No.

Also. There is no such thing as a "9/10" speed chain ring despite manufacturers claims. A chinaring is either 8, 9 or 10 speed, "A", "B" or "C" series.

Mixing them may "work" by some people's definition, but I would not sell it as acceptable being a retailer.

The devil is in the details. A truly 10 speed chainring is narrower than a 9 speed (and much narrower than an 8 speed) chainring since all the drivetrain components, including chain and cogs, are narrower too.

The "9/10 speed compatible" chainrings we received from two manufacturers were prone to difficult front shifts and odd chain wear. We phoned one of the manufactureres and asked them, "Are these really 10 speed compatible?" Their reply was: "We have had reports of problems...."

John Cobb posted on this forum that he machined .010" from the back of these "9/10" speed compatible chainrings. We did that. It worked better- but still not perfect.

If you use Shimano Dura-Ace 10 speed specific chainrings as the stndard for what "works" (or for that matter, Campagnolo Record 10, which has been around longer)- then no, nothing else really works correctly compared to those.

If you are willing to accepts degrees of compatibily, i.e., 80% compatibilty with advanced chain wear and missed shifts/dropped chains- then yeah, they are all compatible with each other.

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Tom Demerly
The Tri Shop.com

Nah , I prefer function over fashion so I guess I 'll shop for the ol' tried and true aluminum cranks.

Thank for the quick reply!

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Tom, knows his stuff, I trust him and I'd never say he was wrong. That being said, I mix 7-8-9 speed parts all the time. It takes abit of adjusting but can be done. I've not seen any excessive chain wear or dropped chains. But then again, I'm a bike mechanic and do all my own work. I work on my bikes between each ride so i avoid many problems that non-mechanic users see. If you don't normally work on your bike weekly.....then I would not mix parts. The der. have to be adjusted each time you change form 7-8-9 speeds. This includes der. limits as well as tension.

I've had a few friends that switched to carbon cranks and then back to DA. They didn't like the carbon ones! I've been running 8 speed DA/Ultegra parts for 13 years and see no reason to change. Yep...the carbon cranks look nice but you'll gain nothing.

BTW- I know absolutely nothing about the 10 speed stuff other then its very expensive!

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Paul

Paul thanks for the reply, I appreciate both of the points of view that you and Tom have given. I as well understand what you are saying about DA's durability as I just cashed in my beloved 7400 crank that had to have 50, 000 miles on it and the sad thing is is that it still worked great. I sold it mostly for cosmetic reason...kinda beat up and tarnished but still functioned without a flaw.

I want carbon cranks strictly for cosmetic reasons but as I said , I do not want to sacrifice the functionality that I have learned to appreciate using DA.

So are you saying that if I make the switch to carbon cranks, or Al 9/10 speed cranks for that matter, that I can one; get it to function and two; it will remain reliable as long as I do not try to swap parts after the 9/10 crank is dialed in?

Right now my intention is one bike with one set of wheels, no swaparoos with 7 or 9/10 wheels, cogs etc.

Whattaya think?

Dennis

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If you run an 8 speed drivetrain, and want to use a 9/10 crank, then use a 9 speed chain and it should work.

It's tom's job to recommend against mixing stuff like this, but realistically i think it'll work fine.

Exactly what Ben said.

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Tom Demerly
The Tri Shop.com

Dennis,

As you increase the number of cogs you decrease the amount of space between the cogs, thus you end up with a thinner chain as you go from 7 speed through ten speed. I've been able to mix 7-8-9 parts. 9 speed cranks and chainrings with 7-8 speed cogs. The only thing that really matters is the number of clicks in the shifter, not the rear der. The other problem becomes the thickness of the chain compared to the spacing of the rear cogs. I have no experience with 10 speed. The chain is VERY narrow. I'll assume that you may be able to use the cranks and rings of 10 speed while using the 8-9 speed chains and rear cogs. This is ONLY a guess!

Warning: I accept no responsibility if this does not work!! : ) Reading this waiver releases me from all the bad sh*t that can happen to you, your equipment, friends, relatives and family as a result of trying the above stuff combined, or separately, including but not limited to injury or death! : )

I'd stick with 8-9 speed cranks!

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Paul

I run 8 speed cogs with 9 speed cranks on most of my bikes and have had no problems, so long as I use a 9 speed chain.

Okay...I have a complete 9-speed Shimano set-up on my 2nd bike....as I've just bought some Rotors I now have the Dura Ace 10-speed crankset to put on this bike.....what would you do?

Buy a 10-speed Dura Ace chain and front derailleur....or just the chain will do? the cassette and rear derailleur are 9-speed.

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Stephen Perera
Gibraltar, Europe
graphics@gibraltar.gi

Actually, come to think of it I have just stuck a Rotor crankset into a 10-speed system...is this okay?

I have the RS4X crankset (incl. 52-39 chainrings) with a 10-speed front derailleur, 10-speed chain, 10-speed cassette, 10-speed rear derailleur.....I also use wheels with 9-speed cassettes.....

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Stephen Perera
Gibraltar, Europe
graphics@gibraltar.gi

Wow, a lot of misinformation here. First of all, if you want the last word, call Shimano tech support--their answers are 90% correct, but 10% of the time they don't even read their own company's literature! Anyway, there is some Shimano-approved combatibility betweeen 8-speed DA and later DA versions (of course, it depends highly on which components you wish to combine). Also, you can look at page 170 in Shimano's 2004 "Trade Sales & Support Manual" to get a good overview of compatibilites.

For example, one thing that few folks know is that Shimano specifically mentions on some of their literature that 9-speed DA STI shifters are completely compatible with their 8-speed DA drivetrain provided that you understand that one index postion (the last 'click' for the biggest rear cog) on the shifter will not be used. But the internal geometry and 'cable-pull' per shift is the same on the 8 and 9-speed DA STI shifters (but not for the 10-speed shifters). I have used this combo for years and my 9-speed STI DA shifters shift flawlessly (through 8-speeds, not 9) on circa 1992 DA 8-speed derailleurs.

But to answer your crank question, if you use Shimano 9-speed cranks with your drivetrain and use an 8-speed chain (NOT a 9-speed chain as others suggest) you will have no problems at all. According to my micrometer, the width of the "chain holding part" of a DA 8-speed chainring is 0.079", while the corresponding width of a DA 9-speed ring is 0.076", a difference of just under 4 % on a part just under 2 mm wide. Lets be realistic here, this is a bike, not a Pentium 4 integrated circuit where nanometers make a difference. I also use DA 9-speed cranks with my 8-speed set-up and it shifts perfectly.

However, if you use an 8-speed front derailleur on the above set up (as I do), it IS quite important to use an 8-speed chain and this is not a guess. Shimano backs this up. Why? Well, the chain is visibly wider than a 9-speed chain and the 8-speed chain will shift better on the front chainrings if you use the very slightly wider 8-speed DA front derailleur. If you want to (or must) use a 9-speed chain, then you should change the front derailleur to a slightly narrower 9-speed DA model to get flawless front shifting.

But none of this applies to DA 10-speed cranks and chains, as I am not sure how wide the chainrings are. And none of this can automatically apply to any off-brand carbon cranks. Quality control and consistency is notoriously variable on other brands, so unless you examine (and preferably measure) their chainrings, it is difficult to say with any certainity what kind shifting results you will get.

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Where would you want to swim ?

I recommend a 9 speed chain because he will be using a 9/10 crank, and they tend to run more towards a narrower spacing. A 9 speed chain will work, some 8 speed chains might not. The rear cog spacings don't really matter.

Also, in response to the front der. sugestions.

He really doesn't have to get a new front der. Depending on what chain he ends up using, he might have to slightly pinch the der. inwards, or spread it slightly outwards.

The 8 speed chain will work fine with 8 cogs in back, but if you slap in a 9 speed rear wheel on occasion like I do (friction shifter), you will have problems.

I repeat that I have had no problems with a 9 speed chain with 8 cogs in back and an 8 speed derailleur.

Yes, there will be no problem in the back, and it will probably work decently in the front. However, according to the shimano tech experts, shifting in front will be less responsive (w/ 9-speed chain in 8-speed front der.)

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Where would you want to swim ?

Any rear der. will work for either 7-8-9 speed systems. The only change would be the inner limit screw so the chain does not drop into the wheel. The rear der. is only a giant spring that is moved by the shifter. It has no bearing on the distance between cogs, but the shifter does!

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Paul

Mr. trainhardorgohome, are you just making this up? Have you actually tried all these different combinations? What info do you base this interesting claim on??

Yes, rear derailleurs are a little like giant springs moved by the shift levers. However, their internal geometries are quite different (although a few are the same). By internal geometries, I mean the no. of mm the pulley cage will move laterally per mm (or fraction of mm) of cable pull. These numbers are quite different.

If you were correct, there would be no way I could use my DA 8-speed derailleur on and 8-speed cassette with a DA 9-speed shifter and yet I can (perfectly) and shimano confirms this.

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Where would you want to swim ?

Does the same rule/argument apply to Campy? I've got Veloce 8 speed on my road bike and was thinking about changing the chainring (52-42 ) to a compact. I've been told by one retailer that the 9/10 chainrings won't work with my Campy 8 speed.

I'm soooo confused......

The shifter determines the amount the der. moves not the der. So, yes.....the 8 speed stuff works with the 9 speed stuff. I think we are saying the same thing, just a different way. The 8-9 speed stuff is so close that they are basically interchangeable. I will admit that I've heard the 10 speed is a bit different, although the cranks and chainrings will work with 8-9 speed from what I've read.

BTW - I've used 7-8-9 speed stuff as interchangeable since 9 speed came out. So, I base all the above info on everyones "real world" expereinces.

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Paul

speaking of mis-information . . . . . .

the center to center cog spacing of shimano 8 speed is 4.8mm, and for shimano 9 it is 4.34mm.

so, the "same shifter with an extra click" notion for 8 to 9 is. . . . . .well, wrong. interestingly, the ' same shifter with an extra click" idea IS (almost) true for 7 to 8 speed, however, as the spacing there is 5.0mm and this is close enuf.

which of course, is not to say gregORD's bike doesn;t work - obviously it does. his experience in this, however, cannot reasonably be expected to be the norm - more clearly, the assertion that 8 and nine are compatible from an indexing perspective is flat out incorrect. the only thing shared between 8 and nine is the axle spacing, and the freehub/cassette bed. essentially, they jammed 9 in where there used to 8. everything cnaged, to make it fit.



none of this matters to the original poster's question, BTW. as ben has noted the front will work fine, perhaps requiring a tweak of a cage. the only real problem up front comes from going the other way - running a too narrow new-school chain on a too wide old-school crank.

anyway, as i was saying . . . an 8 speed shifter will move the derailleur .45 mm too far each shift on a 9 speed cassette. over 5 shifts, then, the derailleur will be 2.35 mm too far past the desired cog, and in fact will be closer to the next cog than it is to the desired "clicked on" cog. hardly interchangeable, eh?

again, note that for 7 to 8 it works well, as even after all 7 shifts you are only 1.4 mm off, and still well under halfway to the next cog.

this can be compensated for by setting the indexing up so the it is dead nuts perfect in the middle of the cassette, and will then deterirorate slowly towards the upper and lower range . . . but not QUITE to the point of 2.35 mm ans so not quite to the point of it actually not working. i suspect this is what gregORd has done. i suspect further that he keeps his cables clean. another trick would be to set it up with a slight small cog bias, and allow the stronger pull of the cable to compensate over the weaker return spring - some derailleurs allow you to strenghten the return spring, and this would be a good idea when trying this. also, this will be more likely to work with an older derailleur, with a more worn yet very clean upper jockey wheel - the slight play ( the patented "centeron" motion ) of the upper jockey will help the mismatch from taking over.

oh, and getting-old is quite right - generally speaking the derailleur itself does not care about any of this. any modern der will work, more or less. an extreme case of this might e something like a 7 spd era campy on a 9 speed shimano set up. i have this working on my daughter's bike, and i have to pick at what end of the cassette i wish it to actually work well. in her case i block out the cogs up to the 14 anyway for junior restrictions, and the remaining ones work OK.

mn_leaf_fan,

I am a Campy equipped bike owner. Blood relative of Record10Ti? My first bike had 8spd, second one had 9spd and third one had 10spd, and later converted the 9spd to 10spd.

Following this thread, one might reasonably expect that as the chain became narrower to accommodate the narrower spacing on 10spd cassettes (Campy 9spd and 10spd cassettes use the same hubs) there would be greater opportunity for the narrower chain (10spd) to "drop" between or get wedged between the chainrings on a 8 or 9spd crankset.

If you are willing to accept the risks of the personal injury that may result from this occurrence, then you may experiment to your heart's content. However, I have knowledge of at least one cycling club member who befell the consequence of his chain getting stuck between his chainrings while climbing. He was only unconscious for approximately 10 minutes. No apparent residual brain damage, but he was a little "different" to start with.

Conversely, as one uses a crankset with narrower chain ring spacing to prevent this opportunity for the chain to wedge between the chainrings, running a wider chain on a crankset with narrow spacing could/would result in shifting problems. Running the compatible narrow chain may eliminate this problem on the crankset, but may cause other mis-shifting problems running on the wider 8spd cassette spacing on the rear.

FWIW.

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Ben Cline


Better to aspire to Greatness and fail, than to not challenge one's self at all, and succeed.

Again, I ask the question: do you guys just make all this up? What do you base your assertions on? Do you even understand how the systems work? Oi!

The reason I ask, is because I base my assertions on what Shimano (who know, the big company that actually MAKES the stuff that we are talking about) prints in their literature or whose employed technical reps have told me in person (or on the phone).

By the way, I am completely aware that the center-to-center cog spacing of shimano 8-speed is wider than for shimano 9-speed. The issue is that the differences in internal derailleur geometry can take care of this when the shifter is also different (see my full explanation above in my original post for all the details).

And if it is "wrong" or "flat out incorrect" to use a Shimano DA 9-speed shifter with a Shimano 8-speed rer der. and 8-speed cogset, you better tell Shimano to revise all their printed literature, because they must have made a big goof in saying they are compatible.

Also, my set up (described in my original post) does not use the method of "setting the indexing up so the it is dead nuts perfect in the middle of the cassette, and then allowing it to deterirorate slowly towards the upper and lower range." Mine is perfect in EVERY cog postion, as Shimano says it will be.

And if "'getting-old' is quite right -- generally speaking the derailleur itself does not care about any of this", how do you know he is quite right? What is this based on? Because Shimano (who know, the big company that actually MAKES the stuff that we are talking about) says he is not quite right at all....

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Where would you want to swim ?

 greg.

tell you what. i have listed the spacing differences, and what they mean. it speaks for itself, and those of us who lived thru it know it to be the case.

whatsay you post a link to this info you claim is out there, which you say contradicts it?