# 11s chainrings on 10s cranks



## joeyb1000 (Feb 15, 2011)

I have 2008 UltraTorque cranks. I want to convert to 11s chainrings. The Campy "Spare Parts" page says that current 11s chainrings are not compatable with pre-2010 cranks. Is that true?


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## bikerjulio (Jan 19, 2010)

No personal experience, and as we know "not compatible" may or may not mean what it says. The rings are a little thinner, so the shim behind the crank would have to change.

If you just want to convert to 11-spd, leave the crankset as is. An 11-spd chain will work. When 11-spd first came out there were several people who just swapped levers cassette and chain and reported it worked fine. RD too with a little tinkering.


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## C-40 (Feb 4, 2004)

*probably...*

The issue may be the relationship between the crank spider's mounting surface and the single surface on the back of the crank arm. Campy made the chainring mounting lugs thinner for 11 speed (about .6mm), but that did not change the tooth to tooth spacing, or the 43.5mm chainline.

I suspect that using 11 speed rings would result in some sort of mismatch. If the mismatch leaves a gap between the crankarm and the chainring, that would be easy to fill with a shim washer, but if it's the opposite, then the crankarm surface would required a precise amount of material to be removed.

I had no problem at all, using 10 speed chainrings with 11 speed. It's not a change that you must make. There is a little difference in the tooth thickness, however. 11 speed teeth are about .1mm thinner.


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## ultraman6970 (Aug 1, 2010)

It depends on the crankset you have, the new centaur and veloce have stamped chainrings and there is when you might find a problem because the spacing between the chainrings is different from what I read. If you want to find out, let us know 

If your crankset uses regular forged chainrings then probably there is no issues at all. You can use 10S chainrings with 11 w/o any problems.


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## tommyturbo (Jan 24, 2002)

I have many miles on one of my 11s bikes using the 10s rings. I've never had a hint of a problem. I also use a 10s FD with great success on that bike.


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## spectre-73 (Nov 10, 2008)

I have converted both my UT chorus and UT record 10 speed cranks to 11 speed with no problems. The chorus cranks have TA 11 speed chainrings and the record cranks have 11 speed campag chainrings, the campag are probably the better of the two, I picked them up on ebay. I have a pic in the giant section of the record cranks on my giant tcr sl.


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## joeyb1000 (Feb 15, 2011)

Thanks for the info, but my question really related to the change in the part number for the outer chainring starting in 2011.


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## joeyb1000 (Feb 15, 2011)

Here's the answer for reference:

Older aluminum cranks had 10mm chainring bolt holes. Carbon ultra-torque cranks have 8mm bolt holes. There was no change in the crank dimensions in 2010. (The crankset didn't change with 11s, just the chainrings).

Pre-2010 chainrings have 10mm bolt holes. In 2010, that changed to 8mm with a threaded small chainring. 

You can put current 11s chainrings (i.e. SR153/SR139) on pre-2010 ultra-torque cranks, but you need to buy the new bolt set.


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## dvizzoca (Apr 8, 2003)

I have a 10 speed Campy drive train and would like to convert my 10 speed Ergo Chorus Ultra shifter to 11 speed, including swapping out the cassette and chain. 
I see posts that my 10 speed crank will work going over to 11 speed but have a question regarding my Record RD. Will the 11 speed shifters engage the derailleur increments to move the chain accordingly, with fine adjustments on the limit screw's? What kind of tinkering are you referring to?
Thanks for your reply.


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## orange_julius (Jan 24, 2003)

dvizzoca said:


> I have a 10 speed Campy drive train and would like to convert my 10 speed Ergo Chorus Ultra shifter to 11 speed, including swapping out the cassette and chain.
> I see posts that my 10 speed crank will work going over to 11 speed but have a question regarding my Record RD. Will the 11 speed shifters engage the derailleur increments to move the chain accordingly, with fine adjustments on the limit screw's? What kind of tinkering are you referring to?
> Thanks for your reply.


Why don't you start a new thread? Is your post count still below minimum? 

See the following re: 10-sp RD with 11-sp Ultra-Shift shifters.
http://forums.roadbikereview.com/components-wrenching/campy-10-rd-11-speed-drivetrain-160601.html


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