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Andrew R Stewart 08-05-22 09:08 PM

Measuring 9 Speed Movements
 
This thread is already many years old and others have gone before me here. I have run mixed drivetrains since the mid 1990s and don't want to move on from my many Campy Ergo (second gen pointy hood versions) levers. But stuff changes over the market cycles of nearly 30 years. It's too bad Campy didn't offer big cog compatible rear ders when it was about 9 or 10 speeds back there. I've thought about this for way too many hours while riding and decided to start some real research in cable pull ratios, guide pulley lateral movement per click and how "incompatible" choices can be made to work. I've been running JTek ShiftMates to translate between Shimano and Campy parts of the system for years too.

With the foundation of actual measuring beats reading I finally decided to make some shifter cable pull and resulting der cage lateral travel measurements and do so with some ease of repeating values and swapping out parts. A fixture was called for. Here's what i came up with.
https://cimg8.ibsrv.net/gimg/bikefor...605834fd4d.jpg
https://cimg0.ibsrv.net/gimg/bikefor...d5dcf4d745.jpg

I've had three different configurations measured and am beginning to see some trends. My measuring technique needs better consistency, Shimano seems to have a narrower range of high and low measurements in general and just because you can read off a scale a thousandth of an inch doesn't mean much in real life drivetrain performance.

The lever's cable pull differences per click for campy averaged nearly twice what the Shimano lever did. And as I expected the cage travel per click was better "controlled" on the Shimano system. No surprises here although I wish the Campy system scored better as I really like the fixed (WRT to shifting) brake lever blade design.

The test rig I did does mimic real bikes largely. I would make a shift to a lower gear at the lever, recycle back down a gear and return to that first shift again then pluck the cable mid point to try to settle all in better before measuring. Friction does seem to make those thousandths of an inch stand out. But the clicks points, and the lever cable travel for each, compared to what the cage was traveling didn't always seem to match up as I thought it would. I blame cable friction here, just like in real life:)

What do I do next? test more combos I have on hand and include the mixed systems that use a ShiftMate. Refine my technique. Think about lowering the cable friction (in these tests the cable was dry and all sliding contacts were in a liner or casing).

I'll continue exploring with the stuff I have on hand and report back with more info as I find it worthwhile. Andy

icemilkcoffee 08-05-22 09:19 PM

Very interesting test setup. What are the actual numbers so far?
is it possible to rig up another dial indicator for the cable travel block? Iím not a big fan of handheld calipers because the repeatability is not great.

jccaclimber 08-05-22 10:42 PM

I'll have to find the data, but I did a similar thing with Shimano 10sp front shifter. Mostly putting this here as a reminder, it's about time to go back to trying to convert my front shifter from a triple to a quad for the tandem.

70sSanO 08-05-22 11:04 PM

I’ve always had the impression that cable pull and RD actuation movement, especially of older systems was not consistent from shift to shift/cog to cog.

As far as your older 90’s Campy setup, I thought the RD actuation ratio was 1.4:1.

I believe the new Shimano Tiagra, 105, GRX actuation ratio is 1.4:1.

It might be possible to run 9 speed Ergos to a Tiagra/GRX RD instead of a Campy RD.

John

nick_a 08-05-22 11:58 PM

Thanks very much for the research, Andy. You're delivering a whole lot of interested future internet people some solid information here. I'm looking forward to your results.

sweeks 08-06-22 05:55 AM

Going from the sublime (Andy's work) to the ridiculous, here's my set-up for measuring the cable travel on my Ultegra front triple shifter to see if I could substitute an XTR shifter.
Answer: No.

https://cimg6.ibsrv.net/gimg/bikefor...0f54217f47.jpg
Paint stir stick, ruler and tape. First prize for "Most Primitive" measuring set-up.

As it turned out, I went to a thumb shifter for the front derailer, and it works well. The XTR shifter, thankfully, was a drop-in replacement for the 9-speed STI.
https://cimg0.ibsrv.net/gimg/bikefor...5347bd8cc2.jpg
Cheap but functional thumb shifter on the left, XTR trigger shifter on the right.

fishboat 08-06-22 08:05 AM

In a past life, if I had your setup to measure what you're measuring, I'd have done a Gage R&R Study. No doubt Shimano and Campy use GR&R or GR&R-type studies to monitor their measurement systems that guide the manufacturing processes used to make the derailleurs/shifters your measuring.

GR&R is a very organized, objective way to determine whether your measurement system is capable of reliably measuring, in this case, derailleur movement or cable pull. It can also be used to identify what, i.e. cable pull, your measurement system can reliably measure. For example, using arbitrary numbers, if a measurement system is determined to be incapable of reliably measuring 3mm of movement, you can use the results of the study to determine the measurement system is capable of reliably measuring 10mm of movement. Another example..if someone needs an accurate determination of, say +/- 0.01mm on a 15mm(target) steel rod diameter, a metric tape measure would be an incapable measurement system while a micrometer would be a capable measurement system.

All that said, a good GR&R study can be a fair amount of work. In a precision production environment, it's a great investment. It would certainly apply to your study, if you want to dive in.

Off the top of my head a couple thoughts.
1. I'd use new cables, if you're not already, just to eliminate any measurement variation noise added by worn, or less than ideal, cables.
2. New shifters would (probably) lower the measurement noise, but wouldn't be practical for what you're doing. I would use the same shifters for all measurements within a study and make sure they are in good condition and lubricated as needed.
3. You seem to be measuring cable pull through the rear derailleur body. I'd think the der body would add random noise to your measurements and degrade your results. It may be useful to measure rear cable pull by measuring the cable movement itself. You could also measure the same cable-pull der movement as you have setup now. In an ideal world they'd be the same, or the same within some consistent scalar amount. A comparison of the two sets of data would tell you how much noise measuring through the der adds. A new versus used der movement would be another study to give you an idea how much influence the der is having on your results.
4. Make sure you use averages for each measurement and not single points. Each data point for each shift-movement should be at least an average of 3 measurements. A better estimate of the true movement would be 10 measurements of each shift-movement. The estimate of the true shift-movement by averaging say 5 measurements isn't (statistically) any better than averaging three points. You need 10 determinations to get a better estimate than averaging 3.
5. It would be time well spent to just take a bunch of measurements (I'd do 10 each for the time being) of shift-movements and determine the average and standard deviation. Then divide the standard deviation by the average and see where you're at. Again, random numbers, if you have an average of 10mm with a std dev of 3.2mm then you have a relative std dev of 32%. Ouch.. If you compare the ave, std dev, and relative std dev of two adjacent shifts you may get some indication of how capable your measurement system is in measuring shift movements. There's more statistics that can be applied to this, but start small first.
6. It's worth the time to sit down and write out exactly the goal of your study(s) and what measurements you'll do to gather your data. It'll help keep you on track and it'll be easier to identify when you stray from goal or process.

Even "simple" studies can get quite complicated.

I think you're on the (critical) right track at the moment as you're asking "what am I trying to do?". If your not sure where you're going then any path will get you there.

79pmooney 08-06-22 08:57 AM

Thanks Andy. I'm still 9-speed and still friction. Went Campy because I will never ride those brake lever operated shifters. For this guy who firmly rests his fingers on the lever side to steady the bars as I remove the other hand to reach down for a water bottle or back for something in my pocket, Shimano levers - at least one crash before I re-train 30 years of habit.

So far, still on my Campy probably Chorus and Veloce wheels and the three+ cassettes worth of cogs look to go a lot longer. (And I love thjat that era Campy had one assembly of three cogs, 19-21-23 and all the rest were individual. Makes customizing cassettes easy. Love having three top cogs, 12m, 13 and 14, and being able to skip the next. I run 12, 14-whatever most of the time to have the big one to steady the bike coming down the Portland hills and one more useful middle cog.

But someday I'll probably have to grow up and get with it. And it doesn't look likely that Shimano will make a brifter for me so I might end up in a cable pull no-man's land and needing an Andy Stewart travel agent.

jccaclimber 08-06-22 11:57 AM


Originally Posted by fishboat (Post 22600513)
In a past life, if I had your setup to measure what you're measuring, I'd have done a Gage R&R Study. <massive snip>

While youíre at it you might as well reject the results for not using instrumentation with a current NIST traceable calibration and operating in a temperature and humidity controlled environment.

fishboat 08-06-22 12:13 PM


Originally Posted by jccaclimber (Post 22600716)
While youíre at it you might as well reject the results for not using instrumentation with a current NIST traceable calibration and operating in a temperature and humidity controlled environment.

Sarcasm..not really needed. Given what's being studied and the instruments being used.. NIST, temp, and humidity is going a bit far. If you think skipping the evaluation of measurement system error is a waste of time, then you've never really done work where it matters. If measurement error is significant in a study(relative to what's being studied) then the entire study will be a waste of time. I doubt anyone wants to make a few hundred measurements only to end up with a shrug of one's shoulders and an "I don't know..?"

What are your thoughts on how Andy should proceed?

jccaclimber 08-06-22 01:29 PM

Just yesterday I approved a PPAP for a high volume part with a Cpk > 5 on a 0.008 mm wide tolerance band. Admittedly that's the highest Cpk I've actually seen in the wild, but if you understand the significance of that you'll also understand that it requires excellent process control, and a very consistent measurement system, to achieve.
1. While I did throw some snark in there, basic calibration should always be done if you're to the point of an R&R.
2. Throwing in some more snark, a gage R is probably more relevant than an R&R unless you expect the OP to conscript 2 friends for this study.
3. My main point was more about appropriate levels of effort for the task at hand. The OP has already concluded that his measurement technique needs improvement. An inspection of the measurement system is a lot of work to confirm what has already been concluded. A lot of time some common sense will tell you if your measurement system is sufficient without the rigor of a full study. Other than the gage R&R part, the rest of the post seems to be good relevant advice.
4. Assuming that a lower force indicator is not available, stiffening the system up and measuring closer to the attachment points would help. At first glance the setup through the rear dropout looks stiffer than the plate attached to the derailer. I'd set the indicator up to measure directly off of the inner cage plate at the pivot.
5. Sprocket spacing is probably a published value, and can be easily determined by measuring a cassette off the bike. Ideal lateral derailer movement should match this value, so we know the target as well.

Knowing cable pull and knowing derailer movement aren't quite the same. I'd expect the derailer to have equal movement per shift from one end of the range to the other. I would expect cable movement per shift to vary slightly to account for the change derailer geometry through the range.

I'd measure cable pull as close as possible to the shifter. Taking it right at the downtube is a good start. When I did it I clamped the handlebars to a bench (granite surface plate in my case), put a pulley and weight on the cable end, and measured travel right near the cable. This removes the housing, and associated error, from the system.

Andrew R Stewart 08-06-22 02:03 PM

icemilkcoffee- I agree about hand help calipers not being very repeatable in measured numbers.

When I started to figure out how I would do this I did consider using a dial on the cable pull measurement, the 2" dial was bought for this and I fitted a flat back to allow a closer positioning to the down tube, so the indicator point might hit the cable block tight to the cable. One issue with the cable block is that the cable will sag down just under the weight of the block. To add an off center pressure (the indicator point) would increase this and result in more deflection to the cable measurement. I had hoped that a longer cable block would reduce the sag (and as I write this I realize that rotating bike so the cable is vertical would eliminate this. Oh, how the creative process works...)

I mentioned technique. In the 5 tests I've done I saw some changes of values dependent on how I cycled through the shifting range. Quickly I decided to "standardize" my technique to have any real ability to compare or extrapolate from. The two initial test runs I discarded as being relevant to the system design and about learning how to work the set up. This will evolve. Andy

jccaclimber 08-06-22 02:08 PM

One more note, it looks like my first pass at determining cable pull per shift was repeatable within +/- 0.05 mm (0.002") across 5 runs. The instrument I was using has sub micron repeatability, so the variation was all my setup and the front shifter. The upshift data was noisier than the downshift data.

Something I have not seen in this thread is an idea of how close is close enough. +/- 0.1" is likely too coarse, and the 2 nm flatness of our interferometer calibration artifact is likely not needed.

The rear derailer adjustment screws I've measured have all been M5x0.8, and the smallest adjustment range is 1/8 turn, which equates to 0.1 mm as the smallest adjustment. A single detent of adjustment doesn't make much difference, so I'll argue anything under half of that is good enough for what we're doing. Parenthood has thrown that particular project on the back burner, so I probably won't have more data any time soon.

jccaclimber 08-06-22 02:17 PM

Yet another ďone more noteĒ. I also found more variability in position than I wanted as I was setting up my experiment, and concluded making sure everything in the shifter was seated would help.

In your case, after you orient the bike so that cable section is vertical, you might also secure some weight to the cable somewhere downstream. This will help over-ride friction in the system.

Andrew R Stewart 08-06-22 06:28 PM


Originally Posted by fishboat (Post 22600513)
in a past life, if i had your setup to measure what you're measuring, i'd have done a gage r&r study. No doubt shimano and campy use gr&r or gr&r-type studies to monitor their measurement systems that guide the manufacturing processes used to make the derailleurs/shifters your measuring.

Gr&r is a very organized, objective way to determine whether your measurement system is capable of reliably measuring, in this case, derailleur movement or cable pull. It can also be used to identify what, i.e. Cable pull, your measurement system can reliably measure. For example, using arbitrary numbers, if a measurement system is determined to be incapable of reliably measuring 3mm of movement, you can use the results of the study to determine the measurement system is capable of reliably measuring 10mm of movement. Another example..if someone needs an accurate determination of, say +/- 0.01mm on a 15mm(target) steel rod diameter, a metric tape measure would be an incapable measurement system while a micrometer would be a capable measurement system.

All that said, a good gr&r study can be a fair amount of work. In a precision production environment, it's a great investment. It would certainly apply to your study, if you want to dive in.

Off the top of my head a couple thoughts.
1. I'd use new cables, if you're not already, just to eliminate any measurement variation noise added by worn, or less than ideal, cables. only one cable and it and the casing are new and dry of lube (as i will be changing out levers and ders lube would get messy)
2. New shifters would (probably) lower the measurement noise, but wouldn't be practical for what you're doing. I would use the same shifters for all measurements within a study and make sure they are in good condition and lubricated as needed. both shifters (and ders) are used but do function well and don't show wear or slop beyond what i feel is normal
3. You seem to be measuring cable pull through the rear derailleur body. no, the cable pull is measured at the cable's exiting the down tube casing stop. For this no der would even be needed as long as some sort of tension could be applied to the cable i'd think the der body would add random noise to your measurements and degrade your results. It may be useful to measure rear cable pull by measuring the cable movement itself. You could also measure the same cable-pull der movement as you have setup now. In an ideal world they'd be the same, or the same within some consistent scalar amount. A comparison of the two sets of data would tell you how much noise measuring through the der adds. A new versus used der movement would be another study to give you an idea how much influence the der is having on your results.
4. Make sure you use averages for each measurement and not single points. i was averaging the measurements and for this series was doing them twice but i think 3x would yield better results. each data point for each shift-movement should be at least an average of 3 measurements. A better estimate of the true movement would be 10 measurements of each shift-movement. The estimate of the true shift-movement by averaging say 5 measurements isn't (statistically) any better than averaging three points. You need 10 determinations to get a better estimate than averaging 3.
5. It would be time well spent to just take a bunch of measurements (i'd do 10 each for the time being) of shift-movements and determine the average and standard deviation. Then divide the standard deviation by the average and see where you're at. Again, random numbers, if you have an average of 10mm with a std dev of 3.2mm then you have a relative std dev of 32%. Ouch.. If you compare the ave, std dev, and relative std dev of two adjacent shifts you may get some indication of how capable your measurement system is in measuring shift movements. There's more statistics that can be applied to this, but start small first. this is some of what i am considering next. I have a good friend who taught college stats and has worked for various industries (he would have to kill me if he told me the companies
6. It's worth the time to sit down and write out exactly the goal of your study(s) and what measurements you'll do to gather your data. It'll help keep you on track and it'll be easier to identify when you stray from goal or process. i know what my final goal is and if i never reach it this is fun anyway. Andy

even "simple" studies can get quite complicated.

I think you're on the (critical) right track at the moment as you're asking "what am i trying to do?". If your not sure where you're going then any path will get you there.

88

Andrew R Stewart 08-06-22 07:16 PM

I had no idea this project of mine would generate this much response. Thanks for the feedback so far, I am learning.

Someone suggested placing the indicator's tip against the inner cage plate. This was my first thought too, but I found that the slanted parallelogram resulted in the cage changing its position WRT the tip. Hense the plate bolted to the outer plate by the guide pulley hole. A curious finding is that the Shimano der has about 25% more of this plate/tip relative movement. Due to the longer parallelogram links (I think).

Here's the raw data recordings. Sorry for the photo quality but I just found that my printer won't scan to my computer. The measurements are in black and the red is the difference between each index click. The bottom of each slip has the average cable pull, the average cage travel per click and the calculated actuation ratio. (I will create a larger data recording form that will have 3 measurement recordings, their average, the click to click difference, the average differences and that actuation ratio). These slips show my lack of focus and getting lost in the order a few times, Hence the need for better organization of the recording format. Andy
https://cimg6.ibsrv.net/gimg/bikefor...d60562ce22.jpg

jccaclimber 08-06-22 10:22 PM

If you screw a flat plate in the place of the inner cage you should get a decent surface. Don't feel bad making it thicker than the original plate, that just means you'll need longer screws.

Andrew R Stewart 08-07-22 08:00 AM


Originally Posted by jccaclimber (Post 22601234)
If you screw a flat plate in the place of the inner cage you should get a decent surface. Don't feel bad making it thicker than the original plate, that just means you'll need longer screws.

Have you looked at the photo of the rear set up? You'll see that plate I use is bolted to the cage. Andy

jccaclimber 08-07-22 10:50 AM


Originally Posted by Andrew R Stewart (Post 22601489)
Have you looked at the photo of the rear set up? You'll see that plate I use is bolted to the cage. Andy

Yes, but cantilevered. Same concept but I was trying to imply the plate going through both ends, and the measurement point kept between them.
With many of these, the perpendicular itís of that plate vs. the direction of derailer movement will also influence the measurement. I didnít go through the results you posted to see how much noise is in the data, just noted your comment that it was noisier than you wanted.

Andrew R Stewart 08-09-22 07:14 PM

More mods and better measurement recording- I made a dial indicator clamp and set up for the lever/cable measurements. (While a lathe is a beautiful thing a mill is pretty cool too). The measurements are now far more reliable and "stupid free" (not completely but far nicer than making each shift cable movement with a hand held caliper). A couple of immediate observations. I had concerns about the block that is clamped to the cable causing droop in the cable which might add noise to the measurements. The dial holding clamp's V groove bottom (it's crotch) slightly touches the cable and adds some support/stability to the cable. I reversed the dial's pointer direction so its spring is, like the der dial pointer's spring, helps to overcome cable friction in the upshifting direction.

I recorded the Shimano Tiagra lever and Deore der on the charts I drew up. These charts are still a work in progress but are nicer to use and also help me keep track of the various steps to get a full range recorded. Nore that the numbers vary by very little per shift. Both at the lever/cable end and the der end. I only did two series, time and the very consistent results had me not bother with a third run. I'll get around to doing the rest of the math later but since it's not a Shimano lever I am wanting to work with this follow up isn't too important. I am impressed with how little scatter there is for the two series of measurements. Only a few thousandths of an inch most of the time between the two runs. It remains to be seen how the Campy lever measures up. I am rather happy with this at this point.

Next will be measuring a bunch of lever/der/Shiftmates. What might be called the boring part of a project. Andy

https://cimg2.ibsrv.net/gimg/bikefor...5ec383c65d.jpg
https://cimg3.ibsrv.net/gimg/bikefor...d5d2856fec.jpg

nick_a 08-09-22 09:21 PM

Keep up the good work Andy, a lot of this work posted to BF is why I ever even considered doing my own bike work. Thanks again.

jccaclimber 08-14-22 09:09 PM

Andy,
All valid experiments should be repeatable, so I went ahead and threw something together to try to validate your numbers. It wasn't nearly as robust a setup as my previous measurements (fastened to a granite surface plate, no housing sections to compress, a weight on the other end of the cable, etc. I don't have any 9sp shifters other than the ones on my bikes, but the results still seem reasonable.

The setup:
https://cimg4.ibsrv.net/gimg/bikefor...368f84743a.jpg
https://cimg5.ibsrv.net/gimg/bikefor...a921df0872.jpg

Some observations:
1. I should have flipped the indicator around the other way, as you did.
2. Putting the jog on the indicator tip rather than the item attached to the cable prevents the cable from being being displaced as much by the force of the indicator. I haven't done the math to see how much this influences the results, but my guess is not much.
3. The 1-2-3 block secured to the water bottle mount on this frame is NOT a particularly rigid method of attachment, mostly because the bosses are not flat on this frame. It does however work for a quick setup, and I'm not planning to re-use it as you are.
4. I could introduce a full mm of movement by greatly increasing cable tension by hand. All of it appears to be in the housing run from the shifter to the downtube stops. I was a bit surprised simply because I have no shifting issues whatsoever on this bike.

Results next post.

jccaclimber 08-14-22 09:23 PM

Ok, now the interesting part.
1. My upshift (cable release) results were much more consistent than my downshift (cable pull at the shifter) results, so I used those.
2. This is done on a 1st gen (silver caps, 2000ish?) 9sp Ultegra STI shifter in sub-par condition.
3. This plot is cable pull between sprockets, so there are only 8 entries for the 9 speeds.
4. My 2 results are in red. Your 2 results are in blue (from your data in post #20).
5. I defined #1 as the large sprocket in the back and #9 as the small one (11 tooth in my case). I think we numbered our data in opposite directions. If this is not the case, then something is off, so please point it out if so.
6. In general our results are very similar. The end values are very different. This makes sense as those positions are controlled by the derailer limit screws, not by the shifters themselves.
7. As suspected, the cable pull per shift is not constant. We know (or at least I strongly suspect) that the sprocket to sprocket spacing is constant, so as a result you can expect derailer ratio to change through its full travel.
https://cimg3.ibsrv.net/gimg/bikefor...fb5a95a5d6.png

Troul 08-14-22 09:38 PM

if it helps, you could use plastic blocks that are affixed to the cables to lighten the load.

CliffordK 08-15-22 04:01 AM

I use this page for a reference page.

https://en.wikibooks.org/wiki/Bicycl...ing_Dimensions

However, as you are seeing, shifts aren't entirely consistent across the range.

Keep in mind that Campagnolo changed their shift ratio mid production of the 9 speed.

I had thought of using a laser pointer to measure movements, but you undoubtedly get much higher accuracy with the dial indicator, as long as it doesn't impact shifting.


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