# 10 speed campag shifters with 10 speed shimano deraileur



## sadisticnoob (Dec 6, 2009)

Does the above combination work?


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## bikerjohn64 (Feb 9, 2012)

sadisticnoob said:


> Does the above combination work?


I somehow doubt it. I think the "pull-ratio" of the lever and the derailleur's "actuation ratio" is different.


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## Ventruck (Mar 9, 2009)

Going to what cassette? I've never heard of that one working for either design regardless.


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## Drew Eckhardt (Nov 11, 2009)

Three's a Jtek shiftmate which makes the combination work.


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## sadisticnoob (Dec 6, 2009)

using a shimano cassette 12-25.

shimano shifters replacements are very expensive


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## cxwrench (Nov 9, 2004)

Jtek Engineering Shiftmate

the #3


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## Kontact (Apr 1, 2011)

sadisticnoob said:


> Does the above combination work?


This combination shifts great - on a Shimano 8 speed cassette. But not on a 10 cassette.


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## onespeedbiker (May 28, 2007)

sadisticnoob said:


> Does the above combination work?


Yes, but you would need to go back to a 9 speed cassette. 10 speed Campy shifters with 9 speed Shimano cassette using _hubbub_ cable routing on your Shimano derailleur. This is the most common Campy Shimano marriage. Check it out here Rear Shifting. I also used this setup and the shifting was flawless. :thumbsup: However as the other posters also said, Jtec shiftmate will also do the job. I've used it also with great success. Jtek Engineering Shiftmate


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## PlatyPius (Feb 1, 2009)

Why not just buy SunRace/Microshift shifters? They're cheaper than Shimano or Campy and you don't have to rig anything to make it work.


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## adam_mac84 (Sep 22, 2010)

10s Campag shifters, + SRAM RD ($50 at my LBS), with shimano/sram 10s cassette has worked flawlessly for me for CX/road riding. I have also run 10s Campag with shimano RD 'HUBBUB' to 9s cassette without problems


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## PlatyPius (Feb 1, 2009)

adam_mac84 said:


> 10s Campag shifters, + SRAM RD ($50 at my LBS), with shimano/sram 10s cassette has worked flawlessly for me for CX/road riding. I have also run 10s Campag with shimano RD 'HUBBUB' to 9s cassette without problems


How can that possibly work???

Campy/Shimano pull = 2:1 (roughly)
SRAM pull = 1:1 (roughly)

Campy spacing =/= Shimano spacing on the cassette.

Math sez impossibru!


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## onespeedbiker (May 28, 2007)

PlatyPius said:


> How can that possibly work???
> 
> Campy/Shimano pull = 2:1 (roughly)
> SRAM pull = 1:1 (roughly)
> ...


I first heard about what adam_mac84 is talking about from an article from Leonard Zinn. Can you run Campy shifters with a SRAM drivetrain? Sure, why not? The reason it works is while SRAM pull may be 1:1, the amount a SRAM shifter pulls between clicks is still very similar and in this case the pull between clicks of SRAM and Campy are within .02mm; it is the derailleur that creates the difference in spacing. So, if you switch a Shimano rear derailleur for a SRAM rear derailleur, you can use Camp 10 sp shifters and it work with 10 speed Shimano or SRAM cassettes. I've not done it, but it sounds reasonable to me.


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## Kontact (Apr 1, 2011)

PlatyPius said:


> How can that possibly work???
> 
> Campy/Shimano pull = 2:1 (roughly)
> SRAM pull = 1:1 (roughly)
> ...


Campys are closer to 1.5:1, which is why 10 speed Campy shifters will make a Shimano go 8. The actual comparables are 2.3mm of cable per Shimano 10 shift vs. 2.8 for Campy 10.

Campy 10 is wider spacing than SRAM 10, so when combined with a SRAM derailleur the resulting travel lines up with a SRAM/Shimano 10 cassette.

Math works out fine, if you start with the right numbers. While SRAM made much of their actuation ratio, Campy had learned their lessons from Syncro and had exceeded Shimano's actuation 18 years ago.


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## onespeedbiker (May 28, 2007)

Kontact said:


> Campys are closer to 1.5:1, which is why 10 speed Campy shifters will make a Shimano go 8. The actual comparables are 2.3mm of cable per Shimano 10 shift vs. 2.8 for Campy 10.
> 
> Campy 10 is wider spacing than SRAM 10, so when combined with a SRAM derailleur the resulting travel lines up with a SRAM/Shimano 10 cassette.
> 
> Math works out fine, if you start with the right numbers. While SRAM made much of their actuation ratio, Campy had learned their lessons from Syncro and had exceeded Shimano's actuation 18 years ago.


Interestingly as Zinn also pointed out, both the SRAM and Campy shifters pull about the same amount of cable per click. It's obvious, but an almost counter intuitive reality, that while the actuation ratio may control the overall cable pull, the actual cable pull per click can be designed to any length.


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## C-40 (Feb 4, 2004)

*not quite...*



Kontact said:


> Campys are closer to 1.5:1, which is why 10 speed Campy shifters will make a Shimano go 8. The actual comparables are 2.3mm of cable per Shimano 10 shift vs. 2.8 for Campy 10.
> 
> Campy 10 is wider spacing than SRAM 10, so when combined with a SRAM derailleur the resulting travel lines up with a SRAM/Shimano 10 cassette.
> 
> Math works out fine, if you start with the right numbers. While SRAM made much of their actuation ratio, Campy had learned their lessons from Syncro and had exceeded Shimano's actuation 18 years ago.


Zinn suggest using Campy shifters with all of the other components being SRAM, not with a Campy spaced cassette.

The cable pull numbers do not match up at all. Campy 10 shifters only pull 2.5mm of cable for each of the first five shifts. After those first five shifts, only 12.5mm of cable is pulled, but the SRAM RD needs 15mm of cable pull for five shifts. The RD will be short of travel by almost a full cog, at that point. The next two pulls are the proper 3mm and the last two are 3.5mm. This setup makes no sense. It would be even worse with a Campy cassette.


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## sadisticnoob (Dec 6, 2009)

ok guys i decided to buy a sram rival rear D of ebay to give it a shot.

left the campag shifter 10 speed. does anybody have a spare unused set to sell/give ?

being a college student is bad when replacements are expensive


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## Kontact (Apr 1, 2011)

*Not quite, not quite...*



C-40 said:


> Zinn suggest using Campy shifters with all of the other components being SRAM, not with a Campy spaced cassette.


Try reading again:



> Campy 10 is wider spacing than SRAM 10, so when combined with a SRAM derailleur the resulting travel *lines up with a SRAM/Shimano 10 cassette*.


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## C-40 (Feb 4, 2004)

*still wrong...*



Kontact said:


> Try reading again:


OK. "NEWS FLASH: I put Centaur Ergopower levers on my SRAM Red-equipped bike and have been riding it happily ever since with nary a hiccup in the shifting. I have a SRAM 10-speed chain, SRAM Red chainrings, SRAM Red front derailleur, SRAM Red rear derailleur, and SRAM Red 10-speed cogset mated with the Centaur 10-speed Ergopower levers."

There's nothing about a Campy cassette in that statement. Even if there was, apparently you didn't understand what I wrote. This setup produces inadequate RD travel for a closer-spaced Shimano/SRAM cassette. Changing to a Campy cassette would only make the problem worse, since Shimano spacing is 3.95mm and Campy is 4.12mm.

There is nothing mysterious about cable pulls and RD actuation ratio. Since a since a SRAM RD requires a uniform cable pull of 3mm to move the RD 3.95mm, the actuation ratio is 3.95/3 = 1.32. If a Campy shifter is used, it will only move the RD 3.3mm the first five times, for a total of 16.5mm. It should move the RD 19.75mm, so the location will be off by 3.25mm or 82%, relative to the 6th cog. 

The only way this can work at all is to fudge on both the first cog position and the cable tension in an effort to get the RD further to the left. There is no way that the shifting will be perfect. If a Campy cassette was used, the situation would be far worse.


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## Kontact (Apr 1, 2011)

C-40 said:


> OK. "NEWS FLASH: I put Centaur Ergopower levers on my SRAM Red-equipped bike and have been riding it happily ever since with nary a hiccup in the shifting. I have a SRAM 10-speed chain, SRAM Red chainrings, SRAM Red front derailleur, SRAM Red rear derailleur, and SRAM Red 10-speed cogset mated with the Centaur 10-speed Ergopower levers."
> 
> There's nothing about a Campy cassette in that statement. Even if there was, apparently you didn't understand what I wrote. This setup produces inadequate RD travel for a closer-spaced Shimano/SRAM cassette. Changing to a Campy cassette would only make the problem worse, since Shimano spacing is 3.95mm and Campy is 4.12mm.
> 
> ...


I have no idea what you are arguing about. 

You corrected me because you thought I suggested using a Campy spaced cassette. I didn't . I can't even see why you thought I said that, or why you persist in correcting me about it.

If you are arguing that what Zinn published is a lie, take it up with Zinn. 



But you did get me thinking, so I went and measured the cable pull on my Rival bike. It isn't 3mm, which is probably why you are having a stroke about this. My very simple measures showed about 8.5mm for 3 clicks, or 11.5 for 4 and 16.9 for 6. That's about 2.83mm, just from my eyeball. If my measuring was off by 0.6mm at 6 clicks, that would put the SRAM cable pull at 1.46, just a hair off Campy's 1.48. 

It is definitely not 3mm, so where did come up with that factoid gem?


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## onespeedbiker (May 28, 2007)

C-40 said:


> OK. "NEWS FLASH: I put Centaur Ergopower levers on my SRAM Red-equipped bike and have been riding it happily ever since with nary a hiccup in the shifting. I have a SRAM 10-speed chain, SRAM Red chainrings, SRAM Red front derailleur, SRAM Red rear derailleur, and SRAM Red 10-speed cogset mated with the Centaur 10-speed Ergopower levers."
> 
> There's nothing about a Campy cassette in that statement. Even if there was, apparently you didn't understand what I wrote. This setup produces inadequate RD travel for a closer-spaced Shimano/SRAM cassette. Changing to a Campy cassette would only make the problem worse, since Shimano spacing is 3.95mm and Campy is 4.12mm.
> 
> ...


First it is really hard to get accurate cable pull numbers. SRAM advertises 3mm of uniform cable pull which is suspect, many think it's lower but SRAM wants to differentiate themselves from Campy in this regard (how can you tout 1:1 actuation when your cable pull is the same as a competitor?) . I have also heard that a Campy 10 shifter pulls 2.5mm of cable five times, 3mm twice and 3.5mm twice; averaging 2.8. Regardless The issue here is do SRAM and Campy 10 speed shifters have the same cable pull. Your actuation numbers here are may be irrelevant, because they may not be based on accurate cable pull numbers. What Zinn said was simple, that SRAM and Campy have cable pulls similar enough that they can be switched; that the difference in cog spacing is made up by the derailleurs, not the shifters. 



> I did measure the difference in cable pull between SRAM and Campy 10-speed shifters. Nine clicks of a Campy lever pulls 27.0mm of cable, or 3mm per click. Nine clicks of a SRAM lever pulls 27.9mm, or 3.1mm per click. Jtek’s adapter may adjust for this minuscule difference, but in my experience, it works perfectly with no adapter.


I don't know if this is right and while many have argued against it theoretically, none that I have read have said they tried it and it didn't work.


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## onespeedbiker (May 28, 2007)

Kontact said:


> I have no idea what you are arguing about.
> 
> You corrected me because you thought I suggested using a Campy spaced cassette. I didn't . I can't even see why you thought I said that, or why you persist in correcting me about it.
> 
> ...


Campy 10 speed cable pull averages out to 2.8, which would seem to vindicate Zinn..


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## Kontact (Apr 1, 2011)

onespeedbiker said:


> First it is really hard to get accurate cable pull numbers. SRAM is said to move 3.1mm of cable, but others believe it is closer to 3mm. I have also heard that a Campy 10 shifter pulls 2.5mm of cable five times, 3mm twice and 3.5mm twice; averaging 2.8. Regardless The issue here is do SRAM and Campy 10 speed shifters have the same cable pull. Your actuation numbers here are may be irrelevant, because they may not be based on accurate cable pull numbers. What Zinn said was simple, that SRAM and Campy have cable pulls similar enough that they can be switched; that the difference in cog spacing is made up by the derailleurs, not the shifters.
> 
> 
> 
> I don't know if this is right and while many have argued against it theoretically, none that I have read have said they tried it and it didn't work.


I tried to find where he came up with those numbers, and just find him on other forums telling people that this is all a fairy tale. Here's more "hocus" for C-40:

Rear Shifting

Of note is that Shimano's cable pull for 10 speed is 2.3, not the near 2.8mm C-40 blindly believes it is. Which is why he doesn't believe in the Campy 10 to Shimano 8 trick, or the Easter Bunny.

There is much to be said for doing, especially when reality intrudes on one's "knowledge".


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## Kontact (Apr 1, 2011)

onespeedbiker said:


> Campy 10 speed cable pull averages out to 2.8, which would seem to vindicate Zinn..


The easiest way to vindicate Zinn is to simply hook it up and try. Sounds like lots of people have done just that.

I haven't, but I can measure cable travel.


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## onespeedbiker (May 28, 2007)

Kontact said:


> I tried to find where he came up with those numbers, and just find him on other forums telling people that this is all a fairy tale. Here's more "hocus" for C-40:
> 
> Rear Shifting
> 
> ...


Yes, I edited my last post to include "SRAM advertises 3mm of uniform cable pull which is suspect, many think it's lower but SRAM wants to differentiate themselves from Campy in this regard (how can you tout 1:1 actuation when your cable pull is the same as a competitor?)". As I said before, every person that has tried this says it works great. Only those that try to dis-prove it theoretically insist it won't. My guess is even Zinn's figures are a little off and the accumulated tolerances are less than the .9 mm he claims.


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## Kontact (Apr 1, 2011)

onespeedbiker said:


> Yes, I edited my last post to include "SRAM advertises 3mm of uniform cable pull which is suspect, many think it's lower but SRAM wants to differentiate themselves from Campy in this regard (how can you tout 1:1 actuation when your cable pull is the same as a competitor?)". As I said before, every person that has tried this says it works great. Only those that try to dis-prove it theoretically insist it won't. My guess is even Zinn's figures are a little off and the accumulated tolerances are less than the .9 mm he claims.


SRAM does not advertise any of this stuff accurately. Shimano's actuation is 1.7:1, not the 2:1 they claim. The closest thing to 2:1 was Dura Ace 7400 at 1.92:1. SRAM's old mountain system wasn't quite 1:1 either. 1.1:1 is closer.

Does SRAM stuff even say "1:1" anymore? I thought they started calling everything "Exact Actuation" when the road stuff came out.


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## onespeedbiker (May 28, 2007)

Kontact said:


> SRAM does not advertise any of this stuff accurately. Shimano's actuation is 1.7:1, not the 2:1 they claim. The closest thing to 2:1 was Dura Ace 7400 at 1.92:1. SRAM's old mountain system wasn't quite 1:1 either. 1.1:1 is closer.
> 
> Does SRAM stuff even say "1:1" anymore? I thought they started calling everything "Exact Actuation" when the road stuff came out.





> When we launched our road technology from scratch we reapplied our MTB proven SRAM 1:1 actuation ratio (shifter cable travel : derailleur movement) for 10 speed rear shifting. EA helps to simplify/stabilize the uneasy act of balancing rear derailleur hanger design, tight cog spacing and exact cable tension. The result: the easiest index shifting system to set up and it stays that way.


Exact Actuation | SRAM

I read this 5 times and still have no idea what it means; and the graph didn't help


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## Kontact (Apr 1, 2011)

onespeedbiker said:


> Exact Actuation | SRAM
> 
> I read this 5 times and still have no idea what it means; and the graph didn't help


I believe the point they are trying to make is that the big curved ramp the cable runs on under the derailleur insures that each the derailleur moves a fixed amount of distance for a given amount of cable.

I would assume that all other derailleurs have a slightly more curved graph because the cable is pulling in a straight line, but the parallelogram moves in curve. Kind of like how a bow gets shorter from the first amount of pull.


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## cathyandrob (Jun 15, 2006)

*I tested this set up*

I am planning a bike for touring the Alps this year, so I tested before committing and buying all the parts.

Bought an Apex RD, put it on my Campy 10s bike, installed an old Shimano back wheel and 10s cassette, and took it for a spin.

Seemed to shift just fine, it may not have been perfect but, then again, the only bike that shifts close to perfect to me is my Campy 8 speed. Felt about the same as my Athena 11s and my other Campy 10s bikes.

Planning a disc cross frame, set up for road with 34-32 low gear to help my weak legs get me up the Stelvio in July. Will let you know how it goes.

Rob


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## C-40 (Feb 4, 2004)

Kontact said:


> I have no idea what you are arguing about.
> 
> You corrected me because you thought I suggested using a Campy spaced cassette. I didn't . I can't even see why you thought I said that, or why you persist in correcting me about it.
> 
> ...


You stated: "Campy 10 is wider spacing than SRAM 10, so when combined with a SRAM derailleur the resulting travel lines up with a SRAM/Shimano 10 cassette." 

I'm sorry, but that confused me, since the Campy cassette spacing has nothing to do with the issue. It's all about cable pull of the two shifters and nothing else, since a Shimano/SRAM casette is being used. 

SRAM advertises the 3mm uniform cable pull. Zinn measured it to be 3.1mm, but he also measured the Campy pull to be slightly greater than it really is. I've asked other SRAM owners to measure the pull and got reports of 3mm also.

As a mechanical engineer who's worked in precision metal machining for many years, I know how to make a precise measurement. I've measured the Campy pulls many times and always get the same thing. 

It is not the average pull that matters, when those first five pulls are so far short of the needed amount. I clearly stated what the RD travels should be, with those first five cable pulls. Each one will come up short and the error accumulates to a substantial shortfall. 

To make this setup work decently, you'd need to align the RD a little to the left of the first cog, when it's resting on the small cog limit screw and apply more than normal cable tension to improve the RD alignment on the middle cogs, where it will come up short. Without those special measures, you will have a severe misalignment on the middle cogs.


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## onespeedbiker (May 28, 2007)

Kontact said:


> I believe the point they are trying to make is that the big curved ramp the cable runs on under the derailleur insures that each the derailleur moves a fixed amount of distance for a given amount of cable.
> 
> I would assume that all other derailleurs have a slightly more curved graph because the cable is pulling in a straight line, but the parallelogram moves in curve. Kind of like how a bow gets shorter from the first amount of pull.


Well, if SRAM explained it like that it would certainly make more sense. Thanks


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## danl1 (Jul 23, 2005)

Kontact said:


> I believe the point they are trying to make is that the big curved ramp the cable runs on under the derailleur insures that each the derailleur moves a fixed amount of distance for a given amount of cable.
> 
> I would assume that all other derailleurs have a slightly more curved graph because the cable is pulling in a straight line, but the parallelogram moves in curve. Kind of like how a bow gets shorter from the first amount of pull.


That's it exactly. Because of the parallelogram / single cable attachment point design, a normal RD moves differently across it's range in response to a given cable pull. But because SRAM uses a cable guide (rather like a segment of a pulley around the parallelogram's axis) they achieve equal amounts of guide pulley displacement for given cable pulls across the range.

The actual pull ratio was 1:1 for the old MTB stuff; not sure if it still is. They never used 1:1 for the road, but did use the same linear-response concept.


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## Tucson_2011 (Nov 10, 2011)

Interesting thread, I have experimented a lot with combining different parts and it works perfectly, works sorta, and doesn't work consistently in every gear depending on the combinations. Even made my own "Shiftmate" and it took me two tries to get the right diameter. Varied the cable housing length, thickness and "kink" for the rear derailleur too. Wish I had some of the numbers thrown around in this post when I was doing it, but glad to have them now because I am sure I will need them one day. The bit about the "first five clicks" distance being different than the others really makes sense to what I have seen, and it is hard to jerry-rig around that.


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## C-40 (Feb 4, 2004)

Kontact said:


> I tried to find where he came up with those numbers, and just find him on other forums telling people that this is all a fairy tale. Here's more "hocus" for C-40:
> 
> Rear Shifting
> 
> ...


Campy 10 cable pull averages 2.8mm. I know quite well that Shimano 10 cable pulls average 2.3mm. What relevance does that have to the SRAM/Campy mix?

Yes, Shimano 8 cable pull averages 2.8mm and a Campy 10 shifter will work with that drivetrain. Shimano 9 cable pulls also correspond well with Campy 11 shifters, so you can use Campy 11 shifter with a Shimano 9 drivetrain.

The reason that Campy and Shimano mixtures work well when the average pulls are nearly the same is because both brands use nonuniform cable pulls that increase toward the larger cogs.


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## Kontact (Apr 1, 2011)

danl1 said:


> That's it exactly. Because of the parallelogram / single cable attachment point design, a normal RD moves differently across it's range in response to a given cable pull. But because SRAM uses a cable guide (rather like a segment of a pulley around the parallelogram's axis) they achieve equal amounts of guide pulley displacement for given cable pulls across the range.
> 
> The actual pull ratio was 1:1 for the old MTB stuff; not sure if it still is. They never used 1:1 for the road, but did use the same linear-response concept.


The MTB stuff was 1.1:1. The 2:1 vs. 1:1 one thing was always marketing - no groups ever had those ratios.


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