# Will a 10 speed compact crank work with a 9 speed group?



## dasho (Apr 8, 2002)

I have a 9 speed DA group on my 2002 LOOK.

I would like to change out the 53-39 to a 50-34 compact.

Shimano has an R700 compact and at least one other model but they are for 10 speed groups.

Will the crank work on my 9 speed?

If so, will I need to run a 10 speed chain?

Any advice such as difference between models etc. would be greatly appreciated.

Thanks in advance!


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## PJ352 (Dec 5, 2007)

dasho said:


> I have a 9 speed DA group on my 2002 LOOK.
> 
> I would like to change out the 53-39 to a 50-34 compact.
> 
> ...


The R700 will work fine with your 9 spd group, but you'll have to continue to use a 9 spd chain. 10 spd chains aren't compatible with 9 spd cassettes.


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## vortechcoupe (Jun 6, 2006)

above post is incorrect. On my wife's old bike she had full ultegra 9 speed, changed to a 10sp R600 or the R700 compact and the 9sp chain would catch on the shift pins of the big ring if she was 3-4 from the bottom out back, any further down the cassette and it would just try and shift into the big ring. So i bought a 10 speed ultegra chain and it worked great. Prob got 1000 miles on that setup, no dropped chain or over shifting off the big ring etc..

Oh and i also used a sram 10 speed chain on a other wise full DA 9 speed setup. So I would say a 10 speed chain is compatible with a 9 speed cassette. 

Just a guess but the cogs themselves might be the same thickness, just the spacing might be closer together.


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## PJ352 (Dec 5, 2007)

vortechcoupe said:


> above post is incorrect. On my wife's old bike she had full ultegra 9 speed, changed to a 10sp R600 or the R700 compact and the 9sp chain would catch on the shift pins of the big ring if she was 3-4 from the bottom out back, any further down the cassette and it would just try and shift into the big ring. So i bought a 10 speed ultegra chain and it worked great. Prob got 1000 miles on that setup, no dropped chain or over shifting off the big ring etc..
> 
> Oh and i also used a sram 10 speed chain on a other wise full DA 9 speed setup. So I would say a 10 speed chain is compatible with a 9 speed cassette.
> 
> Just a guess but the cogs themselves might be the same thickness, just the spacing might be closer together.


Sorry, but I beg to differ, the info I provided is correct. 

From the info you provide I can't say what the specific problem was in your wife's case, but I suspect there were other issues at play (cross chaining?). 

I stand by the previous advice re: 9/ 10 spd chain compatibility as well, but I'm glad your set up works for you. And yes, the spacing is narrower on 10 spd cogs, thus the narrower 10 spd chain.


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## vortechcoupe (Jun 6, 2006)

I know what the problem was in my wifes case, the wider 9 speed chain was catching on the closer spaced 10 speed rings.

Your "info" is not correct, you say "it's not compatible". We both rode our bikes with a 10 speed chain and a 9 speed cassette. Not sure what wasn't "compatible" about that. Bike didn't explode!! chain didn't lock up, not shift etc..


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## PJ352 (Dec 5, 2007)

vortechcoupe said:


> I know what the problem was in my wifes case, the wider 9 speed chain was catching on the closer spaced 10 speed rings.


Then quite possibly the chainline was incorrect, and/ or she was cross chaining. Or, had you set it up correctly, the 9 spd chain would have worked.


vortechcoupe said:


> Your "info" is not correct, you say "it's not compatible". We both rode our bikes with a 10 speed chain and a 9 speed cassette. Not sure what wasn't "compatible" about that. Bike didn't explode!! chain didn't lock up, not shift etc..


Great! I'm glad it worked for you, but it's not... recommended. (Or compatible). 

RE: SRAM chains, I have no experience, so I cannot comment.


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## PJ352 (Dec 5, 2007)

Just curious. Did you use an SRAM 9 spd chain with your wifes 9 spd set up when you had the problems?


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## vortechcoupe (Jun 6, 2006)

Why do you want to believe it won't work? It was a shimano ultegra chain. The chain line was perfect, and like i said in my 1st post, when she was in the 3 or 4th (can't remember exactly) cog from the bottom the chain would start to catch on the shift pins of the big ring and try to shift up. The chain was too wide for the more narrow spaced 10 speed crank/chainrings. So i put on a narrower 10 speed chain and it worked great. When i bought the crankset from the shop one of the mechanics said "hey you'll need a 10 sp chain, the chainrings are too close together", i tried it without but he was right.

Maybe your not seeing what was happening. No amount of setup/adjustment would of helped with the 9 speed chain. It was just physically too thick to run with the narrow spaced chainrings.

A lot of things aren't recommended that work fine in real life (bike related and not). 9 speed rear der not "compatible" with a 10 speed shifter right??? yeah OK!!! 

Explain why a 10 speed chain is not compatible with a 9 speed cassette? Just the cog spacing is different right? so the outer plates of the chain aren't as close to the next cog as they would be in a 10 speed cassette? big deal.

I think it's funny that you say it's not compatible but we ran it without any problems, sure recommended maybe not but i wouldn't say not compatable. I didn't have any ill side effects so it's compatible too me!

But you know all and you are correct. I'm done with this internet argument. I'll read your answers to my questions but i'm not going to post anymore. I gave the OP my opinion and what worked for me (my wife) and you think i'm wrong yet you never saw the bike in question. 

Anyway, dasho, buy the crank, see if it works fine without changing anything else. If you have problems or not please report back either way.


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## PJ352 (Dec 5, 2007)

The reason I asked if it was an SRAM chain on the 9 spd set up was because some are known to be wider than Shimano's. That would have explained the chain catch. If you say that's not the case, then so be it. 

I know you'll disagree with this, but I'm also wondering if your using the SRAM 10 spd chain on the 9 spd cassette might explain why that set up works (if it's wider than Shimano's), because as you say, the 9 spd cassette is wider than the 10. I'd be curious if anyone is running a Shimano 10 spd chain with a 9 spd cassette.

For the record, my questions were attempts to determine the source of our discrepancies - trying to understand the cause, and maybe learn something along the way. I know I don't know all and you quite possibly know more. But all that aside, it appears that the OP has some workable solutions at his disposal. That's all that matters.


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## pdh777 (Oct 7, 2005)

To the OP - General course of approach is to follow JP's advice.

And yes the SRAM chains are a bit wider - I do not use them on my Force set up - KMC works better.


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## Sebastionmerckx (Mar 6, 2008)

vortechcoupe said:


> Why do you want to believe it won't work? It was a shimano ultegra chain. The chain line was perfect, and like i said in my 1st post, when she was in the 3 or 4th (can't remember exactly) cog from the bottom the chain would start to catch on the shift pins of the big ring and try to shift up. The chain was too wide for the more narrow spaced 10 speed crank/chainrings. So i put on a narrower 10 speed chain and it worked great. When i bought the crankset from the shop one of the mechanics said "hey you'll need a 10 sp chain, the chainrings are too close together", i tried it without but he was right.
> 
> Maybe your not seeing what was happening. No amount of setup/adjustment would of helped with the 9 speed chain. It was just physically too thick to run with the narrow spaced chainrings.
> 
> ...


Dude,simmer down. PJ was just trying to be helpful and you must have some pretty thin skin because it seems like you are making a mountain out of a mole hill in his responses.The fact of the matter is he is giving sound advice according to MOST reputable sources. Your situation worked and that's great but in ALMOST all cases, it would not. I like him think you must have been using a ten speed sram chain. Were you ? If so,that's why it worked.


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## dasho (Apr 8, 2002)

*Will I need to get a new BB?*

I currently have the old DA spindled model.

Thanks a lot for your info!


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## PJ352 (Dec 5, 2007)

dasho said:


> I currently have the old DA spindled model.
> 
> Thanks a lot for your info!


I'm guessing you have something like this:
View attachment 169281


Or maybe this:
View attachment 169282


But in either case, you'll need this (BB-5600 or BB-6600 will do):
View attachment 169283


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## vortechcoupe (Jun 6, 2006)

PJ352 said:


> I'd be curious if anyone is running a Shimano 10 spd chain with a 9 spd cassette.


She ran a shimano 10 speed chain and 10 speed compact crank with an other wise 9 speed ultegra bike. Including front derailleur.

I ran a sram 10 speed chain with DA 9 speed and a FSA 9/10 speed compact. This setup wasn't as great shifting in the front as her full shimano bike. Prob due to the 9/10 speed FSA rings. 

One thing i did notice on my bike was that the 9 speed front der is a little too fat to shift a more narrow 10 speed chain. Hard to type but basically cage was too wide, could have it shift great one way or the other, just not both perfectly like on my wifes full shimano. Example, when shifting to the big ring the inner cage pushes the chain up, but since the outer cage was a little too wide for a 10 speed cage it would let it push over the big ring. On the other side shifting to the small ring the outer cage pushes it down and again the inner cage would let the chain drop off the small ring. A narrower 10 speed front der would help since it's made for a more narrow chain. But with all that said it still worked and I rode 1000 plus miles like that. Just had to make slow careful shifts.

Also, a 36 small ring cured 99% of my shifting "problems". Made the tooth gap smaller, easier shifting. FSA rings are not even close to the quality of shimano.


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## vortechcoupe (Jun 6, 2006)

could be octalink too but either way you'll need the above outboard BB.

this was me last night, 

http://xkcd.com/386/


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## Sebastionmerckx (Mar 6, 2008)

vortechcoupe said:


> could be octalink too but either way you'll need the above outboard BB.
> 
> this was me last night,
> 
> http://xkcd.com/386/


You're a funny guy. You just said above you had to shift CAREFULLY using the setup you used. You furthermore stated that sometimes the derailleur would push off if you didn't. I think you also said ok shifting not great but it worked. I don't know about you but I suspect everyone else will agree with me here..........When you spend the type of money we all spend on our gear,we want it to work great not ok . Regardless of what you may THINK,running the chain you were running on her bike and also yours is not optimal for the best results. I'm sure it did work but it definitely doesn't as well as it would with the Correct components. :thumbsup:   :mad2:


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## PJ352 (Dec 5, 2007)

vortechcoupe said:


> this was me last night.
> http://xkcd.com/386/


Me too!!


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## saf-t (Sep 24, 2008)

FWIW, I just put a 10 speed Veloce compact crank on my '88 Miyata,which has a 7-speed freewheel. It works perfectly, with a 9-speed chain........


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## C-40 (Feb 4, 2004)

*Facts..*

Shimano 10 cogs are thinner than 9 speed. (1.6mm versus 1.78mm) but that does not make a 10 speed chain "incompatible" with a 9 speed cassette.

All 10 speed chains are now the same 5.9mm width across the outside. SRAM 10 chains are NOT wider than Shimano. In fact, there are two widths across the inner plates. SRAM and Campy UN are .1mm narrower than KMC, Shimano or Wipperman. The master link from a SRAM 10 chain should not be used with chains from the wider inner plate width group.

Campy 10 cogs are nearly identical in thickness to Shimano 9, but you can use any brand of 10 speed chain you wish, with them. There is lots of clearance between the inner plates for cogs of either width. I've even used the narrowest Campy 11 chain on a Campy 10 cassette, which has the thickest cogs and widest cog spacing (4.15mm).


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## Gall (Feb 6, 2004)

*Problem I had...*

I have a 10 speed compact crank with a 9 speed drive.

I placed a 10 speed 7900 chain on and I could not get the chain to shift from the small ring to the big ring. 

I put a 9 speed chain and it worked perfectly. 

9 speed chains for me!

Gall


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## brblue (Jan 28, 2003)

dasho said:


> I have a 9 speed DA group on my 2002 LOOK.
> 
> I would like to change out the 53-39 to a 50-34 compact.
> 
> ...



Did the same, with the same crank, works ok. My chain is a KMC 72 9 speed.

On the smallest 3 sprockets the chain touches the big ring, but that's partly because it's a compact, and there's a big diameter difference between small and large ring. (I agree, with a narrower chain, there might be problems only on the smallest 2 sprockets.)
however I don't use 34 x 14, 13, 12 so therefore, no need to upgrade the chain.

good luck
br


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## Squidward (Dec 18, 2005)

vortechcoupe said:


> ...changed to a 10sp R600 or the R700 compact and the 9sp chain would catch on the shift pins of the big ring if she was 3-4 from the bottom out back


I had this issue as well on one of my bikes. The crankset was a Truvativ 10-speed compact double and the rest of the drivetrain is 9-speed. I ended up shimming the crankset with 0.2mm worth of shims and this allowed me to use the six largest rear cogs instead of the five largest rear cogs. When it started to rub I would shift to the larger chainring up front and keep going.

I had heard somewhere that using a 10-speed chain on a 9-speed drivetrain would cause the chain to wear out prematurely and fail due to the wider cog thickness and the narrower chain. This was from a posting on a forum somewhere but I cannot find it now. Now that C-40 has shed some light on the issue I will start buying 10-speed chains from now on to use on all of my bikes except for my 7-speed commuter and my 9-speed mountain bike.


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## vortechcoupe (Jun 6, 2006)

curty42082 said:


> You're a funny guy. You just said above you had to shift CAREFULLY using the setup you used. You furthermore stated that sometimes the derailleur would push off if you didn't. I think you also said ok shifting not great but it worked. I don't know about you but I suspect everyone else will agree with me here..........When you spend the type of money we all spend on our gear,we want it to work great not ok . Regardless of what you may THINK,running the chain you were running on her bike and also yours is not optimal for the best results. I'm sure it did work but it definitely doesn't as well as it would with the Correct components. :thumbsup:   :mad2:



Her shifting was perfect, never drop chain, etc.. she actually doesn't like her full DA 10 speed as much as her old 9 speed.

But on my bike it was ride able once i got the derailleur just right. Still wasn't optimal. Your last sentence is correct.


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## Sebastionmerckx (Mar 6, 2008)

vortechcoupe said:


> Her shifting was perfect, never drop chain, etc.. she actually doesn't like her full DA 10 speed as much as her old 9 speed.
> 
> But on my bike it was ride able once i got the derailleur just right. Still wasn't optimal. Your last sentence is correct.


In that sense,I suppose almost everyone that has posted on this topic is correct then. You are correct that it can work but not as well as it could and we are right in that you should use the correct corresponding components for the best possible shifting. Could you please just not be so quick to call people wrong next time and get pissy ?


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## dasho (Apr 8, 2002)

*Now for one more question*

I notice Shimano has a FC-R700 and a newer FC-6650 model. Is there any difference other than cosmetics - would either work on my bike?

Thanks again!


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## PJ352 (Dec 5, 2007)

dasho said:


> I notice Shimano has a FC-R700 and a newer FC-6650 model. Is there any difference other than cosmetics - would either work on my bike?
> 
> Thanks again!


The FC-R700 is considered non-series and (for whatever reason) isn't listed on Shimano's North American site, so here's a link to the EU site. Once there, click "*compare*" and from the drop down, choose FC-R700. 
http://cycle.shimano-eu.com/publish...ra/product.-code-FC-6650-S.-type-fc_road.html


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## brblue (Jan 28, 2003)

dasho said:


> I notice Shimano has a FC-R700 and a newer FC-6650 model. Is there any difference other than cosmetics - would either work on my bike?
> 
> Thanks again!


I think all "compact" and shimano, hollowtech 2, cranksets will have the same parameters regarding compatibility with a given frame. 
I don't know about the tech specs for the 6650 (too lazy to browse the web) but I remember it being a bit more expensive, throughout the 'bay deals. And the FC-R700 being "ultegra level" is way good enough for me.

good luck
brblue

PS. The weightweenies listings show the 6650 at 811g together with BB, while the FC-R 700 is shown at 870g with BB.


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