[tobyinsydney]

I've just taken delivery of a 2012 S-Works 29er with XTR and I want to swap out the crappy chainrings for XX (26/39).

My question is, anyone running more than the Shimano FD recommended 12 tooth gap on their Epic?

I'm sure it will be fine but wanting any advice...

 

[Asta]

Will the XX rings fit ok? XTR can sometimes be hard to find replacements.

I'm running a 22/36 double on my crankset no problems.

 

[Jacobus]

I am running a XTR Double Derailuer and a Sworks Crank with 42/28 XX spider. Shifts perfect, no rub in any gear selection.

 

[CerveloMikey]

If you have the Specialized carbon crank, then you have XX chain rings. My '11 SW has the Truvativ/XX rings (24/38) with custom spider. It chain sucks all the time under load. If you have a XTR crank stick with it!

 

[tobyinsydney]

I have the Specialized carbon crank with the Truvativ rings, 24/38... they look more like X9 than XX level.

Sram make a specific XX spider 26/39. Going to head to my dealer to get the rings off later this week as I obviously don't have the right tool in my collection!

 

[skiwi]

If you have the Specialized carbon crank, then you have XX chain rings. My '11 SW has the Truvativ/XX rings (24/38) with custom spider. It chain sucks all the time under load. If you have a XTR crank stick with it!

Those rings are not XX, they are not even X-Glide. The XX rings require a specific spider due to the BCD. I agree that the original rings (the same as on the 2012 regrettably), are rubbish. I have gone with XX (26/39) with the XX spider, and the shifting is fantastic.

 

[CerveloMikey]

You don't need to change the spider to change the rings. Are you just looking for the bling of the XX spider? Looks like somewhere along the line Specialized and SRAM stopped putting XX on them.

Check this thread...

I can't post a link! Look below.

 

[CerveloMikey]

I have 10 posts now...

Here is the link

http://forums.mtbr.com/sram/where-buy-sram-xx-chainrings-574322.html

There are some photos and info there. Same basic stuff that we have.

 

[tobyinsydney]

You don't need to change the spider to change the rings. Are you just looking for the bling of the XX spider? Looks like somewhere along the line Specialized and SRAM stopped putting XX on them.

Check this thread...

I can't post a link! Look below.

I already have the new rings and spider in my possession. I could just pull the rings off the old spider... but yeah maybe the bling of the slightly nicer spider will look better.

I don't have the tool to remove the 'lock ring' that holds them to the crank arms. Its a Specialized specific tool...

As well as the bling I am after better shifting and different ratios

 

[skiwi]

I already have the new rings and spider in my possession. I could just pull the rings off the old spider... but yeah maybe the bling of the slightly nicer spider will look better.

I don't have the tool to remove the 'lock ring' that holds them to the crank arms. Its a Specialized specific tool...

As well as the bling I am after better shifting and different ratios

Can you measure the BCD of the existing big ring and post here? I can be absolutely categorical that the 2011 spider doesn't work with XX rings due to the use of a different BCD. From what I can see from the photos, the 2012 is the same.

 

[GTR2ebike]

You need to change the spider/ring assembly. As skiwi said the bcd is different.

 

[jathanas]

Can you measure the BCD of the existing big ring and post here? I can be absolutely categorical that the 2011 spider doesn't work with XX rings due to the use of a different BCD. From what I can see from the photos, the 2012 is the same.

+1

The 2011 spider is a conventional 104/64 BCD, not the XX specific 120/80?. Moving to XX rings requires installing the XX spider.

Totally worth it, IMHO.

 

[tobyinsydney]

Oh the confusion amongst readers...

I have a set of Specialized XX specific rings. 120 BCD, same as what comes with the bike... (EDIT or maybe not, I haven't measured them)

I could pull the rings off this and stick them on the existing spider but instead I will put the whole shebang on.

 

[tobyinsydney]

+1

The 2011 spider is a conventional 104/64 BCD, not the XX specific 120/80?. Moving to XX rings requires installing the XX spider.

Totally worth it, IMHO.

hmmm actually I haven't measured it, as I never thought about putting the new rings on the old spider. Maybe it is 104/64 after-all.

Regardless... I'm not keeping it!

 

[skiwi]

Oh the confusion amongst readers...

I have a set of Specialized XX specific rings. 120 BCD, same as what comes with the bike... (EDIT or maybe not, I haven't measured them)

I could pull the rings off this and stick them on the existing spider but instead I will put the whole shebang on.

OK, so that means that Spec has upgraded the spider and rings for 2012, although the pictures look identical to the 2011. Can you post a pic of the OEM spider & rings please?

 

[GTR2ebike]

This thread makes me laugh. Stock s-works epic 29er chainrings are still 24/38 rings (64/104 bcd).

 

[tobyinsydney]

Sorry no tape measure...

 

[skiwi]

Sorry no tape measure...

Those are NOT 120BCD rings - they are the same rings as the 2011 i.e. 104BCD. As I stated before you need to replace both the rings and the spider with the XX items.

 

[tobyinsydney]

Those are NOT 120BCD rings - they are the same rings as the 2011 i.e. 104BCD. As I stated before you need to replace both the rings and the spider with the XX items.

Exactly... this is what always planned to do!

 

[Burning Matches]

Here is another option: You can get the new 2x10 X0 chainrings and spider, which are 64/104 BCD and X-Glide. The chainrings will fit the S-Works crank and spider. True XX rings will not fit, as others have said - they have a 80/120 BCD. I thought of upgrading my entire crankset to XX but did not want to move up to a 26/39 chainring combo.

It's an easy swap. I recently did this and the shifting is fantastic and instanteous. I never had any serious problems with the stock chainrings (X7 or whatever they are) on my S-Works crankset but the X-Glide makes a significant improvement.

I replaced mine with 22/36 rings. With the 24/38 I was never in the top gear, even going full speed on pavement, so it was basically a useless gear combo. With the 22/36 I get extra power in the bottom end and now will occassionally use the top gear. I am an endurance racer and after 10 hours I appreciate the easier granny gear.

I never understood how Specialized could legally call the stock chainrings "XX" -- that is false advertising IMO. They are not even close. The bike SHOULD come with the new X0 rings for the best shifting possible.