Effect of cable pull on RD shift quality - Dynasys 10sp
 

I'm considering upgrading one of my bikes to 10 speed Gevenalle control levers. That means I would have the opportunity to choose between traditional Shimano 10 speed road compatibility, or 10 speed Dyna-Sys, which is supposed to pull much more cable per shift, at the expense of needing a new RD. Losing the ability to use a road RD is a non-issue, as I've been running mountain 9-speed RDs on all my bikes for years to get the increased chain wrap.

I know that a longer cable pull helps when things get really muddy and messy, but what about ordinary road riding in fairly mild conditions (i.e. the occasional rainy ride and some grit during the winter)? I've always found Shimano 10 to be a bit fussy, at least when paired with a mountain RD. If Dyna-Sys 10 can shift as reliably as, say, my touring bike with 9 speed barcons, it would be worth the expense of upgrading the RD.

Old (pre 4700 Tiagra) 10 speed cable pull is problematic IMO.
I'd go with a more cable pull option.

It's already a 10? That's why you're not going straight to 11?

It's mostly because I don't have any 11-speed compatible wheels right now. Aside from the expense, as a clyde I'm concerned that the 11 speed hubs seem to be squeezing the drive side flange inboard to make room for the cassette, which increases spoke tension imbalance and reduces lateral stiffness. It just doesn't seem like much of an upgrade.

Many 11-speed mountain cassettes fit on 10-speed hubs. The largest dinner plate cog over-hangs the hub flange. Since you're already considering running a mountain rear derailluer, you probably won't mind the range anyway.

Thanks for the info. I haven't been paying much attention to the 11 speed mountain market, and didn't realize that you can get away with 10 speed hubs in some cases. I'll have to do more research into that option.

Either way it's a similar question: how does it shift compared to 10 speed road. If 11 speed Dyna Sys is about as finicky as 10 speed road has been (in my experience), then it's not worth the even larger upgrade expense.

I still want someone with the hardware to test my theory that a Shimano 11 speed road shifter should shift a 9 speed SIS system just fine.

In my experience so far 10 spd Shimano mountain is very hit or miss. Some stuff seems great and is very tolerant of maladjustment and other combinations are absolutely terrible. In particular I found early SLX 10spd great, now not so much.

Also seems like it's very sensitive to chainline and chainstay length. My experiment with a 10spd 1x drivetrain resulted in some odd behavior when I got the chainline in far enough to shift a 36t cog. The chain would wobble back and forth on the second smallest(probably a 13t?). Super weird, never seen it before.

Not the same cable pull per gear change.

7) Bicycle rear shifter compatibility - Cycle Gremlin

Here's a thing I wrote about why I suspect the Shimano and Campy 11 are closer than websites like your link report: http://www.bikeforums.net/19060234-post11.html I just wish I had the parts and time to try it!

First, I take the tables as source material, because I know there was no grand original project, it's just an accumulation... so there are some accumulated errors from people copying and pasting them for years, without supporting data and rounding off the third digit. You still sometimes see different ratios listed for Shimano 10 and 11 mountain derailleurs which was based on an erroneous early report that Shimano 11 MTB would have the same cog spacing as 10, which I think sprang from the fact it still went on 8-9-10 freehubs; instead it turned out to be the same as all the other 11's, and the derailleur parallelogram is identical. It's pretty rare that you see original source measurements of cable pull, except hearing from someone that it worked or didn't.

Second, there's also the problem that a shift-per-click isn't always perfect for a Shimergo setup because it doesn't use the last two stops, throwing off the average. But the average is sometimes all you get because the first person who got it to work just measured the distance between the stop and the pinch bolt in first and 11th. I have a Shimergo 9-11 setup and it works even though the table says it's off, because the lower shifts are bigger.

And finally, the spacing only needs to work pretty close for 3 or 4 clicks on either side of whatever you set as perfect. The top position is big and sloppy so the RD position can be set by the limit screw. Some slop is allowed by the Centeron pulley, and that gives you some leeway to set it perfectly in 4th-5th and still be close enough at 1st and 8th. So, if it doesn't work the 9 SIS, it would probably work the 8 and that would still be good to know. And what do the 4700 shifters do?

Shimano and Campagnolo 11 speed are very close.

Getting 8 out of 10: even for mix matching 7 and 8 speed shifters and cassettes, the difference in cable pull is enough to make it work so-so, especially in some gears. I was unpleasantly surprised when trying it, having considered a small number of shifts and very small differences in both cable pull and sprocket pitch.

As for data confirmation, shifter cable pull times RD movement ratio equals cassette cog pitch. If one of the data is incorrect, by more than 0.1 mm, one (or more of) the data is incorrect. Some don't add up, like you've noted.
11 speed Shimano road shifters allegedly have a pull of 2.7 mm per click. With which RD and cassette, apart from 11 speed Shimano road ones, would you say it also works?



Tiagra 4700 RDs have the same movement to cable pull ratio as Shimano road 11 speed RDs. They pull more cable per shift than older Shimano 10 speed shifters. 4700 RDs can work with Shimano 11 speed road shifters and 4700 shifters work with Shimano 11 speed road RDs.

EDIT:
I've cross checked all the data from my site at least. It adds up, within 0.1 mm of (rounding) error.
Shimano 11 speed road shifters pull 2.7 mm per click.
Shimano 11 speed road RD moves 1.4 mm per 1 mm of cable moved.
This results in 3.78 mm of RD movement per click.
Cog pitch of Shimano road 11 speed cassettes is 3.74 mm.

So the error in data is within the rounding to 1 decimal precision.

Double checked for all the other data and it seems correct.

Nope. It would work as an 8-speed cassette, but why you'd do that is beyond me.

Here's a much bigger chart with all the numbers.
Art's Cyclery Blog » Science Behind the Magic | Drivetrain Compatibility
We can take the pull distance and the cog pitch as givens, because they are relatively easy to measure.

A 9 speed SIS derailluer has a cable pull of 2.5mm and a pitch of 4.35mm, so the derail ratio is 1.74.
An 11-speed road shifter has a pull of 2.7mm. Used with a 9-speed SIS, gives a cog pitch of 4.7mm, that's definitely way too large.

Interestingly, an 11-speed SRAM road shifter paired with a Shimano Dyna-sys RD or 10-speed SRAM RD, would probably work with an 11-speed mountain cassette. Just an interesting option for the low gear crowd.

It should work. :)
Also, SRAM 1:1 standard, with RD movement ratio of 1.1 mm is the same as Shimano 11 speed road RD movment ratio. Anyone tested compatibility (11 speed Shimano road cassette and shifters, with 1:1 RD)? :)

If, for instance, your 9-speed DA shifters pack it in and you want to replace them with something nicer than Sora, without replacing your whole drivetrain.

Or, no manufacturer sells a really wide range groupset with brifters. It's all hacks, and the hacks have been getting more difficult since the end of SIS. The 4700 shifters are the best STI's still available as a triple and so if you can get it to run an SIS system - be it 8 or 9 - it will allow you to make a really wide-range drivetrain with an SGS RD and run it with brifters.

And, just because figuring this stuff out and tinkering with it is fun.

Were I you I'd go the 10sp Dynasys option--my experience is that it is far more robust and fault tolerant. Additionally, if you want a mountain sized cassette (40t big cog) I'd go 11sp, as 11sp Shimano mountain basically dishes the big cog inboard to fit on a 10sp freehub.