Campagnolo chainring question

[Nismo4x4]

Hi everyone

I scoured the internet for an answer but wanted to confirm with the experts.

I have a 2011 Athena carbon compact crank (Power Torque) with 50/34 chainrings.
Will I be able to buy any modern 52t and 36t chainrings that are Campy 110bcd and will they fit? I don't really have the cash to buy a whole new standard crank with rings so this seemed like my best option.

These are the rings that I was interested in:
Outer http://www.ebay.com/itm/Campagnolo-FC-AT652-Compact-Chainring-52T-Carbon-Outer-Ring-/161328677387?pt=US_Chainrings_BMX_Sprockets&hash=item258ff0420b&autorefresh=true

Inner http://www.ebay.com/itm/Campagnolo-11-speed-36t-Chainring-for-2011-and-later-Super-Record-Record-and-/400759991031?pt=US_Chainrings_BMX_Sprockets&hash=item5d4f282af7

They state that they're for Chorus and up which is where my concern lies.

Thanks a lot for the help!

[fdegrove]

Hi,

Neither would work it seems.

Ciao,

[bikerjulio]

I did a little bit of digging.

This whole area is one of much confusion because of the many types of Campy rings and the changes over the years.

The newer Chorus rings use a threaded inner ring, specific chainring bolts, and I believe the spider's arms match. There could be other differences - I don't know.

Your crank uses the more conventional screws and nuts instead. The Campy site has links to the spares catlogs like this http://www.campagnolo.com/media/files/035_146_Catalogue_spare_parts_tools_Campagnolo_2014_part_A.pdf

[graeme_f_k]

There should be no confusion on 11s rings, really.

Pre 2012, 11s crank sets and rings were / are all interchangeable within spider type (compact or standard).
2012 - 2014 11s chain rings and 11s crank sets were / are are all interchangeable within spider type.

9s / 10s is, granted, more complicated but as all 11s rings are basically the same in terms of thickness at the attachment point (which is where it *can* get confusing and there were / are differences in 10s), then so long as the fixing method is the same (and as bikerjulio says, that changed in 2012), then within the boundaries above, in terms of fit to the spider, it's simple.

Like most other OE manufacturers, Campagnolo do specifically ramp and pin their rings so that they shift predictably and well in certain combinations - so you ideally want, say, FC-SR250 & FC-SR134 as a pair, to get the best possible 50/34 shift (i.e. the most up to date versions of each, ramped and pinned appropriately).

In the case of 52/36, one of the changes made to make 52/36 shift really well was to increase the rigidity of the outer ring (done at the same time as to improve this property for EPS) and that is what bought about the change in the chairing bolt arrangement - extra material is left in the attachment points at the spider and there is one less mating surface to consider, in addition to changes in the distribution and amount of material in the outer ring. These are incremental points but it is lots of tiny changes like these that add up to better shifting.

So, a retro-fit using Campag rings to a pre 2012 spider can't be done using stock parts. I can see a workaround, but you'd need access to a very competent machine shop ... and even then, I'd want to physically try it myself and it would definitely fall outside of Campagnolo's recommendations.

HTH
Graeme
Velotech Cycling Ltd
Campagnolo main UK SC

[bikerjulio]

Graeme, I don't understand this statement

Pre 2012, 11s crank sets and rings were / are all interchangeable within spider type (compact or standard).

since this is clearly not the case just from a look at the parts catalog. Chorus uses bolts with a threaded inner ring, while Athena uses conventional bolts and nuts. Plus the p/n's are different (which is the only way us mortals have of figuring out interchangeability). How could they be interchangeable?

for the rest of you, here's the reference

http://www.campagnolo.com/media/files/035_155_Catalogue_spare_parts_tools_Campagnolo_2011_part_A.pdf

[Nismo4x4]

Chorus uses bolts with a threaded inner ring, while Athena uses conventional bolts and nuts.

When you say conventional, does that mean any standard 110 bcd rings will work on the old (Pre 2012) cranks or only specific Campy rings?

[bikerjulio]

It's the bolts that are conventional. Campy CT rings have a specific (non-110 BCD) spacing on the hidden bolt hole.

You need Campy-specific rings. They are available I believe.