I have 8 speed Dura Ace parts that are completely functional and I really do not see the need to"upgrade". I do need a new crankset and was jonesin’ after some of the new carbon jobs, but they are for 9/10 speeds. Any way I can get them to work together?
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.
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!
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!
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
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.
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!
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.
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…
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.
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.)
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!
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.
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.
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.