when did shimano change their RD pull ratio?

[vqdriver]

if i have a 7sp shimano rear der and put a 8 or 9 sp shifter and cassette on there will it work??

[seanile]

i don't think the rear derailleur matters, it's just a spring-loaded parallelogram. the pull ratio is determined by the shifter. but i'm not completely sure and am happy to be educated.

[PacNW2Ford]

if i have a 7sp shimano rear der and put a 8 or 9 sp shifter and cassette on there will it work??

Yes, as long as the RD isn't early (7400) Dura-Ace. Even then, there is a workaround. I believe it didn't change until after 10-speed. I am running a 7800 10-speed RD on 9-speed.

[Veloo]

Yeah, I learned the "hard" way with the clutch RD.

https://forums.thepaceline.net/showthread.php?t=248416&highlight=4700

[dddd]

Shimano 7s rear derailers will move far enough to span an 8s or 9s cassette, but usually suffer a loss of indexing accuracy when engaging the largest cog as the actuation ratio goes out of linearity.

So the result may be that a necessarily-tighter cable adjustment then results in sluggish shifting toward the smaller end of the cassette.

Shimano's Dura-Ace derailers (both front and rear!) were finally given the same actuation ratio as the rest of their line in 1997 (when 7700 9s arrived).

Their 10s MTB gruppos got a newer-yet actuation ratio, and their 11s road gruppos got yet another unique actuation ratio.

The Pre-1997 Dura-Ace was the original SIS ratio that their other gruppos never copied. It had the shortest cable movement so was less tolerant of longer cable runs, and was more sensitive to dirty cable housings.

[vqdriver]

Thanks all

[bikinchris]

if i have a 7sp shimano rear der and put a 8 or 9 sp shifter and cassette on there will it work??

You mean since yesterday? Shimano's pull ratios are a patchwork. Sometimes the same named components will have different pull ratios in the same year. Of course MTB and road are different too.

[dave thompson]

The Road rear der ratio changed fundamentally with the advent of 11-speeds:5800/6800 and later. In MTB ders it started with 10-speed.

[dvs cycles]

I think 7 and 8 were the same as they just made the free-hub wider.
9, 10 and 11 are all different from each other.

[rccardr]

Sigh.
Enough with the urban legends already.

Shimano 6-7-8-9-10 speed Road components are all forward-backward compatible with the exception of Dura Ace 740X.
Note that I said ‘Road’.
MTB components are compatible with Road components except the aforementioned DA 740X, at least the shifty bits, in all 6-7-8-9 speed ranges.

So, yeah, you can put a Deore 8 speed RD on your STI shifted 9 or 10 speed bike and get up to a 34 rear cog. Nice. Or you can replace that hatcheted 7700 RD with the old 6708 RD in the parts bin to shift your 12-28 ten speed cassette just fine.

Everything changes with 11 speed road and 10 speed MTB (and some kinda Tiagra stuff) but otherwise it all plays together nicely.

[dddd]

Sigh.
Enough with the urban legends already...

Such as the urban legend that an early 6s Ultegra or 105 rear derailer will index perfectly with an 8s shifter?
I have read such bicycle-related legends myself, on popular sites.
The real world is a different place though, and I've had people bring in bikes that were "supposed" to work correctly with legendary older derailer replacements from the 80's, but didn't.

For this reason, when Shimano's 8s derailers became available in their various groups, the cages were marked something like "Integrated-8" or some such. But it would be some years later before it finally became obvious to me why they were marked that way (it wasn't just marketing).

9s cassettes weren't significantly wider than 8s, so all of the Shimano 8s derailers were fine with those if the cassette wasn't too large, but 10s road was a different story and lots of such bikes were quite sensitive to so much as a worn pulley or an alternative-brand chain.

Things we learned the hard way!

[ColonelJLloyd]

Such as the urban legend that an early 6s Ultegra or 105 rear derailer will index perfectly with an 8s shifter?
I have read such bicycle-related legends myself, on popular sites.
The real world is a different place though, and I've had people bring in bikes that were "supposed" to work correctly with legendary older derailer replacements from the 80's, but didn't.

Definitely an urban legend as there was no 6s Ultegra. ;)

[dddd]

Definitely an urban legend as there was no 6s Ultegra. ;)

Ah yes, I wasn't even messing with any of this SIS stuff until the 90's.
Quoting my own post, above, "For this reason, when Shimano's 8s derailers became available in their various groups, the cages were marked something like "Integrated-8" or some such. But it would be some years later before it finally became obvious to me why they were marked that way (it wasn't just marketing).
Yeah, the 6s ones were labeled 600, actually the very first such derailer that I had indexing problems with on a bike (Maruishi Record) that I had upgraded with 8s wheelset and STI levers.
I wasn't too bummed though, since I bought the Maruishi at an upscale apartment complex garage sale in Silicon Valley for all of $20 in new condition! I later donated it to Trips-for-kids because it was more than a tad too small, was a pinkish salmon color and I didn't have a girlfriend who wanted to ride it.

[Fivethumbs]

I never really understood the Shimano numbering system. Shimano 600 Ultegra STI shifters are 6400 but work better with a 6401 derailleur. Shimano 105 STI shifters are 1055 but work better with a 1056 derailleur. I've run 6400 and 1055 derailleurs on 8 speed STI and they've been less smooth and noisier. On another note, the front derailleur pull ratio changed when 8 speed STI was introduced so don't try to use a 6400 or 1055 front derailleur with 8 speed STI. The 6401 has two different cable mounting positions - one for down tube shifters and one for STI.

[oldpotatoe]

if i have a 7sp shimano rear der and put a 8 or 9 sp shifter and cassette on there will it work??

In a nutshell..7402 8s DA, shimano 10s MTB, and shimano 11s...different pull ratios and non compatibility with other than those, shifters. If that rear der isn't toasted, it should work fine.

[rccardr]

Such as the urban legend that an early 6s Ultegra or 105 rear derailer will index perfectly with an 8s shifter?
I have read such bicycle-related legends myself, on popular sites.
The real world is a different place though, and I've had people bring in bikes that were "supposed" to work correctly with legendary older derailer replacements from the 80's, but didn't.

I don’t want to get into a disagreement over combinations that are unlikely to be used these days by most folks, but in my experience (which is fairly extensive) with these components they do, indeed, index perfectly. Again, setting aside the 740X, 10 speed MTB, etc. stuff mentioned in my former post.

For an extreme example, I’ve shifted a Shimano 600 RD (6208 series, the first non-DA indexed Shimano RD) across a 10 speed Shimano cassette using a Shimano 7900 series shifter. Worked perfectly. Have also had good experience shifting a 6 speed Deore RD across an 8 speed Shimano cassette using 8 speed Shimano 600/Ultegra shifters.

Understand completely that ‘customer’ bikes are not always in the kind of condition that results in ideal shifting, and that in all cases the use of premium cables & housing and the condition of all the components in the shifting sequence have a bearing on shift quality.

[dddd]

One thing that comes to mind, whether it has to do with opinions about bottom bracket taper compatibility or derailer/shifter compatibility, is that it never hurts to test-fit the parts to see how they perform and whether the result meets one's standards.
And, that subtleties like dropout hanger length, cable guide configuation/radius and/or the particular brand of chain can all have significant effect on perceived results.

It's not a big deal then if someone wants to try what I and others have tried, and which perhaps didn't meet standards. It's just that I like to get it out there what the problem could be, based on what I dealt with, so that time/effort might be spared. I know that in my case, I heard others saying for instance that "the hanger must be bent" (when I had already checked that).

[rccardr]

Yep, all good points.

[rayms]

Yes, as long as the RD isn't early (7400) Dura-Ace. Even then, there is a workaround. I believe it didn't change until after 10-speed. I am running a 7800 10-speed RD on 9-speed.
What is the workaround?
Also could someone tell me if the Dura Ace word on the derailleur is raised above the black background?

[oldpotatoe]

What is the workaround?
Also could someone tell me if the Dura Ace word on the derailleur is raised above the black background?

Mount the cable above the fixing bolt rather than below it.

Also one bolt head seen, not two. The '2 bolt' is compatible with 8s, 9s, the 'one' bolt is unique to DA.

[jamesdak]

Sigh.
Enough with the urban legends already.

Shimano 6-7-8-9-10 speed Road components are all forward-backward compatible with the exception of Dura Ace 740X.
Note that I said ‘Road’.
MTB components are compatible with Road components except the aforementioned DA 740X, at least the shifty bits, in all 6-7-8-9 speed ranges.



I was reading through these posts just chuckling at some of the responses until this one. I've been through at least 80 some old steel bikes over the past decades and have upgraded many. The old Shimano RD's were one of the least troublesome issues as I took many a bike from 6-7 speed to 8, 9, or 10. Very few exceptions to them not working and I honestly can't remember a time running into the problem.

[unterhausen]

I was marveling at how Shimano has totally abandoned any desire for any sort of cross compatibility since the 10 speed road/9 speed mtb days. It just can't be that important to change pull ratios. At some point there are diminishing returns from those changes.