# Centaur chainrings not standard?



## waterford853

Grrrrrr. I was never crazy about the stamped rings that came on the Centaur and lesser groups. They are less attractive and make more noise than the machined rings on the higher groups. No problem, I'll just order some rings and swap 'em out! Wrong! The stamped rings are 2.7mm vs 3.5mm for the machined rings (measured at the mounting point). Because of the way the rings mount, a thicker ring will not mount without creating a bend in the large chainring. I would rather not have to file the crank arm or the rings to fix this.

I have seen machined rings on UT Centaur groups on this site and the owners say "They came stock". This may only affect the large ring, but has anyone run into this? Know where to get rings that will fit?


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## Topher

Are you talking about the old alloy Centuar, the old Carbon (not Ultra Torque) Centaur, or the newer Ultra Torque Centaur? I believe that there are differences between all three of these. 

I have compact cranks in each of these variations - I don't know if the information I'm providing applies to 135bcd (53/39) cranks. 

The old alloy Centaur stuff (and lower groups) I believe was a "standard" 110 bcd - not compatible with Record machined rings, but I believe, compatible with a lot of aftermarket stuff. Correct me if i'm wrong - I don't know for sure, and haven't tried to replace my rings with non campy stuff, but I do know that the bolt pattern is NOT the same as 110 bcd Record. 

The old Carbon stuff shared the Campy specific 110 bcd, with the single rounded point that bolted into the back of the crank arm. Machined Record Rings ARE compatible with these old centaur carbon cranks. I've replaced a pair myself, with no problem. My understanding is that these older crank arms are identical to the record arms, with the differences being the bottom bracket width they were designed for, and the lower quality rings. You can still find these old record rings on the various UK sites, etc.

I haven't tried to move rings around on the new UT stuff. Looking at it, i'm very surprised that they aren't compatible with the record rings - they appear to share the Proprietary bolt pattern that used to be reserved for Record. 

Hope some of that is helpful...


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## waterford853

I should have been more specific. I am talking about the 135bc. (53/39) on the newer aluminum UT arms.


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## waterford853

At the top of this thread ( http://forums.roadbikereview.com/showthread.php?t=174460 ), you can see that there are some machined campy rings for Centaur... but these do not look like mine ( http://forums.roadbikereview.com/showthread.php?p=1069343&page=3) or the ones shown at campy's website.


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## wankski

i have the machined rings on my centaur alloy UT... the latest ones were downgraded.

Look into TA specialties and Stronglight, campy rings ain't what they used to be anyway. snapped a tooth clean off my (machined) centaur ring. 

I don't know exactly what you mean tho, cos i currently have my veloce UT (which always had the cheap stamped rings) with 05 record rings on it now no problem. did the swap meself.


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## cs1

Machined rings are nice but not worth the extra money. I'm using Daytona 10 sp now. It works just as well as the Chorus it replaced. If you must have machined rings old square taper Record/Chorus cranks are still available on ebay cheap. They're under a $100 and that's cheaper than the cost of rings. Good luck


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## waterford853

I suspect the aftermarket are all matching the 3.5mm spec. I noticed that Campy took the large rings off their site (as replacements) suggesting something is up. I had the old Chorus on my last bike, but I think I will stick with the new UT... they are much stiffer (as determined by FD rub). I think the new rings only are an issue from 2009 on. I have seen several sets of UT Centaur with machined rings, pre 2009.


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## ChunkyMC

I ran into the same problem with my centaur cranks,so I was debating filing down the flat bolt hole area behind the crankarm about 0.8mm or doing the same to a record outer chainring i had planned on using. What did you end up doing?

The new stamped centaur chainrings look like they belong on a department store bike.


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## natedg200202

From my experience, you are better off (financially) selling what you have and finding a 2008 or older Centaur crankset, which will come with the nice machined chainrings. 

http://cgi.ebay.com/CAMPY-CENTAUR-1...Accessories?hash=item4cec02e489#ht_1731wt_940


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## waterford853

eaby... new cranks for about $115 w/delivery now mounted. Much better.


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## edmundtan

For those who have reasons to replace the outer chainrings for the Centaur, Veloce and Mirage UT cranksets (135 and 110BCD), TA Specialites have compatible replacements but they are quite pricey. The 5th arm is slightly offset and machined thinner to fit.

Check out the link here: http://www.chickencycles.co.uk/index.php?cat=32&ord=2

ICYCLES Ebay store also has the machined Centaur 53/39 chainrings going for $50 a pair. Not a bad deal so better grab it before they run out.

http://cgi.ebay.com/CAMPY-CENTAUR-1...Cycling_Parts_Accessories?hash=item35a474660b


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## waterford853

"The Tivano is compatible with Campagnolo Centuar carbon/Veloce/mirage Ultra-Torque cranks. Machined with great precision using CNC. The 5th arm is machined thinner for perfect compatibility, the bolt hole has no recess for bolt head as this bolts straight into back of the crank." 

Note that the ones you show on eBay are NOT the same. They are specific to older Centaur with the machined rings. If you have machined rings, you can use most machined 10spd rings .... if you have stamped rings, then the TA Tivano are the only ones I have seen that can replace the Campy stamped rings now on the lower-end Campy cranks.


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## campagnoloneutron

waterford853 said:



> Grrrrrr. I was never crazy about the stamped rings that came on the Centaur and lesser groups. They are less attractive and make more noise than the machined rings on the higher groups. No problem, I'll just order some rings and swap 'em out! Wrong! The stamped rings are 2.7mm vs 3.5mm for the machined rings (measured at the mounting point). Because of the way the rings mount, a thicker ring will not mount without creating a bend in the large chainring. I would rather not have to file the crank arm or the rings to fix this.
> 
> I have seen machined rings on UT Centaur groups on this site and the owners say "They came stock". This may only affect the large ring, but has anyone run into this? Know where to get rings that will fit?
> --------------------
> I ran into the same problem with my centaur cranks,so I was debating filing down the flat bolt hole area behind the crankarm about 0.8mm or doing the same to a record outer chainring i had planned on using. What did you end up doing?
> The new stamped centaur chainrings look like they belong on a department store bike.


A buddy of mine just encountered the same issue on his 2009 Centaur carbon cranks. He hated the original cheap Centaur chainrings when it arrived and after using the cranks for a couple of weeks. At that point he acquired some new 2009 SR 11SP chaininrings 53-39 to mount and he was real happy until the same mounting issue problem popped up. I am thinking he could just carefully file the 0.8mm off the carbon mounting surface and the newer chainrings would mount Aokay. Its a very small dimension to remove (but obviously significant in this case) and a small flat file and some careful work should solve it.

(and i did beat him up over the facts that if he had either returned the crankset right away or purchased the Chorus 11SP cranks in the first place as he had planned it would have avoided all of this plus he has now not saved anything after purchasing the new chainrings... anyway, moving along...)

Comments/thoughts on doing the above as a solution? Thanks in advance.


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## C-40

*???*

If the rings don't fit the crank, filing on them may not be wise. The important thing to maintain is the correct chainring spacing of 7.7mm tooth to tooth and the chainrings must also run true. You should figure out the consequences of modifing the rings before doing it. A file is poor tool to use for accurately removing that much material.


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## campagnoloneutron

C-40 said:


> If the rings don't fit the crank, filing on them may not be wise. The important thing to maintain is the correct chainring spacing of 7.7mm tooth to tooth and the chainrings must also run true. You should figure out the consequences of modifing the rings before doing it. A file is poor tool to use for accurately removing that much material.


No, no no... not suggesting filing the chainrings themselves! that would be crazy... the filing is needed to remove material on the one mounting surface of the crankarm (the hidden chainring mount point behind the crankarm).


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## waterford853

To c-40's point, keep in mind where that spec may be coming from. Note that the spider arms fit to the outside of the ring and the arm of the crank attaches to the inside of the ring. If you just file the arm, the spacing of the rings may be off causing poor indexing. Sell everything on eBay and start over. The alternative could be a useless crank and a lot of frustration.


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## C-40

*still...*



campagnoloneutron said:


> No, no no... not suggesting filing the chainrings themselves! that would be crazy... the filing is needed to remove material on the one mounting surface of the crankarm (the hidden chainring mount point behind the crankarm).


Still highly inaccurate and you need to be sure of the results before doing it. This advice is from a long time machinist.


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## darkmother

I'm glad I saw this thread. I was just about to pick up a cheap 2006 centaur crank as a ring donor for my new alloy UT cranks (the new rings really are quite nasty looking). I wish Campy had just used a spacer between the ring and the arm if they had to make the rings thinner-they could have kept the arms cross compatible that way. Really frustrating. 

I suppose all component manufacturers are doing the same thing, but that doesn't mean I have to like it.


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## Juanmoretime

I have a set of 2008 Centaur ring with only about 100 miles on them. I pulled them to put a single carbon fiber tt ring for my tt rig. Will let them go cheaply. If interested PM me.


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## ChunkyMC

I'm thinking of filling my crank arm also, but would take it to a machine shop if i could find one that will charge a reasonable price. Anyone know of a good machine shop that could do this in the sacramento/nor cal area?

I've been using campy for over 20 years, have used & interchanged multiple groups, and this is the first time i have felt shimano'd by them.


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## edmundtan

Although the stamped Centaur chainrings do not look too cool, they actually work perfectly. Why not use them until they are worn before replacing them with something else.


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## PlatyPius

Because Purty > Function, don't ya know....


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## ChunkyMC

edmundtan said:


> Although the stamped Centaur chainrings do not look too cool, they actually work perfectly. Why not use them until they are worn before replacing them with something else.



I have been using them for almost a year and will replace when the inner is worn, but I have an unused set of chorus/record rings that I want to replace with when ready.


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## darkmother

ChunkyMC said:


> I'm thinking of filling my crank arm also, but would take it to a machine shop if i could find one that will charge a reasonable price. Anyone know of a good machine shop that could do this in the sacramento/nor cal area?
> 
> I've been using campy for over 20 years, have used & interchanged multiple groups, and this is the first time i have felt shimano'd by them.


Keep us posted on how it works out whatever you decide to do.


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## fah35

*What the difference between the machined rings and the stamped rings?*

I am kind of new to chainrings but what is the difference between the machined rings and the stamped rings? It seems to me from reading the posts that it is only on looks. Wankski said his machined ring centaur had a tooth snapped off. If that is the case wouldnt it better to get the stamped rings?


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## C-40

*coatings..*

SR, Record and Chorus all have a hard anodized coating for improved wear resistance. Athena rings don't and the lower levels are stamped with no coating. Stamped rings are pobably less precise, but obviously they still do the job.


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## ericjacobsen3

Waterford, what you are hearing may be true. Stamped rings may be softer aluminum than machined rings -due to the forming process needs and more cost focus. Machined rings have no forming so they can use hard 7075 or similar aluminum. This improves wear, but if a tooth is hit with a hard load it could be more likely to break than bend.

Still, I would not put much weight on a breaking tooth. Chainrings wear out more than teeth breaking on the road at least. I for one have never worn out or broken a tooth on any Campy or Shimano machined ring on several cranks with 10k+ miles, an not on a stamped Campy ring in 1k miles of use.

As others are pretty much saying, don't sweat it either way unless the aesthetics of stamped rings bother you.


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## Fai Mao

Rather than ruin your crank by taking a file to it because of a chian ring you perceive as ugly why not beautify the chain ring?

I'm serious. Get a buffing pad for an electric drill and some polishing compound. Polish the chain ring until it is mirror like and then spray it with a clear sealant. Basically clear paint that does not require a primer. This is easy to do. If the rings are all ready colored then spray them with oven cleaner to remove the finish. You can buy the clear coat in a hardware store. It is like spray paint. It used to be that a buffing pad came with a small can of polishing compound, it may still for all I know. Just don't polish the actual teeth. Polishing will remove a trivial amount of metal but far less than you'll do with a file and you'll end up with a really pretty crank even if you polish just the out side of the rings.

Just be sure to take the rings off the carbon crank first! It helps to use a screw through the bolt hole to fix the ring to a wooden bench while you polish.

You'll still have stamped rings but they will be really pretty stamped rings. Alternately remove any finish from the rings and paint the a complimentary color to your frame. Just mask off the teeth first.

Holy Cow, don't take a file to a carbon fiber crank. Can you say "De-laminate?" Polish the rings and then tell your snobby friends that you have special "Narrow gauge - Aerodynamic-Chain Rings that decrease the frontal cross section of the crank by 10% and increas the stiffness of the chain rings because the bolts are shorter" or some such scientific sounding BS. Everyone will envy your stamped rings.


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## ironmandreamer

*OK, it looks like I have followed others into this chainring problem. I purchased a Campagnolo Centaur Carbon Groupset when the Aussie Dollar hit 50p. Who would have thought it would ever reach 60! I didn't buy Chorus because I didn't want to risk getting hit for import duty / GST for a purchase over $1000; the Centaur sneeked in under this mark.

When I got the group I wasn't happy with the cheap black chainrings so I sold them on eBay and for $60 upgraded to 2006 Record rings. I made the change purley for asthetic reasons, the bikes a Merckx 1XM and I wanted it to look the goods....

Now what approach should I take to fixing my problem? I've put the bike together with the help of a friend who has all the gear and being an Engineer, all the know how; until we struck this problem.... I'm sure with instruction he'll be able to make the necessary modification.

When the chainrings are turned we thought there was definately a highspot for want of a better term and that one of the crankarms was definately out 1 or 2mm, but definately out of true. So now I want to clarify, the problem is with the 5th hidden bolt, the other four arms are fine.

I need to hear from anyone/everyone who has previously experienced this problem? And if you stuffed it up, tell me what to look for so I don't do it too. Again, I've sold the original chainrings so don't have the option of putting them back on.

I'm after some guidance.*

Regards
Clayton


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## campagnoloneutron

ironmandreamer said:


> *OK, it looks like I have followed others into this chainring problem. I purchased a Campagnolo Centaur Carbon Groupset when the Aussie Dollar hit 50p. Who would have thought it would ever reach 60! I didn't buy Chorus because I didn't want to risk getting hit for import duty / GST for a purchase over $1000; the Centaur sneeked in under this mark.
> 
> When I got the group I wasn't happy with the cheap black chainrings so I sold them on eBay and for $60 upgraded to 2006 Record rings. I made the change purley for asthetic reasons, the bikes a Merckx 1XM and I wanted it to look the goods....
> 
> Now what approach should I take to fixing my problem? I've put the bike together with the help of a friend who has all the gear and being an Engineer, all the know how; until we struck this problem.... I'm sure with instruction he'll be able to make the necessary modification.
> 
> When the chainrings are turned we thought there was definately a highspot for want of a better term and that one of the crankarms was definately out 1 or 2mm, but definately out of true. So now I want to clarify, the problem is with the 5th hidden bolt, the other four arms are fine.
> 
> I need to hear from anyone/everyone who has previously experienced this problem? And if you stuffed it up, tell me what to look for so I don't do it too. Again, I've sold the original chainrings so don't have the option of putting them back on.
> 
> I'm after some guidance.*
> 
> Regards
> Clayton


I know exactly the problem you have encountered.
See my previous post on this thread (see entries and the following posts) My buddy was in the same situation. I looked at solutions with him from all angles and the conclusion was that the best course is not to mess around with modifying the cranks... He sold the new chainrings and also sold the cranks. Then he bought what he should have in the first place, the complete Chorus crankset that comes with the nice chainrings and the bottom line was he was not out a lot of $ and it was right.


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## ChunkyMC

*hi-tech fix*

When my big chainring wears out or I get motivated enough I will bust out the calipers,measure the thickness of the crank, take a file & remove aluminum from flat section, measure the diffrenece (1-2mm). If I file to much I can put in a thin spacer. It dosent need to pretty just flat & even. hi

If I didnt have extra record/chours rings laying around I probabaly would not worry about it, and I'm not throwing more $$ to take it to a machine shop.


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## ironmandreamer

At this stage it looks like my Engineer mate is going to have a toolmaker machine 0.8mm from the crankarm so that standard Chorus / Record 10-speed chainrings will fit. We considered machining the chainrings but this is a better fix as replacement chainrings will be able to be bolted straight on. I'm fortunate that I'm having this work done FOC but don't know when it will be ready to go.... My mate rides the 10-speed Chorus group so he has cranks to measure, and remeasure to get it right. If this option wasn't available I'd be buying the TA rings.


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## headloss

Sorry to reawaken this thread from its slumber... but it's the most recent on-topic thread that I could find.

I have a 2010 model of the Centaur UT (alloy) that I picked up on ebay. I took off the rings and they both measure 3.0mm (by caliper) at the mounting points. I'm skeptical that the OP's measurements were correct and I'm looking for verification one way or the other. Also, FWIW the distance between the rings fell somewhere between 3.5mm and 3.6mm (I need a different caliper for a more exact measurement). 

I found one shop on ebay that verified the 3.0mm thickness. This shop claimed that the 9speed rings were the same thickness. Branford seems to support this statement, although they don't provide the measurements. *So, my question is, are the later veloce-based centaur ten speed rings interchangeable with older 9speed Chorus rings?*

I'm OK with the _ugly_ 2009+ alloy-centaur chainrings that look like a_ pie pan_, but I'm trying to stock up on NOS parts while they are available and trying to figure out my options. Also, FWIW, since it wasn't mentioned elsewhere in this thread... per the campy tech specs, the better centaur UT cranks were the 2007-2008 alloy version. The 2008 carbon version had the veloce rings.

Ironically, the same year that campy down-graded the centaur rings, they up-graded the FD... strange company.

Anywho, thanks for any light you can shed on this. Info on chainring thickness seems to be lacking on the net. Was there a change when the Chorus (and up) rings migrated to UT or are all 2004-2008 Chorus/Record 10speed rings the same dimensions? Branford doesn't seem up-to-date with info regarding the UT cranks/rings. They do however suggest that the 9speed Chorus ring is identical to the 10speed Veloce ring in regards to fit. It is also stated that the 10speed rings are the same thickness but machined down at the mounting points for a narrower gap between rings while the Veloce-style 10speed removed material in the crankarm itself to maintain the same gap...

If that is the case, then the UT 10speed Chorus(and up) rings should be thinner, not thicker, at the mounting point than the respective Veloce rings. This thread seems to be suggesting the opposite. What am I missing?


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## DrSmile

I had a compact UT Centaur crank with the stamped rings. I used replacement Stronglight Zicral 7075 110mm Camp 9/10 Chainrings from Ribble:

Stronglight Zicral 7075 110mm Camp 9/10 Chainring, CHAINRINGS

They also sell 135mm rings. Note I had to use shims to get the spacing correct because the rings are made for Chorus/Record. So no the rings are not direct replacement or transferable from Chorus to Centaur without shims. I think I needed to shim the four arms that don't attach on the crank arm. I would imagine you'd have to do the same for Chorus rings.

Eventually I manned up and bought a Chorus crankset...


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## headloss

DrSmile said:


> Eventually I manned up and bought a Chorus crankset...


I may do that, but... it would be the square-taper variety as I want alloy.


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## DrSmile

headloss said:


> I may do that, but... it would be the square-taper variety as I want alloy.


All the Chorus chainrings are alloy.


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## headloss

DrSmile said:


> All the Chorus chainrings are alloy.


I'd hope so! 

Unfortunately, the selection of alloy crank-arms with ultra-torque is limited. 
I think with rings, it might just come down to ordering parts and seeing what I can make work together (files, shims, etc.). If it doesn't fit, I'll just have to buy more parts (and more bikes... see how that works *until the sig. other hides the credit card).


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## DrSmile

headloss said:


> I'd hope so!
> 
> Unfortunately, the selection of alloy crank-arms with ultra-torque is limited.
> I think with rings, it might just come down to ordering parts and seeing what I can make work together (files, shims, etc.). If it doesn't fit, I'll just have to buy more parts (and more bikes... see how that works *until the sig. other hides the credit card).


Sorry, I didn't realize you meant the cranks not the rings. Having done the fiddling, I can tell you it's not really worth the headache. Even if you get the spacing correct so the chain is picked up and dropped properly, the rings may now be placed too far inboard or outboard relative to the crank, throwing off the chainline enough to cause chain rub on the large ring. Even though I got it to work perfectly on a square-taper Centaur crank I still use, it involved a lot of re-visiting of the issue until it was perfect.


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## headloss

No doubt... and I likely wouldn't bother unless I was unable to find matching rings down the road. My primary concern is just to determine what does/doesn't fit while there is still an abundance of NOS 10 speed parts floating around (and to a lesser extent, the 9 speed stuff). I'm new to campy and trying to learn the minute differences in components/parts over the last decade or so.

If I do have to fabricate, I'm competent and have had machinist training; but, I'd rather buy parts that fit in the first place. Are the only Campagnolo-made rings that fit 2009+ Centaur/Veloce cranks the original equipment... or are there other options? Are the Veloce rings from the square taper days a different size than UT (referring to the 135s, I know the compacts had the offset on one arm)?

Branford suggests that the 9speed Centaur/Daytona/Athena/Chorus/etc. rings are the same size as the 10speed Veloce while the the other 10speed rings are machined thinner at the mounting point in order to reduce the spacing between rings. But, the OP in this thread suggests that the machined-rings are thicker. It sounds like there must have been some change in the thickness of the Veloce rings when they moved to UT?


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## CheapSkate

headloss said:


> ...Are the Veloce rings from the square taper days a different size than UT (referring to the 135s, I know the compacts had the offset on one arm)?...It sounds like there must have been some change in the thickness of the Veloce rings when they moved to UT?


I have 5 arm 10s Centaur square taper spiders, 59/39. I swapped the original (polished metal, EPS, 8 pin) chainrings for 2013 model (MPS, 8 pin, 2 x heavily cut down downshift pins, black paint) 10s Veloce rings taken off Power Torque spiders. 

They were a "perfect" fit, I did not measure the thickness with calipers but they fit perfectly, they mount flush with the spiders both for the inner and outer ring. IIRC I didn't even need to re-trim the FD (I didn't take the crank arm off)

The only thing that was not perfect is the big ring 5th bolt hole does not have a recess for the bolt (because the 2013 Veloce has 4 arms, the 5th bolt goes through from the small ring into the arm) so I had to machine a recess.

I've done a couple of thousand miles on these MPS chainrings and I like them a lot. They are quiet & they definitely shift more smoothly - I can shift both ways under full power (not that I do that if I can avoid it)

I can't comment on longevity vs EPS rings, but I am skeptical of this forged/machined/stamped argument, it's just ally, won't it wear the same? Also I think the MPS rings _are_ heavily machined, I suspect there is just a final polishing process that's missed out? Maybe I'm missing something


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## bikerjulio

> Are the Veloce rings from the square taper days a different size than UT (referring to the 135s, I know the compacts had the offset on one arm)?


I have used Centaur square taper compact cranksets, and recently sold a few in my collection. They were one of the few (only?) Campy cranksets to use an utterly conventional (110 BCD), bolt pattern. Any 110 BCD chainring will fit.


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## strathconaman

waterford853 said:


> ...The stamped rings are 2.7mm vs 3.5mm for the machined rings (measured at the mounting point). Because of the way the rings mount, a thicker ring will not mount without creating a bend in the large chainring....


I am a little confused. I replaced a set of worn stamped rings on a centaur ultra-torque crank with rings taken from a nos ultra-torque crank purchased of Fleabay (for less $ than I could buy the rings). There was no bending required. Is it possible that the new stamped rings are the same width as the eleventy speed rings? 

I bet C40 knows the answer off the top of his head.


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## headloss

@strathconaman,

Centaur 2007 and 2008 UT (53/39) were set up with a Centaur-specific rings which had the same dimensions as the Chorus rings for UT (more or less). In 2009, the Centaur model started to use the Veloce rings which are a different thickness.

What's confusing me is how the square-taper vs UT variations in ring thickness plays into it. I hope that helped.


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