Campag Centaur 10 speed 34t chainring

[SteveParry]

Possibly 50t too. Ideally to match my Centaur Carbon Compact (Ultratorque) crankset with 5 holes. My inner is v worn and causing a scraping sound when pedalling. I understand the early 11 speed rings may also fit but not certain about this.

 

[mrushton]

Appears to be the hidden bolt version. I may have something in storage.Will check today.

Update. Only 36 I'm afraid but I do have a silver TA 49t in that configuration ie 5 arm hidden bolt 110bcd

 

[SteveParry]

Thanks, I'll hold out for a 34. Didn't know about the hidden bolt thing.

 

[mrushton]

It goes in behind the crank and is offset. Such is the Campag way. Will look again if I have a 34 but have a look at TA as an alternative. BCD is 110 and Nerius is the TA line I think

 

[gbb]

Wasn't sure if I had a very nearly brand new set of Campag MPS 10 sp chainrings of that size dug them out...oh well, theyre 53/39..so different PCD as well id think.
Id have gladly given them FOC.

If theyre of use to anyone, same applies, FOC. Bikes long gone, I dont do roadbikes anymore so theyre just clutter to me.

 

[SteveParry]

Bought a new TA Nerius 9/10 speed 34t 110 BCD ring from e^ay. Also discovered the bolts are not 5mm Hex as thought - they are Torx. Now to find a torque wrench. Any suggestions for a budget model?

 

[berty bassett]

Can look tomorrow if you want ! Used to run same set up and I am not known to throw things away !

 

[SteveParry]

The bolts are supposed to be T27 torx; looks like two of mine might be T30 - perhaps a bodge by previous owner. But I have both T27 and T30 to hand. I just had delivered the giant Park Tool 10mm hex wrench from Amzn - with a 30 day return. Before I use it I wondered if I can remove the chainrings while leaving the crank in place? Would the 34t inner ring slide over the crank spider? If so I could simply return the 10mm hex wrench.

 

[Pblakeney]

The bolts are supposed to be T27 torx; looks like two of mine might be T30 - perhaps a bodge by previous owner. But I have both T27 and T30 to hand. I just had delivered the giant Park Tool 10mm hex wrench from Amzn - with a 30 day return. Before I use it I wondered if I can remove the chainrings while leaving the crank in place? Would the 34t inner ring slide over the crank spider? If so I could simply return the 10mm hex wrench.

You could, but you will probably need it at some point in the future. BB's don't last forever.
That said, my foul weather bike was bought in 2011 with a Chorus crankset and is still smooth and without play. Decisions, decisions...

 

[berty bassett]

The bolts are supposed to be T27 torx; looks like two of mine might be T30 - perhaps a bodge by previous owner. But I have both T27 and T30 to hand. I just had delivered the giant Park Tool 10mm hex wrench from Amzn - with a 30 day return. Before I use it I wondered if I can remove the chainrings while leaving the crank in place? Would the 34t inner ring slide over the crank spider? If so I could simply return the 10mm hex wrench.

You can take rings off without crank , it’s a bit of a faff but you can - it’s teeming down here today , j will go in shed tomorrow morning and post on here

 

[berty bassett]

Been in shed and dug out all the old campag I could find ( silver one may not be suitable ) let me know if any good - I also have a full group set campag 10 speed up the garage with cranks on an old frame but would sell that if interested - not taking off frame if not though 👍
If any of theses are any good your welcome to them

 

[mrushton]

Bought a new TA Nerius 9/10 speed 34t 110 BCD ring from e^ay. Also discovered the bolts are not 5mm Hex as thought - they are Torx. Now to find a torque wrench. Any suggestions for a budget model?

This is one of those Campag tricks that drive me crazy. One chain set had hex another torx. Don't forget that hidden bolt. Chainring only goes on in one way (to match the bolt with the receiver in the crank. Yes to removing the ring over the crank.

 

[SteveParry]

Been in shed and dug out all the old campag I could find ( silver one may not be suitable ) let me know if any good - I also have a full group set campag 10 speed up the garage with cranks on an old frame but would sell that if interested - not taking off frame if not though 👍
If any of theses are any good your welcome to them

Thanks for helping. It's difficult to make out but is the bottom one a 50T? Could you send an image of that one alone? And a close-up of the wear on the teeth? That could be useful. T27 bolts would be useful if you had any but I hope to get away with reusing existing ones.

 

[berty bassett]

def no bolts they are on the group set. will take a photo later

 

[SteveParry]

Just an update. On eBay I spied a new TA Nerius 34t chainring and bought for good price. Without removing the crank I removed both rings. Then fitted the new 34t. This was indeed a faff; esp holding the slotted bolts while torquing up the T27 bolts on other side. It took almost two hours with a second pair of hands at times. If I have to do it again I'll get the Park tools slot holder tool. I torqued all bolts to 8Nm as stated on instructions. On Campag's pdf it says if re-using bolts to use Loctite on threads. I didn't do this as I didn't have any but will keep an eye on them. They were hard enough to remove without any thread compound. (Maybe I should have used some Copper slip paste that I do have? But that would seem to be the opposite of using Loctite?)

Took it for a test ride. Hallelujah - the scraping sound has gone! When I initially received the bike it had an older cassette and chain on. I guess the combination of rings/cassette/chain had been used for a long time and worn together. When I first rode it there was no noise. Then I changed the cassette for a new Miche one and a new chain. It was after doing this I first noticed the scraping sound. So the lesson leaned is don't put a new chain on a very worn chainring. I think the Pearson carbon frame may have been amplifying the noise too.