wrote:
On Tuesday, June 15, 2021 at 5:37:08 PM UTC+2, Frank Krygowski wrote:
On 6/15/2021 10:42 AM, Tom Kunich wrote:
On Monday, June 14, 2021 at 7:08:25 PM UTC-7, Frank Krygowski wrote:
On 6/14/2021 3:12 PM, Tom Kunich wrote:
On Monday, June 14, 2021 at 8:55:36 AM UTC-7, jbeattie wrote:

Your limit screw should not have any effect on the shifting in the middle of the cassette. Your problems sound like cable tension or a bent derailleur hanger or worn cogs in the middle of your cassette. Whether your derailleur pulleys have bearings or bushings isn't going to make any difference, although worn teeth may affect shifting.

Where did I say anything at all about the limit screw having anything to do with anything but to keep a derailleur from overshifting? While out on a ride I overshifted the rear derailleur. I caught it before there was any damage to the wheel but I did not want to overshift again so I readjusted the rear derailleur tension so that it would not overshift. That unfortunately screwed up the shifting so I had to ride in gears that were not effected.

Don't tell me you wouldn't do the same thing if you didn't have a screwdriver of the proper size to reset the limit screw.
Despite your long history of mechanical mishaps, you really went on a
bike ride with no tool capable of adjusting a tiny screw?

Why?? To save weight??

There is a reason that I was successful and you were a nothing that did nothing - I had the sense to know that simply turning an adjustment screw would get me back 10 miles where I could properly adjust things. People like you stop and block roads until cars get tired of your stupid bull****..
No, people like me turn the proper screw and ride on.

It sounds like you messed with cable length adjustment, screwing up your
shifting, when you should have messed with the limit screw and left your
shift levers in synch with your cog spacing.

Again: You should consider keeping your mistakes secret. You continually
tell us about your incompetence.


--
- Frank Krygowski

Again limit screws have nothing to do with the adjustment of your RD. I once explained that to a friend with a simple drawing:

https://photos.app.goo.gl/xT6x8vfz4hRwx9Y9A

If the chain is jumping between gears than:
- RD is not adjusted right,
- bent RD hanger,
- upper pulley wheel has to much radial play causing hysteresis which makes adjustment near impossible,
- B screw adjustment way off,
- outer plate of a chain link displaced,
- wrong cassette,
- the overshift feature in the shifter is gummed up and doesn't back up fast enough. I have only experience with Campy 9 and 10 speed shifters with this. I don't know how it works in a 11 and 12 sp shifter.

Adjustment of the limit screws is not in this equation.
A RD in an indexed system should be a matter of 5 minutes.

As I understand it, he almost put his chain into the spokes shifting into the big cog. Rather than screwing-in his low gear limit screw (because he didn't have a pocket tool, apparently), he de-tensioned the cable, which (as one would expect) screwed up his shifting.

I think he tried to correct this at home, and it didn't work. It still shifted poorly. If he was putting his derailleur into the spokes, I wouldn't be surprised if he had a bent hanger.


Different bikes but what actually happened was that I installed an off-the-shelf rear derailleur and I expect I only set the lower limit. The upper limit screw was two full turns out of adjustment. Shifting EASY acted fine like Lou is trying to imply. But hitting a steep hill and having to shift pretty hard halfway up that 11%. It just pushed right over the large cog. Because the hill was so steep as soon as power came off the bike stopped. So no damage. But I assumed that the limit screw was just set a little off and loosened the cable a little. This worked fine except I would have to slightly overshift to get the middle gears to shift. And I was more careful to shift into low.

The bike that had the derailleur stop explode was the Douglas Vector and that did bend the hanger. But I bought a new one and got a new stop fitting for that derailleur. They sent me an aluminum fitting which was funny because ALL of the Campy 11 speed line use the steel fitting that is identical to the one that broke on my Centaur derailleur. That aluminum fitting looks like the Mirage fitting but they are not interchangeable. But all of the steel fittings are interchangeable.

In any case, the problem isn't quite fixed since I have to install one of the ball bearing idler pulley's so that it doesn't wobble and keep it from jumping a cog in ONE spot that is adjustable with the cable tension. The shifting problem is on the Eddy Merckx Elite which has a VERY heavy derailleur hanger instead of a replaceable one.
  #17  
Old June 15th 21, 10:45 PM posted to rec.bicycles.tech
Tom Kunich[_4_]
external usenet poster
 
Posts: 2,196
Default More Shifting Problems

On Tuesday, June 15, 2021 at 2:19:53 PM UTC-7, wrote:
On Tuesday, June 15, 2021 at 10:51:00 PM UTC+2, wrote:
On Tuesday, June 15, 2021 at 10:30:00 AM UTC-7, wrote:
On Tuesday, June 15, 2021 at 5:37:08 PM UTC+2, Frank Krygowski wrote:
On 6/15/2021 10:42 AM, Tom Kunich wrote:
On Monday, June 14, 2021 at 7:08:25 PM UTC-7, Frank Krygowski wrote:
On 6/14/2021 3:12 PM, Tom Kunich wrote:
On Monday, June 14, 2021 at 8:55:36 AM UTC-7, jbeattie wrote:

Your limit screw should not have any effect on the shifting in the middle of the cassette. Your problems sound like cable tension or a bent derailleur hanger or worn cogs in the middle of your cassette. Whether your derailleur pulleys have bearings or bushings isn't going to make any difference, although worn teeth may affect shifting.

Where did I say anything at all about the limit screw having anything to do with anything but to keep a derailleur from overshifting? While out on a ride I overshifted the rear derailleur. I caught it before there was any damage to the wheel but I did not want to overshift again so I readjusted the rear derailleur tension so that it would not overshift. That unfortunately screwed up the shifting so I had to ride in gears that were not effected.

Don't tell me you wouldn't do the same thing if you didn't have a screwdriver of the proper size to reset the limit screw.
Despite your long history of mechanical mishaps, you really went on a
bike ride with no tool capable of adjusting a tiny screw?

Why?? To save weight??

There is a reason that I was successful and you were a nothing that did nothing - I had the sense to know that simply turning an adjustment screw would get me back 10 miles where I could properly adjust things. People like you stop and block roads until cars get tired of your stupid bull****.
No, people like me turn the proper screw and ride on.

It sounds like you messed with cable length adjustment, screwing up your
shifting, when you should have messed with the limit screw and left your
shift levers in synch with your cog spacing.

Again: You should consider keeping your mistakes secret. You continually
tell us about your incompetence.


--
- Frank Krygowski
Again limit screws have nothing to do with the adjustment of your RD. I once explained that to a friend with a simple drawing:

https://photos.app.goo.gl/xT6x8vfz4hRwx9Y9A

If the chain is jumping between gears than:
- RD is not adjusted right,
- bent RD hanger,
- upper pulley wheel has to much radial play causing hysteresis which makes adjustment near impossible,
- B screw adjustment way off,
- outer plate of a chain link displaced,
- wrong cassette,
- the overshift feature in the shifter is gummed up and doesn't back up fast enough. I have only experience with Campy 9 and 10 speed shifters with this. I don't know how it works in a 11 and 12 sp shifter.

Adjustment of the limit screws is not in this equation.
A RD in an indexed system should be a matter of 5 minutes.

Lou, every shifter will push further than a position without shifting. They are purposely designed that way so that if cable stretch allows you to not quite shift you can push it a little more without going into a higher gear but it will lift that slight amount. EVERY manual shifter is designed that way. Even the old SIS downtube shifters acted in exactly the same manner.

What this means is that you MUST set the upper and lower limit screws What this does, is to allow you to keep cable stretch from undershifting off of the bottom of the small cog. And it allows you to lift the chain slightly up into the higher gear that you cannot quite reach. So, if you don't have the upper limit screw set you CAN shift off of the top of the cogset and over into the spokes.

That cable stretch happens is shown by team mechanics leaning out of the team car and readjusting the cable.

I really don't quite get what you mean when you say that the limit screws aren't even needed.

Tom I really don't understand what you trying to say, but I am sure that on my one bike with mechanical shifting (Campy Super Record 11 speed) which is perfectly adjusted I can back off the limit screws without disaster to happen especially the upper limit screw (preventing the chain from dropping off the small cog) because after shifting to the smallest cog the RD spring will back it off from the limit screw. Back off the lower limit screw (largest cog) is not wise because on a hard climb and already in the lowest gear a lot of people hope they still have a lower gear and try to force the RD further towards the spokes. Like I said it is a (valuable) safety thing. Theoretically you don't need no limit screws with a perfectly adjusted RD and don't do something like forcing the RD towards a lower gear when you already in the lowest gear. Overshift is built in the shifter mechanism shifting to a lower gear and will happen also when you move the shifter just to the click. The RD backs off a bit when you release the shifter. You can see this very clearly on your Di2 setups every time you shift to a lower gear you see a little overshift and after a half a second or so backing off a bit.. You can hear this. I'm done now.


And where we seem to be disagreeing is that if you shift carefully, yes, you could have the limit screws not set correctly and it would have no effect on the shifting. But if they are set incorrectly and you are under duress and shift hard, you can shift over the top of the large cog. So a fast correction is to slightly loosen the cable tension and then trying to overshift simply puts you into the proper gear. One of the problems doing this is that the middle of the cogs then shift incorrectly.

I'm not sure that you would run into this problem with a Campy 11 speed since they completely redesigned the rear derailleur and it has a different arc - it is much flatter than the 10 speed. It is a better design. The 10 speed was a modified 8 speed and was entirely at its limit with 10 speeds.
  #18  
Old June 15th 21, 10:52 PM posted to rec.bicycles.tech
Tom Kunich[_4_]
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On Tuesday, June 15, 2021 at 12:31:20 PM UTC-7, Sir Ridesalot wrote:
On Tuesday, June 15, 2021 at 2:57:14 p.m. UTC-4, wrote:
On Tuesday, June 15, 2021 at 8:24:58 PM UTC+2, Frank Krygowski wrote:
On 6/15/2021 1:29 PM, Lou Holtman wrote:
On Tuesday, June 15, 2021 at 5:37:08 PM UTC+2, Frank Krygowski wrote:
On 6/15/2021 10:42 AM, Tom Kunich wrote:
On Monday, June 14, 2021 at 7:08:25 PM UTC-7, Frank Krygowski wrote:
On 6/14/2021 3:12 PM, Tom Kunich wrote:
On Monday, June 14, 2021 at 8:55:36 AM UTC-7, jbeattie wrote:

Your limit screw should not have any effect on the shifting in the middle of the cassette. Your problems sound like cable tension or a bent derailleur hanger or worn cogs in the middle of your cassette. Whether your derailleur pulleys have bearings or bushings isn't going to make any difference, although worn teeth may affect shifting.

Where did I say anything at all about the limit screw having anything to do with anything but to keep a derailleur from overshifting? While out on a ride I overshifted the rear derailleur. I caught it before there was any damage to the wheel but I did not want to overshift again so I readjusted the rear derailleur tension so that it would not overshift. That unfortunately screwed up the shifting so I had to ride in gears that were not effected.

Don't tell me you wouldn't do the same thing if you didn't have a screwdriver of the proper size to reset the limit screw.
Despite your long history of mechanical mishaps, you really went on a
bike ride with no tool capable of adjusting a tiny screw?

Why?? To save weight??

There is a reason that I was successful and you were a nothing that did nothing - I had the sense to know that simply turning an adjustment screw would get me back 10 miles where I could properly adjust things. People like you stop and block roads until cars get tired of your stupid bull****.
No, people like me turn the proper screw and ride on.

It sounds like you messed with cable length adjustment, screwing up your
shifting, when you should have messed with the limit screw and left your
shift levers in synch with your cog spacing.

Again: You should consider keeping your mistakes secret. You continually
tell us about your incompetence.


--
- Frank Krygowski


Again limit screws have nothing to do with the adjustment of your RD. I once explained that to a friend with a simple drawing:

https://photos.app.goo.gl/xT6x8vfz4hRwx9Y9A

If the chain is jumping between gears than:
- RD is not adjusted right,
- bent RD hanger,
- upper pulley wheel has to much radial play causing hysteresis which makes adjustment near impossible,
- B screw adjustment way off,
- outer plate of a chain link displaced,
- wrong cassette,
- the overshift feature in the shifter is gummed up and doesn't back up fast enough. I have only experience with Campy 9 and 10 speed shifters with this. I don't know how it works in a 11 and 12 sp shifter.

Adjustment of the limit screws is not in this equation.
A RD in an indexed system should be a matter of 5 minutes.
A nice drawing, but the interpretation is incomplete. Your drawing
appears to tell your friend how to synchronize the lever clicks with the
cogs - that is, adjust mid-range shifting. You don't deal with the
extreme positions, i.e. Tom's "overshifting."

You show no limit screws or other hard limits on the rear derailleur.
You also show no hard limits on the motion of the shift lever. So, in
your drawing, what happens if the user moves the shift lever clockwise,
past the last detent notch?

Answer: It would pull the derailleur past the largest cog, toward the
spokes. It would "overshift." For that reason, derailleurs have limit
screws. Or at least, every one I've worked on has had them.

If the limit screws have no function, why are they there?

It's true, of course, that those screws have nothing to do with
mid-range shifting. That's a cable [housing] length adjustment, and
perhaps a B screw adjustment (or your other diagnostic tips) for some
tougher cases.

It sounds like Tom tried to cure overshifting by adjusting the housing
length, thus making his mid-range shifting wonky. If he was
overshifting, he should have tightened a limit screw.

And of course, being Usenet, we may be conflating three different
problems. That's a frequent problem here.

I don't say limit screws have no function but they don't have anything to do with the adjustment of the RD. They are a safety thing in case someone tries to do shift beyond the largest cog.

Lou

Ah but Tom's original post was about his FRONT derailleur.

Cheers

I was asking how long it should take to adjust the front derailleur to operate with the rear derailleur noiselessly. This is quite difficult to get without throwing the chain over the top of the big ring. The adjustment of the front derailleur has to be exactly correct in fore and aft and height adjustments. I spent about a half hour to get it correct and pro mechanics must have some easy way of doing this. But the result was that I must have missed setting the inner limit screw on the rear derailleur.
  #19  
Old June 15th 21, 10:56 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
Default More Shifting Problems

On 6/15/2021 5:30 PM, Tom Kunich wrote:
On Tuesday, June 15, 2021 at 11:07:19 AM UTC-7, jbeattie wrote:

I think he tried to correct this at home, and it didn't work. It still shifted poorly. If he was putting his derailleur into the spokes, I wouldn't be surprised if he had a bent hanger.


Different bikes but what actually happened was that I installed an off-the-shelf rear derailleur and I expect I only set the lower limit. The upper limit screw was two full turns out of adjustment. Shifting EASY acted fine like Lou is trying to imply. But hitting a steep hill and having to shift pretty hard halfway up that 11%. It just pushed right over the large cog. Because the hill was so steep as soon as power came off the bike stopped. So no damage. But I assumed that the limit screw was just set a little off and loosened the cable a little. This worked fine except I would have to slightly overshift to get the middle gears to shift. And I was more careful to shift into low.


Yes. And I would have tightened the derailleur's low gear limit screw,
instead of loosening the cable. Shifting would have remained just as
good as before in the middle gears.

--
- Frank Krygowski
  #20  
Old June 15th 21, 10:58 PM posted to rec.bicycles.tech
Frank Krygowski[_4_]
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Posts: 10,538
Default More Shifting Problems

On 6/15/2021 5:52 PM, Tom Kunich wrote:

I was asking how long it should take to adjust the front derailleur to operate with the rear derailleur noiselessly. This is quite difficult to get without throwing the chain over the top of the big ring. The adjustment of the front derailleur has to be exactly correct in fore and aft and height adjustments. I spent about a half hour to get it correct and pro mechanics must have some easy way of doing this. But the result was that I must have missed setting the inner limit screw on the rear derailleur.


I'll agree with Tom, in that I have sometimes found it tricky to
precisely set up a front derailluer.

--
- Frank Krygowski
 




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