chorus or dura-ace/ultegra?

[531Aussie]

The shifting problem DOES exist on non-DA, 8-and-9-speed Shimano shifters [presumably, with the 10-speed Ultegra-and-below shifters since supposedly the design did not change] when going uphill & attempting to shift while the drivetrain is actually under load (vs. unloaded) ...

Maybe your frame flexes so much under load that the cable is effectively shortening just enough for the gears to jump

 

[alfeng]

Maybe your frame flexes so much under load that the cable is effectively shortening just enough for the gears to jump

That's an interesting suggestion and would be a good insight ...

But, I have never had a problem with ERGO shifters under the same, presumably-high loads with the same/(various) frames ... other than not having a larger cog to shift on to.

BUT, I suppose it could be suggested that some of those loads to which I have alluded are somehow higher than those which some others who use Shimano have encountered ... or, not!?!

 

[dhk2]

alfeng, surprising to me that you doubt Shimano knows just as well as Campagnolo how to make cogs and chains which shift under load. Do you actually believe Campy uses some "secret technology" that allows them to do something that Shimano can't? If they in fact had any design advantage, don't you think Shimano would have found a way to copy it by now?

 

[alfeng]

alfeng, surprising to me that you doubt Shimano knows just as well as Campagnolo how to make cogs and chains which shift under load. Do you actually believe Campy uses some "secret technology" that allows them to do something that Shimano can't? If they in fact had any design advantage, don't you think Shimano would have found a way to copy it by now?

NEWS FLASH! The superior chainring & cog design developed by Shimano (i.e., ramping and/or pinning) are a direct consequence of the dodgy shifting of their inferior STI shifter design ...

The original STI design is one reason that the pre-7900 -shifters are so large (by comparison to Campagnolo & SRAM) & the shifting mechanism has so many "moving parts" AND probably the driving force behind Shimano's ever-evolving ramping-and-pinning development.

The development of the new (CN-7900?) chain design can be attributed as an attempt to further mitigate the effects of the in-built "dwell" which the Shimano shifters have been saddled with through their original design.

As I've stated many times before, I 'love' Shimano -- I think that Shimano's CUSTOMER SERVICE in North America is excellent and, other than their pre-7900 shifters, I think that Shimano's ROAD products are generally superior.

FYI. There is nothing secret about the Campagnolo design which makes it work better ... rather, the Shimano engineer(s) who first worked on the original STI design went out of his/her/their way to unintentionally make the shifter dodgy because someone in the design team must have embraced the notion of "dwell" facilitating the shifting process.

Supposedly, SRAM does not suffer from downshifting problems ... and, I would suggest that it is because the SRAM engineers did not incorporate "dwell" in their shift mechanism.

I would speculate that the reason Shimano has been slow to abandon the original STI design is a consequence of bean counters & lawyers who are "protecting" the STI design patents ...

Besides, if the majority of people were/have-been/are willing to buy the emperor's-new-clothes, why change it?

Campagnolo & SRAM (et al) have benefitted greatly from Shimano NOT enforcing their patent rights with regard to ramping & pinning, BTW.

So, the truth of the matter is that Shimano has designed better chainrings, cogs, and (now) chains than anyone else.

FWIW. After deducing that Campagnolo shifters were superior in heavy downshifting situations, I further tested their capability by installing an older NON-ramped/pinned (e.g., 7-/8-speed) chainring on one of my cranks -- subjectively, I would say that the shifting onto a larger ring with the Campagnolo shifter was-and-is superior to the shifting with Shimano shifters WITH ramped-and-pinned chainrings (even than with Shimano chainrings) -- I have never experienced any shifting hesitation with any of the older/thinner, un-ramped/pinned chainrings with the Campagnolo Ergo shifters ...

I doubt (m)any STI users would be willing to use the an 8-or-9-speed chainring with their 10-speed STI shifters -- or, an 8-speed-or-earlier chainring with their 9-or-10 speed STI shifters -- if they have a choice.

The development of the stiffer 7900 chainring is undoubtedly a further attempt to overcome the in-built "dwell" of earlier shifters (and possibly, the 7900 since I recall reading that Shimano indicated that there wasn't a change in the mechanical design other than re-routing the derailleur cable).

Shimano shifters DO work well in most circumstances when mated with other Shimano components ... they just don't work as flawlessly as Campagnolo shifters in all circumstances.

 

[Dietmar]

Just two quick questions on this:

- I assume when you guys talk about shifting problems under load, you mean shifting on the front derailleur only, right? For the rear derailleur, the shifting process occurs on a part of the chain that is decoupled from the load, so load shouldn't matter for rear derailleur shifting, right?
- The (alleged) issues with Shimano shifting only occur with the STI shifters, not the downtube shifters, right? For the downtube shifters, the shifting motion should be more direct, without any dwell or any other gimmicks.

I'm just curious here; myself, I've been happy to stick with Campagnolo

 

[alfeng]

Just two quick questions on this:

- I assume when you guys talk about shifting problems under load, you mean shifting on the front derailleur only, right? For the rear derailleur, the shifting process occurs on a part of the chain that is decoupled from the load, so load shouldn't matter for rear derailleur shifting, right?
- The (alleged) issues with Shimano shifting only occur with the STI shifters, not the downtube shifters, right? For the downtube shifters, the shifting motion should be more direct, without any dwell or any other gimmicks.

I'm just curious here; myself, I've been happy to stick with Campagnolo

FWIW. I was talking about shifting on the rear, specifically, but I have had SOME shifting problems going to the large ring from the inner with ULTEGRA 6500 shifters at times; so, the improved FRONT shifting which the Campagnolo shifters provide over the Shimano shifters has been a bonus (for me).

I have never had a problem with downtube shifters, friction or indexed (Shimano).

BTW. Sorry about enlarging the FONT SIZE to '4' ... the default size ('3') is tedious to read (for me).

 

[Dietmar]

Hmm, strange... Any idea why there would be a problem shifting the rear derailleur under load? I mean, in theory that rear derailleur, and the piece of chain it works on, should be entirely unaffected by the load. What am I missing here?

 

[dhk2]

Thanks for the news flash. I certainly don't pretend to be up on all the design knowledge you posess, but have trouble finding any fault or "dwell" with my 7700 STI shifters and the FSA triple chainring combo I've been using for the last 22K miles. I do shift a fair amount on the chainrings for the steep rollers here, but as I say don't make a habit of shifting under load. Do recall dropping the chain a couple of times when shifting to the little (30) ring under load, but I just chalk that up to brain-fade at the bottom of a steep climb.

I've only used Campy Record for a week on a "hire bike" in Italy, and found that worked well. It felt different of course, but can't say it was any "better" than Shimano at doing the job.

 

[slowbutnotdead]

I have been riding campy components for 32 years and have never had a problem, maybe I don't ride hard enough, have also used all grade of shimano products. using either brands will provide you with good results. I have a bike that used the chorus group and a carbon fiber bike that uses the record group , both 10 speed and a third bike that is a mix of dura ace and ultegra. They all ride great the shifting is better on the record than the chorus but the chorus has a long cage and the record has a short cage. the dura ace shifts as well almost as well as the record but it is utilizing bar ends on aero bars.

I think that it depends on what you are doing with the bike will direct you to brand of components. if you are making a time trial or tri bike with aero bars then the shimano drive train may be to your choosing. but if you are trying to make a standard road bike with brifters then either campy or shimano would be would be fine. if you are on a budget then why pay for record or dura ace? Chorus and Ultegra are both fine and can be had at much better prices.

As for SRAM, I have never used the Sram equipment and don't have an opinion except that for me the tap and double tap seems strange.

 

[alfeng]

Hmm, strange... Any idea why there would be a problem shifting the rear derailleur under load? I mean, in theory that rear derailleur, and the piece of chain it works on, should be entirely unaffected by the load. What am I missing here?

FWIW. This is just another case where, like battle plans, theory & reality are apparently not in harmony ...

I would suggest, OT, that one reason the MAVIC wheels with their CF spokes failed (quite dramatically in some instances) is because the engineers who did the calculations had bought into the apparent notion that the side-load which a wheel experiences is not consequential to the durability of a wheel ... but, I have digressed too far.

 

[alfeng]

Thanks for the news flash. I certainly don't pretend to be up on all the design knowledge you posess, but have trouble finding any fault or "dwell" with my 7700 STI shifters and the FSA triple chainring combo I've been using for the last 22K miles. I do shift a fair amount on the chainrings for the steep rollers here, but as I say don't make a habit of shifting under load. Do recall dropping the chain a couple of times when shifting to the little (30) ring under load, but I just chalk that up to brain-fade at the bottom of a steep climb.

I've only used Campy Record for a week on a "hire bike" in Italy, and found that worked well. It felt different of course, but can't say it was any "better" than Shimano at doing the job.

Huntsville? NASA?

Gee, I hope the engineers & scientists whom we are paying have more curiosity ... but, perhaps I misinterpret your remarks as being sarcastic when you don't mean them to be.

And, as I have stated, my experience is with non-DA shifters (i.e., the majority of those made by Shimano); so, I am glad that those who use DA shifters who have remarked in this Forum that they don't have a shifting problem (front or rear) do so with such conviction.

 

[dhk2]

Yeah, maybe somewhat sarcastic, but you do come across as having a vast knowledge of how or why Shimano makes design decisions which is hard for me to leave unquestioned.

You're correct that Huntsville is home to NASA Marshall Space Flight Center, as well as Army aviation and missile engineering. I do believe I have the typical curiosity of an engineer; that's why I'm asking all the questions. But I've also developed a degree of skepticism from working in the aerospace field. As you know, times the "technical experts" develop a theory, bias or preference about what a design change or "improvement" will do, only to find out it does nothing, or makes the problem worse.

None of the above is intended to invalidate your experience with the different groups; it's certainly greater than mine which is very limited as I described above.

Bottom line for me is that the issue hasn't triggered my curiosity because I rarely shift under load, front or rear. Just to summarize, when I've tried with rear shifting last week, there was no problem, just more driveline shock than I want to apply to the chain, gearing and rear wheel.

Certainly do have a problem shifting the chainrings under heavy load. When "popping" the FD for a shift down to a smaller ring, either nothing happens or the chain tends to drop to the inside, or I feel resistance and hear noise when pushing in the lever so I quit the attempt and just grind up the hill without the shift.

Suppose we have to define "load" to begin with any clarity, but if Campagnolo can shift the chainrings under any significant load, that would be surprising to me. (note: I do get surprised from time to time Is that in fact what you're stating?

 

[Dietmar]

Suppose we have to define "load" to begin with any clarity, but if Campagnolo can shift the chainrings under any significant load, that would be surprising to me. (note: I do get surprised from time to time Is that in fact what you're stating?

For what it's worth, I was always able to shift chainrings on my Campy drivetrains under load. With my new 11-speed Campy Super Record this even works quite smoothly; the narrower spacing of the rings for the 11-speed groups probably helps.

Nevertheless, along the lines of your experience, I consider this an emergency situation (typically having to drop down to the small ring on a hill in order to be able to "stay alive"), that puts a lot of strain on various drivetrain components. I can barely remember the last time I had to do this, and in any case I am supposed to think ahead, and be on the right ring before the situation develops into an emergency...

 

[dhk2]

Will accept that your Campy chainrings shift better under load than my DA 9-sp/FSA chainring setup since they don't seem to do it well at all. But shifting under normal conditions is smooth, quick and quiet, which is all I expect.

 

[randochap]

Chorus gets my vote.

 

[alfeng]

Suppose we have to define "load" to begin with any clarity, but if Campagnolo can shift the chainrings under any significant load, that would be surprising to me. (note: I do get surprised from time to time Is that in fact what you're stating?

Sorry to resurrect this thread with my belated reply, but I had exposited the answer to your question in POST #44 of this thread:

FWIW. After deducing that Campagnolo shifters were superior in heavy downshifting situations, I further tested their capability by installing an older NON-ramped/pinned (e.g., 7-/8-speed) chainring on one of my cranks -- subjectively, I would say that the shifting onto a larger ring with the Campagnolo shifter was-and-is superior to the shifting with Shimano shifters WITH ramped-and-pinned chainrings (even than with Shimano chainrings) -- I have never experienced any shifting hesitation with any of the older/thinner, un-ramped/pinned chainrings with the Campagnolo Ergo shifters ...

I doubt (m)any STI users would be willing to use the an 8-or-9-speed chainring with their 10-speed STI shifters -- or, an 8-speed-or-earlier chainring with their 9-or-10 speed STI shifters -- if they have a choice.

The development of the stiffer 7900 chainring is undoubtedly a further attempt to overcome the in-built "dwell" of earlier shifters (and possibly, the 7900 since I recall reading that Shimano indicated that there wasn't a change in the mechanical design other than re-routing the derailleur cable).

Shimano shifters DO work well in most circumstances when mated with other Shimano components ... they just don't work as flawlessly as Campagnolo shifters in all circumstances.
​

So, yes, THAT was what I was stating ... I can also upshift to the larger chainring when the drivetrain is under load (e.g., cresting a hill) without any effort.

It's not the Campagnolo chainrings, as you would like to think, it's the shifters; and, I think that you would be very disappointed if you were to mate a Campagnolo crank & chainrings with a set of Shimano shifters.