# Can I use 10 speed cranks with my 9 speed drive train?



## wwb159

I have a 2002 model steel bike with shimano 105 9 speed drive train. Recently bought a 2007 TCR Advanced frame, and was given a FSA SLK 10 speed crankset/BB. I want to build the TCR with these components but I'm getting conflicting stories on whether the 10 speed cranks/chainrings will work with 9 speed. LBS says no way, a 9 spd chain wont work at all on 10 speed chainrings. Info I got from this forum says they will work, but I may need to buy 0.6 mm shims to space the chainrings to 9 speed dimensions. Is my LBS right or wrong?


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## PJ352

wwb159 said:


> I have a 2002 model steel bike with shimano 105 9 speed drive train. Recently bought a 2007 TCR Advanced frame, and was given a FSA SLK 10 speed crankset/BB. I want to build the TCR with these components but I'm getting conflicting stories on whether the 10 speed cranks/chainrings will work with 9 speed. LBS says no way, a 9 spd chain wont work at all on 10 speed chainrings. Info I got from this forum says they will work, but I may need to buy 0.6 mm shims to space the chainrings to 9 speed dimensions. *Is my LBS right or wrong?*


Wrong, per Sheldon Brown:
*New Chainrings, Old Chains*
http://www.sheldonbrown.com/speeds.html#chainrings

And even if you were to experience the problem described, just opt for a 10 spd chain. It'll work fine with your 9 spd cassette.


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## RickB.

No problem on my bike. Been using 10 spd crank/rings with 9 spd everything else for over a year...


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## matchmaker

wwb159 said:


> I have a 2002 model steel bike with shimano 105 9 speed drive train. Recently bought a 2007 TCR Advanced frame, and was given a FSA SLK 10 speed crankset/BB. I want to build the TCR with these components but I'm getting conflicting stories on whether the 10 speed cranks/chainrings will work with 9 speed. LBS says no way, a 9 spd chain wont work at all on 10 speed chainrings. Info I got from this forum says they will work, but I may need to buy 0.6 mm shims to space the chainrings to 9 speed dimensions. Is my LBS right or wrong?


Chainrings are chainrings, they will work with virtually any chain. The spacing between them may effectively limit certain gear combinations though, so those 0.6 shims are a good idea. 

I have done the same thing: 10 speed cranks on a 9-speed bike and I used the shims to install. Haven't had any problem with them and shifting is excellent.

So just use the 10-speed crank with the shims and you will be fine.


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## wwb159

Thanks Guys. I'm out to the garage to build it...


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## baldmanrunning

matchmaker said:


> Chainrings are chainrings, they will work with virtually any chain. The spacing between them may effectively limit certain gear combinations though, so those 0.6 shims are a good idea.
> 
> I have done the same thing: 10 speed cranks on a 9-speed bike and I used the shims to install. Haven't had any problem with them and shifting is excellent.
> 
> So just use the 10-speed crank with the shims and you will be fine.


Do you get those shims from the LBS? I have this exact issue. Thanks!


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## JoelS

This question comes up a lot.

My wife is running a 10sp crank with an otherwise 9sp drivetrain. It's been like that well over a year now. No problems.


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## baldmanrunning

JoelS said:


> This question comes up a lot.
> 
> My wife is running a 10sp crank with an otherwise 9sp drivetrain. It's been like that well over a year now. No problems.


 My drivetrain is getting more frankensteined by the day. It was a 9 speed triple (52/42/30) Tiagra... I've swapped out the cranks for a 10 sp standard double (53/39), and the FD for a Dura Ace 7900 (I think... could be 7800?). I can't go into the small-small combinations (34 x anything below 14 on my 11-25 cassette), and I can't go big-big either (53 x anything over 14 on the cassette). It's workable, but annoying. Still using my 9 sp chain and my long-cage Tiagra RD. I think the shims would help, at least somewhat. Probably ought to get a shorter-cage RD and a new chain too.


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## matchmaker

baldmanrunning said:


> Do you get those shims from the LBS? I have this exact issue. Thanks!


I got mine from bikeman, but they appear to be out of stock. I am pretty sure I used the 0.6mm ones, like these http://cgi.ebay.com/0-6mm-Alloy-Cha...t=LH_DefaultDomain_0&hash=item3cb3024865#shId. I think some places sell them in bags of 10.


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## frpax

Yes you can do it. Your crank doesn't care how many gears you run in the back.


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## TomH

If you looked around that lbs, they probably had a whole fleet of 9 speed bikes with 10 speed cranks installed, spec'd by the manufacturer.


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## baldmanrunning

matchmaker said:


> Chainrings are chainrings, they will work with virtually any chain. The spacing between them may effectively limit certain gear combinations though, so those 0.6 shims are a good idea.
> 
> I have done the same thing: 10 speed cranks on a 9-speed bike and I used the shims to install. Haven't had any problem with them and shifting is excellent.
> 
> So just use the 10-speed crank with the shims and you will be fine.


Can anyone who has these shims measure them and tell me the dimensions exactly? I was wondering if standard washers from the hardware store could suffice if I could get the right size...


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## matchmaker

baldmanrunning said:


> Can anyone who has these shims measure them and tell me the dimensions exactly? I was wondering if standard washers from the hardware store could suffice if I could get the right size...


0.6 mm thick, the other part is that they have to fit around your crank bolt, but you can test that in practice. Hope this helps.


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## jtdimas

I'm dealing with this now to run a Shimano 5703 crank set with a 9 speed Shimano 105 drive train. Did you install the shims between the outer chain ring and the spider and the smallest chain ring and the spider? (That would seem to me to provide even spacing to accommodate a 9 speed chain.) If so, does that make enough difference in your chain line to worry about?


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## Guest

matchmaker said:


> 0.6 mm thick, the other part is that they have to fit around your crank bolt, but you can test that in practice. Hope this helps.


 
Thread dredge. Can someone confirm that .6mm is the correct thickness of washer needed? Would I need two, one on each side of the spider? Thanks.

EDIT: Here is a source for numerous chainring spacers, Wheels Mfg Chainring Spacers


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## Blue CheeseHead

or get them on Amazon for less than $10.

Amazon.com : CHAINRING SPACERS OR8 SS 0.6mm SL BGof20 : Bike Chainrings And Accessories : Sports & Outdoors


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## Guest

Thanks for extra link, BCH. This thread is the only place in all my searching that gives the thickness of spacer needed, and I wonder where the OP got this info.


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## Guest

Drew Eckhardt said:


> My FSA Carbon Pro Compact "9 and 10 speed compatible" crank set had no usable overlap between rings (chain rub on the big ring with the three smallest cogs) until I spaced it out to 9-speed dimensions after measuring with my dial calipers and finding the rings closer than Campagnolo 10 speed.
> 
> Wheels Manufacturing and LeTour both sell .6mm spacers specifically for this purpose; you can get them at Branford Bike.


Found a post by a long-time member who's used the .6mm shims, so that's enough confirmation for me to give it a try.


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## Jay Strongbow

frons said:


> Found a post by a long-time member who's used the .6mm shims, so that's enough confirmation for me to give it a try.


I've only read the recent posts and don't exactly know what's being discussed here, but I saw you linked to Wheels so if there's still any doubt you could try asking them. Presumably they know what uses they're building and selling stuff for.


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## Guest

Jay Strongbow said:


> I've only read the recent posts and don't exactly know what's being discussed here, but I saw you linked to Wheels so if there's still any doubt you could try asking them. Presumably they know what uses they're building and selling stuff for.


I may do that but thought I'd get a faster answer here. I also checked out the Branford Bike site Drew mentioned. The Le Tour shims are still on that site for sale along with this information that may or may not be Campy specific:


> 0.6mm spacers are ideal for retrograding Campagnolo 10 speed chain rings for use with 6,7,8 and 9 speed Campagnolo drivetrains.
> 
> Simply place a 0.6mm spacer the BACK of the outer chain ring. If you have a Record 10 speed chain ring remove and discard the .4mm Campy spacer that sits between the FRONT of the ring and the crank arm.



I wonder if the use of only one shim and its placement applies to Shimano cranks, as well? I can't seem to find any measurements posted for Shimano cranksets, so I may work with my LBS to take measurements of what I have (DA-7700 FD and 105 5600 crank). My previous 9-speed crank used a different BB so it would not transfer to my new frame.


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