I am wanting to install a 40T Rotor Q-Ring inner chainring on a 2009 Campag Centaur carbon UT chainset.

The Rotor ring is 0.8mm thinner than the original Campag one resulting in the chainring bolts bottoming out without reaching sufficient binding force.

My options appear to be either:

a. filing the chainring bolts down to shorten them.
b. finding spacers that fit into counterbore in the chainring to pack out the chainring bolt.

Any other ideas or recommendations?

I'm interested in this as well; just ordered a set of 50/36 for my Chorus 10 compact and I didn't realize there could be an issue.

I know Branford bike in the US has [url]chainring spacers http://branfordbike.com/product/le-tour ... rs-808.htm" onclick="window.open(this.href);return false;[/url]which might be an option.

I've fitted Q rings to both a 10 speed Record UT chainset and an 11 speed UT Super Record with no issues, are you fitting both rings or just the inner one?

Any shop should be able to get you spacers from Wheels Mfg. in Colorado.

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"Organization is for the simple-minded, the Genius controls the chaos." - Jens

I am running the exact combo you are asking about, with no problems what so ever. Works like a charm! No issues with spacing or anything or chain rubbing the FD at all. Expert bike shop fitting of them though probably helps that.

It sounds like there must be different thickness Centaur and/or Q-Ring chainrings out there.

I am running an inner 40T Q-Ring with original Centaur 53T. I use the same configuration on my 2005 Record carbon crankset and had no installation issues but the chainring bolts were the older larger diameter design.

The original Centaur ring has no counter-bore for the back of the chainring bolt to sit into - it is stamped with only the teeth machined. Conversely the inner Q-Ring has quite a deep counter-bore milled into each bolt hole.

As a work around I found some 12mm stainless steel washers from a hardware store which fitted neatly into the Q-Ring counterbore. Drilling the hole in each washer out to 6mm was all that was required to complete the install. The rings are now on securely without having to take a file to the bolts.

I have found one issue now though as I am getting a BMC SLR team machine. The Centaur FD won't fit on the frame and shift properly anymore. It doesn't sit high enough on the braze on frame mount. So I am having to switch it for either a SRAm or Shimano that has twoholes to adjust the height. Currently got an Ultegra one on but will hopefully switch it to a lighter SRAM Red in the future - don't know about shifting performance though with the SRAM Red and Campag Centaur

I have my 50/36 Q rings mounted on my 2009 Campy Chorus UT cranks and I do find I have one issue. The 36 ring runs very true. The 50 runs true for most of the rotation but moves toward the crankarm (away from the center of the bike) as the DS crankarm moves to a vertical position. Makes me think there's something with the 50 ring thickness where the thin Campy washer which goes between the crankarm and the outer ring is not thick enough. Anyone else have this experience or have any insights?