# Might have made a mistake buying shadow plus



## Hiebs915 (Sep 14, 2012)

Hey guys,

I just bought a Shadow plus xt derailleur. 

The model is: Shimano XT Shadow Plus Rear Derailleur RD-M786-GS

I was planning on doing 9 speed cassette because I have a Shimano slx 665 front crank. I have already purchased 9 XT shifter too. 

Will the derailleur I bought work with my setup? I was under the impression I could use it on a 9-speed cassette. I got it on ebay so returning it isn't really an option.


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## Larry_K (Jul 10, 2010)

A 10sp rear derailleur will not be compatible with a 9sp drivetrain, so that will not drop into your current setup.


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## DudeNudem (Jun 11, 2012)

I just looked it up: Shimano M640 Zee Rear Derailleur > Components > Drivetrain > Rear Derailleurs | Jenson USA Online Bike Shop

Is that what you have? The ten speed stuff is not backwards compatable from what I understand so it wont work with a nine speed chain and cassette (the 10 speed chain is much skinnier than the 8 and 9 speed so all the 10 speed stuff is built for a narrower chain.)

Sorry man - maybe you can sell it?


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## Hiebs915 (Sep 14, 2012)

DudeNudem said:


> I just looked it up: Shimano M640 Zee Rear Derailleur > Components > Drivetrain > Rear Derailleurs | Jenson USA Online Bike Shop
> 
> Is that what you have? The ten speed stuff is not backwards compatable from what I understand so it wont work with a nine speed chain and cassette (the 10 speed chain is much skinnier than the 8 and 9 speed so all the 10 speed stuff is built for a narrower chain.)
> 
> Sorry man - maybe you can sell it?


No, that isn't what I have.


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## Hiebs915 (Sep 14, 2012)

Damn... Well, I haven't bought a cassette yet. I could buy a 10 speed cassette and a 10 speed shifter, sell the 9 speed shifter. 

Will the SLX crank work using a 10 speed cassette? If not, could I change the chain rings on the crank so it would?


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## Varaxis (Mar 16, 2010)

Pair that 10 spd Shadow Plus RD with a SRAM 9 speed shifter. They have similar cable pull ratio and it's indexed for 9 speeds. People have done this in order to stay 9 speeds, yet get the benefits of the Shadow Plus clutch mechanism. I honestly prefer the feel of SRAM 9 speed shifters over Shimano 9 speed shifters.

The GS model is their short/medium cage model, so hope you aren't planning on running a wide range of gears with that.


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## Hiebs915 (Sep 14, 2012)

Varaxis said:


> Pair that 10 spd Shadow Plus RD with a SRAM 9 speed shifter. They have similar cable pull ratio and it's indexed for 9 speeds. You get 9 speeds + benefits of Shadow Plus.


Hmm. I'll look into it. I'd like to stick to the same brand throughout though.

I'll probably end up selling the 9 speed shifter, getting a 10 speed instead, and just go 10 speed with the cassette. Looks like most people have used the slx crank with 10 speeds already.


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## TwoTone (Jul 5, 2011)

Hiebs915 said:


> Damn... Well, I haven't bought a cassette yet. I could buy a 10 speed cassette and a 10 speed shifter, sell the 9 speed shifter.
> 
> Will the SLX crank work using a 10 speed cassette? If not, could I change the chain rings on the crank so it would?


Yes the front rings will be fine. Is you crank a double or triple? You have a medium cage which is normally for doubles, not triples. Just making sure you know that.


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## Varaxis (Mar 16, 2010)

Sounds like you're wanting to spend extra money... it's wiser, financially, to just go with the SRAM shifter. Better lever feel and you don't even see much of it anyways. 9 speed drivetrain parts are also much more affordable compared to 10spd. Don't forget that you need a 10 speed chain for that 10 spd drivetrain too.


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## Berkley (May 21, 2007)

Varaxis said:


> Pair that 10 spd Shadow Plus RD with a SRAM 9 speed shifter. They have similar cable pull ratio and it's indexed for 9 speeds. People have done this in order to stay 9 speeds, yet get the benefits of the Shadow Plus clutch mechanism. I honestly prefer the feel of SRAM 9 speed shifters over Shimano 9 speed shifters.
> 
> The GS model is their short/medium cage model, so hope you aren't planning on running a wide range of gears with that.


Huh? SRAM and Shimano are not compatible. This _might_ sort of work, but it definitely won't work well. Mixing non-compatible brands as well as drivetrains of different speeds is a bad idea.

The OP either needs to buy a 9 speed Shimano derailleur to fit his shifter, or convert to a 10 speed Shimano drivetrain.


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## TwoTone (Jul 5, 2011)

Berkley said:


> Huh? SRAM and Shimano are not compatible. This _might_ sort of work, but it definitely won't work well. Mixing non-compatible brands as well as drivetrains *of different speeds is a bad idea. *
> 
> The OP either needs to buy a 9 speed Shimano derailleur to fit his shifter, or convert to a 10 speed Shimano drivetrain.


Not true, it has been done by a ton of people without problems as long as it's a 9spd crank and rings with the rest being 10 speed.

From bikerader: Shimano SLX M665 Double Crankset Review - BikeRadar

"Standard SLX M660 cranksets have three chainrings but you can also get this chunky double-plus-bashguard unit with 170 or 175mm arms.* It's intended for use with a nine-speed cassette but we ran a narrow 10-speed chain on it without any problems.* For all intents and purposes it's a much more durable version of the standard SLX crankset. "


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## Hiebs915 (Sep 14, 2012)

Ok guys. I haven't decided on what I'm going to do yet but I found the same derailleur on ebay and it says it *can* work with 9 speed cassettes and shifters. Take a look.

Shimano XT M786 Direct Mount Shadow Plus SGS Long Cage Rear Derailleur Black | eBay


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## Berkley (May 21, 2007)

TwoTone said:


> Not true, it has been done by a ton of people without problems as long as it's a 9spd crank and rings with the rest being 10 speed.
> 
> From bikerader: Shimano SLX M665 Double Crankset Review - BikeRadar
> 
> "Standard SLX M660 cranksets have three chainrings but you can also get this chunky double-plus-bashguard unit with 170 or 175mm arms.* It's intended for use with a nine-speed cassette but we ran a narrow 10-speed chain on it without any problems.* For all intents and purposes it's a much more durable version of the standard SLX crankset. "


You're missing the point. This is the point:



Me said:


> Mixing non-compatible brands *as well as* drivetrains of different speeds is a bad idea.


The cranks will work fine. But that's not the issue. A 9 speed SRAM shifter with 10 speed Shimano derailleur is the problem.


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## shibiwan (Sep 2, 2012)

Varaxis said:


> Pair that 10 spd Shadow Plus RD with a SRAM 9 speed shifter. They have similar cable pull ratio and it's indexed for 9 speeds. People have done this in order to stay 9 speeds, yet get the benefits of the Shadow Plus clutch mechanism. I honestly prefer the feel of SRAM 9 speed shifters over Shimano 9 speed shifters.
> 
> The GS model is their short/medium cage model, so hope you aren't planning on running a wide range of gears with that.


*You can't mix and match between SRAM and Shimano rear derailleurs/shifters.* The SRAM uses a 1:1 pull ratio while the Shimano uses a 2:1 pull ratio.

To the OP - you can try using the 9 speed shimano shifter in your setup. It should work fine since the inter-gear spacing is pretty much determined by the shifter and not the rear derailleur. There is a slim chance that you may have some interference problems with the RD and a 9-speed chain (i.e. noisy) and in this case, you can switch to a narrower 10-speed chain at the expense of chain life. I've messed around, mixed and matched with chains/derailleurs enough (primarily to satisfy my curiosity) to figure out what works and what doesn't

FYI - the max pull (i.e. limit to limit) of the 9 and 10 speed RD's are the same (i.e. both derailleurs move the same distance). The only difference is the 10 speed moves less per shift than a 9-speed.

This may help you a lot:
Bicycles/Maintenance and Repair/Gear-changing Dimensions - Wikibooks, open books for an open world

Bicycles/Maintenance and Repair/Chains/Chain sizes - Wikibooks, open books for an open world

-S


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## Harold (Dec 23, 2003)

The end of this article references a DIY mod to change the actuation ratio of a 10spd rear der. to make it work on a 9spd drivetrain.

Chain Luck Brings "Shadow Plus" Tech to Shimano 9 Speed Equipment - Bike Rumor

I read that the actuation ratio of the 10spd der is not 2:1 like the 9spd Shimano gear. it's more like 1.6:1


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## andy b. (Sep 7, 2010)

SRAM most certainly makes Shimano-compatible shifters, here's one right here. The make both trigger and grip shifters that work.

SRAM Attack Trigger Shifter | SRAM

If you run a 10-speed chain you should be okay with the 9-speed cassette and 10-speed derailleur. The RD isn't "indexed", all it is is a parallelogram with a spring in it. All of the indexing is performed by the shifter.

Andy B.


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## Hiebs915 (Sep 14, 2012)

I've been talking with the dealer I bought my shifters from and it sounds like he will exchange the 9 speed shifter pod for a 10 speed pod. So, I think I'm just going to keep my 10 speed derailleur and buy a 10 speed chain and cassette. 

I don't have a chain or cassette right now so its not a hassle to just go 10 speed.


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## Bataivah (Feb 19, 2011)

Attack is compatable but not as good as the X series shifters. Think about changing the DR pully's with 9 spd ones and keep the shadow,,,maybe


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## Bataivah (Feb 19, 2011)

I just dont see any need for a 10 spd since I never use the larger cogs on my 9 spd as it is. I still like the 7 spd on my vintage bike, but use the 9 spd for the quicker shifting since the cogs I do use (like only 2 or 3) are closer together.


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## shibiwan (Sep 2, 2012)

Hiebs915 said:


> I've been talking with the dealer I bought my shifters from and it sounds like he will exchange the 9 speed shifter pod for a 10 speed pod. So, I think I'm just going to keep my 10 speed derailleur and buy a 10 speed chain and cassette.
> 
> I don't have a chain or cassette right now so its not a hassle to just go 10 speed.


Sounds like a great plan! You'll need a cassette and chain anyways. lol.

-S


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## Bataivah (Feb 19, 2011)

Maybe as all the Granny's out the on the trail keep getting older, they have to keep making ratio's
lower and lower lol!
Well, in hindsight, the very first season I rode on a real trail, I did use the lower gears, but
once I built up some strength to climb and what not, I just dont use them anymore.


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## Hiebs915 (Sep 14, 2012)

Bataivah said:


> Maybe as all the Granny's out the on the trail keep getting older, they have to keep making ratio's
> lower and lower lol!
> Well, in hindsight, the very first season I rode on a real trail, I did use the lower gears, but
> once I built up some strength to climb and what not, I just dont use them anymore.


LoL. I'm only 23 haha. I guess going 10 speed is just easier for me right now. Less modification hassles. Having an extra gear isn't going to hurt anything either.


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## Bataivah (Feb 19, 2011)

Yea I agree. In the future if you ride alot you'll see you wont go as low as you will atm. And I wish I was 23 again!


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## Berkley (May 21, 2007)

Bataivah said:


> Attack is compatable but not as good as the X series shifters. *Think about changing the DR pully's with 9 spd ones* and keep the shadow,,,maybe


Why? This will make no difference whatsoever.


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## Bataivah (Feb 19, 2011)

to match a 9 spd chain width
was only a thought anyway


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## Varaxis (Mar 16, 2010)

10 speed stuff definitely carries a price premium, especially if you're shopping SLX/XT level stuff. Think about what else you can speed your money on that will actually improve your ride, namely your control, comfort, and ability/versatility. You can get quality performance tires, suspension, dropper post, or even a nice wheelset for your bike. Maybe you can get better eyewear, hydration, a rack for your car. You can maybe afford to go on a road trip, maybe with companions, to visit awesome new trails... what does 10 spd give ya? The clutch mech of the Shadow Plus is a relatively big plus, so why not spend just $20 for a chain and $25 for a cassette and get that SRAM shifter and go 9 speed and have money left over to get other things that will lead to more fun, and less likely to leave your bike as a garage queen, since it "needs more customizing".


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## Harold (Dec 23, 2003)

or look into the DIY mod for the derailleur that I posted earlier so you can use your existing shifters. That article was posted just a few days ago, so it's relatively new info.


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## Varaxis (Mar 16, 2010)

I see new holes drilled into the lever arm of that Shadow Plus RD, plus an intricate cable pinch area, plus a 15 Euro cost, plus lots of German, [plus a lot of history of his progression, which impatient plp who don't like to read probably wouldn't make it past, due to lack of understanding or interest]... Probably intimidating to someone in beginner forum who's looking to spend money on SLX/XT stuff, assuming he likes things that work reliably out of the box. Maybe if people you suggested the mod to were old school and knew of stuff like the alternate cable routing for compatibility back in the day... (see this article Mixing Brands of Shifters, Rear Derailers and Cassettes)

Not sure why he insists on Shimano 9 spd shifters, unless he's a brand fanatic. The paddles feel flimsy and oddly shaped compared to the solid/secure and smooth feeling SRAM 9 speed shifter paddles. I dunno, it just seems to be the more simple and elegant thing to do and in my opinion, win-win, since I consider the SRAM 9 speed shifters better. I didn't go back to Shimano until they came out with 10 speed.

Plus there's someone who has commented in that blog post about that little known drivetrain mixing fact, which I detailed a while back. Not sure why people reject what I said outright, finding it inconceivable that a Shimano 10 spd RD cannot have the same cable pull ratio as a SRAM 9 spd shifter, and insisting SRAM and Shimano just simply don't mix.


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## the-one1 (Aug 2, 2008)

shibiwan said:


> *You can't mix and match between SRAM and Shimano rear derailleurs/shifters.* The SRAM uses a 1:1 pull ratio while the Shimano uses a 2:1 pull ratio......................
> -S


You "can" use SRAM 9spd with Shimano 10 spd rear IF you use a 10 spd chain.

I had X9 9spd shifters with SLX 10spd rear and it worked fine until I got a X0 rear dr.


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## Varaxis (Mar 16, 2010)

the-one1 said:


> You "can" use SRAM 9spd with Shimano 10 spd rear IF you use a 10 spd chain.
> 
> I had X9 9spd shifters with SLX 10spd rear and it worked fine until I got a X0 rear dr.


What happened when you used a 9 spd chain? I've seen 10 spd chains jam between RD pulley and cage, even on 10 spd RDs (ex. SRAM XX with a proper 10 spd drivetrain, but that's just a crappy RD), so I've stuck to running 9 spd chains on my 9 spd drivetrains to entirely avoid that problem. Your statement sounds like it's a requirement to use a 10 spd chain, as if 9 spd doesn't work at all.


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## Harold (Dec 23, 2003)

Varaxis said:


> I see new holes drilled into the lever arm of that Shadow Plus RD, plus an intricate cable pinch area, plus a 15 Euro cost, plus lots of German, [plus a lot of history of his progression, which impatient plp who don't like to read probably wouldn't make it past, due to lack of understanding or interest]... Probably intimidating to someone in beginner forum who's looking to spend money on SLX/XT stuff, assuming he likes things that work reliably out of the box. Maybe if people you suggested the mod to were old school and knew of stuff like the alternate cable routing for compatibility back in the day... (see this article Mixing Brands of Shifters, Rear Derailers and Cassettes)
> 
> Not sure why he insists on Shimano 9 spd shifters, unless he's a brand fanatic. The paddles feel flimsy and oddly shaped compared to the solid/secure and smooth feeling SRAM 9 speed shifter paddles. I dunno, it just seems to be the more simple and elegant thing to do and in my opinion, win-win, since I consider the SRAM 9 speed shifters better. I didn't go back to Shimano until they came out with 10 speed.
> 
> Plus there's someone who has commented in that blog post about that little known drivetrain mixing fact, which I detailed a while back. Not sure why people reject what I said outright, finding it inconceivable that a Shimano 10 spd RD cannot have the same cable pull ratio as a SRAM 9 spd shifter, and insisting SRAM and Shimano just simply don't mix.


I've seen beginners do much more complicated things than that relatively simple derailleur mod. You're missing the point that the Shadow Plus 10spd RD does NOT have the same cable pull ratio as SRAM. It's 1.6:1, not a straight 1:1 like SRAM. I haven't used it so I can't say how well it works. But if people are using it and it's okay, the ratios must be close enough that it's not completely impossible. But it's a less elegant solution, IMO, that's begging for trouble.


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## shibiwan (Sep 2, 2012)

the-one1 said:


> You "can" use SRAM 9spd with Shimano 10 spd rear IF you use a 10 spd chain.
> 
> I had X9 9spd shifters with SLX 10spd rear and it worked fine until I got a X0 rear dr.


Really odd... the pull ratios are so different. Did it skip gears during the shift (i.e. 2 gears per click)? Did you do any mod work?

-S


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## Hiebs915 (Sep 14, 2012)

The seller has agreed to give me a 10 speed shifter for the 9 speed one I purchased. I just have to ship the old one back. I'm just going to go 10 speed because I know everything will work well and its only around 50 dollars more if my research on ebay is correct.


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## shibiwan (Sep 2, 2012)

Hiebs915 said:


> The seller has agreed to give me a 10 speed shifter for the 9 speed one I purchased. I just have to ship the old one back. I'm just going to go 10 speed because I know everything will work well and its only around 50 dollars more if my research on ebay is correct.


Excellent OP!!!... but I think you inadvertently touched off another extended philosophical "discussion"..... 

Hope it all works out for you - happy riding!

Cheers!

-S


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## Bataivah (Feb 19, 2011)

shibiwan said:


> Really odd... the pull ratios are so different. Did it skip gears during the shift (i.e. 2 gears per click)? Did you do any mod work?
> 
> -S


Yea, 1:1 shifters with 2:1 dr, wierd it would work properly


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## shibiwan (Sep 2, 2012)

Bataivah said:


> Yea, 1:1 shifters with 2:1 dr, wierd it would work properly


I'm scratching my head too. This is something I had tried just because I had parts lying around to do it and found the Shimano RD would move 2 gears per SRAM shifter click and shifting was pretty much crappy.

Measured the pull on my 10-speed SRAM a little earlier and it moves 3.1mm per click while the X0 RD moved about 3.9mm (10sp spacing = 3.95mm)... so SRAM's 10-speed Exact Actuation is actually around 1.25:1 instead of 1.1:1 (normal SRAM 1:1 setup is actually 1.1:1).

-S


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## Harold (Dec 23, 2003)

shibiwan said:


> I'm scratching my head too. This is something I had tried just because I had parts lying around to do it and found the Shimano RD would move 2 gears per SRAM shifter click and shifting was pretty much crappy.
> 
> Measured the pull on my 10-speed SRAM a little earlier and it moves 3.1mm per click while the X0 RD moved about 3.9mm (10sp spacing = 3.95mm)... so SRAM's 10-speed Exact Actuation is actually around 1.25:1 instead of 1.1:1 (normal SRAM 1:1 setup is actually 1.1:1).
> 
> -S


Ok, that makes a little more sense. If the Shadow Plus RD is 1.6:1 and the SRAM shifter is more like 1.25:1, there's not much of a difference there. fractions of a mm. I could see how it'd work okay, but I could see those fractions of a mm making the setup more fussy and sensitive to adjustment than it might otherwise be.


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## Bataivah (Feb 19, 2011)

I'll run a Shimano cass with my sram der for better shifting, but won't mix sram and shimano shifters and derail even if it did work. I prefer sram shifters myself, anything from X5 to XX. And I'll allways be
2x9 spd or less unless they stop selling 9 spd. If they do stop I'll prolly just go SS and be done with it all lol.


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## Varaxis (Mar 16, 2010)

NateHawk said:


> Ok, that makes a little more sense. If the Shadow Plus RD is 1.6:1 and the SRAM shifter is more like 1.25:1, there's not much of a difference there. fractions of a mm. I could see how it'd work okay, but I could see those fractions of a mm making the setup more fussy and sensitive to adjustment than it might otherwise be.


Where's your 1.6:1 figure coming from? You don't sound so sure yourself.

Seems to me that the 10 speed Shimano Shifter pulls about 2x the amount of cable than the 9 speed Shimano shifter. The Shimano 9 speed shifter cable pull ratio is 2:1 (lots of documentation on that). I'm not certain that it's exactly 2x amount of cable pull per click, but there are sources that have said the same and I can't argue with 'em. That makes it close to a 1:1 ratio, and guess what else is close to a 1:1 ratio?


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## shibiwan (Sep 2, 2012)

Varaxis said:


> Where's your 1.6:1 figure coming from? You don't sound so sure yourself.
> 
> Seems to me that the 10 speed Shimano Shifter pulls about 2x the amount of cable than the 9 speed Shimano shifter. The Shimano 9 speed shifter cable pull ratio is 2:1 (lots of documentation on that). I'm not certain that it's exactly 2x amount of cable pull per click, but there are sources that have said the same and I can't argue with 'em. That makes it close to a 1:1 ratio, and guess what else is close to a 1:1 ratio?


Shimano 2:1 is closer to 1.9:1 on their older stuff and 1.7:1 for their "current" stuff. The pull specs are from here:

Bicycles/Maintenance and Repair/Gear-changing Dimensions - Wikibooks, open books for an open world

Follow the references to the CTC site too - most of the info is there.

I assume Nate's info is off the page documenting the mod - 1.6:1 is not far from 1.7:1 which is the current "Shimano 2:1 standard".

-S

P.S. I updated that wiki page with the SRAM Exact Actuation specs - not sure how far off I am but that's according to what I measured (SRAM X9 10sp Shifter + X0 Type-2 RD + PG1070 cassette)....hope they approve my edits soon.


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## Varaxis (Mar 16, 2010)

I see. Interesting stuff. Gonna be looking through that.

Edit: lots of flags being triggered in my head, making me question the veracity of the data, and I'm finding myself cross checking all of it with research. It all started with me trying to confirm/deny how it says that there's no distinction between road [10 speed] rear shifting and mtb [10 speed]...

Didn't really learn much except to help confirm that Shimano's "2:1" is 1.7:1 and SRAM's "1:1" is 1.1:1 (and Exact Actuation is 1.25:1) and how that table "checks their work" by multiplying those ratios with measured cable pull, to get movement across the cassette, measured in sprocket pitch. When it matches known sprocket pitch of cassettes of certain brands, it's colored coded, with a code for which cassette it matches up with.

If only that table had another column for Shimano 10 speed MTB Dyna-Sys and that source had info on it. It definitely doesn't have a 1.7 derailleur shift ratio.


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## Bataivah (Feb 19, 2011)

Either way, 2:1 dont match 1:1


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## the-one1 (Aug 2, 2008)

shibiwan said:


> Really odd... the pull ratios are so different. Did it skip gears during the shift (i.e. 2 gears per click)? Did you do any mod work?
> 
> -S


The pull ratios are close enough to make it work on the new Shimano 10spd and old SRAM 9spd.
The reason I said a 10 spd chain was that there is some slight rubbing with 9spd chain. The thinner 10spd chain gets rid of the rub. 
Granted it wasn't perfect but it was workable.


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