Campy triple BB question

[zmudshark]

I think I know the answer, but just to be sure...Does a Centaur square taper triple BB take a 115.5 BB on a 28.6 OD seat tube frame with braze on FD? Would a Chorus triple take a 111 on the same frame?

Thanks.

[TMB]

I think I know the answer, but just to be sure...Does a Centaur square taper triple BB take a 115.5 BB on a 28.6 OD seat tube frame with braze on FD? Would a Chorus triple take a 111 on the same frame?

Thanks.

yes
yes

[bikingshearer]

They should both take a 111 mm spindle. However, the Centaur crank (Veloce, too) needs a symetrical spindle and the Chorus crank (Record also) needs an asymetrical one (+3mm, I think). And I can never keep sgtraight where the Comp Triple and Racing-T cranks fall in this mess, although they are all 111 mm spindles for a 28.6 seat tube.

[Ralph]

They should both take a 111 mm spindle. However, the Centaur crank (Veloce, too) needs a symetrical spindle and the Chorus crank (Record also) needs an asymetrical one (+3mm, I think). And I can never keep sgtraight where the Comp Triple and Racing-T cranks fall in this mess, although they are all 111 mm spindles for a 28.6 seat tube.

For the 5 arm Centaur, veloce, comp triple, etc cranks, and 28.4 MM seat tube, use a Centaur 111 MM BB. it's symetrical BTW. It's same BB as you use with a Centaur or similar double. I also use the Centaur Triple, 32 MM seat tube, and 111. Some use the 115.5 with 32, and for sure the larger seat tube.

The Record and Chorus Triple (with hidden arm) use a totally different BB......111 MM asymetrical. I know.....I've got all of them.

[zmudshark]

Peter@Vecchios, do you have the definitive answer?

From what I can gather, a Centaur square taper triples and a Chorus square taper triples should use different BB.

The last model of the Centaur square taper comes in 111 and 115.5. The cranks will be used on a Columbus SL/SLX frame with a braze on FD, OD of 28.6.

I was previously running a 32 mm clamp on FD on a seat tube of 29.0 with a shim and a 115.5 BB with a centaur triple. No issues. I would like to switch everything, other than the FD, to a braze on 28.6 seat tube bike.

Thanks

[buldogge]

John...On a 28.6 tube you should only need the 111mm...The 115 is for larger diameter seat tubes.

I am running a 111mm with a Centaur Century Triple on an SP/SPX ST on my Spectrum.

-Mark in St. Louis

[oliver1850]

You should use a 111 spindle with a 28.6 seat tube, unless the braze on tab is some strange long length.

The 115.5 will probably work on the 28.6 ST frame. You will just have a wider Q factor than necessary, and the chain line will usually be better with a 111 spindle.

I can send you a 111 to try if you'd like.

[oldpotatoe]

I think I know the answer, but just to be sure...Does a Centaur square taper triple BB take a 115.5 BB on a 28.6 OD seat tube frame with braze on FD? Would a Chorus triple take a 111 on the same frame?

Thanks.

Centaur111 for a 28.6..115 for a 31.8 or 34.9...bit since all the extra MMs aren't on the RH side, a 115 will work on 28.6 also. It's for sufficient inward FD travel, not chainline.

Chorus and Record triples are not symmetric, 111mm only. Centaur 111mm is symmetric.

[oldpotatoe]

Peter@Vecchios, do you have the definitive answer?

From what I can gather, a Centaur square taper triples and a Chorus square taper triples should use different BB.

The last model of the Centaur square taper comes in 111 and 115.5. The cranks will be used on a Columbus SL/SLX frame with a braze on FD, OD of 28.6.

I was previously running a 32 mm clamp on FD on a seat tube of 29.0 with a shim and a 115.5 BB with a centaur triple. No issues. I would like to switch everything, other than the FD, to a braze on 28.6 seat tube bike.

Thanks

They do, see post.

Again, it's for inward travel...you can use a 115 on a 28.6mm seat tubbed bicycle.

[sjpitts]

It's for sufficient inward FD travel, not chainline.

This is the first I have heard of this. What is it about the centaur triple that requires the extra spindle length for a larger diameter seat tube?

You don't need it for the chorus/record doubles--- right? All those are 102mm no matter what?

And you don't need it for chorus/record triple-- right? All those are asymmetric 111mm no matter what?

And it is not true for Shimano as far as I know.

So what is it about the centaur triple that makes the spindle length need to be changed for a larger seat tube?

[oldpotatoe]

This is the first I have heard of this. What is it about the centaur triple that requires the extra spindle length for a larger diameter seat tube?

You don't need it for the chorus/record doubles--- right? All those are 102mm no matter what?

And you don't need it for chorus/record triple-- right? All those are asymmetric 111mm no matter what?

So what is it about the centaur triple that makes the spindle length need to be changed for a larger seat tube?

Because with a fatter seat tube, and symmetric BB, the FD is farther out and it can be hard to get the chain onto the small ring w/o the FD hitting the seattube. Other doubles and Record/Chorus triples, the chainrings are designed and made on the crank so you HAVE sufficient FD inward travel, that an a not symmetric BB for the aforementioned triples.

Happens a lot with really fat, flared seatubes, Serotta Legend comes to mind.

I have modified more than a few with a big socket and bigger hammer...so the FD goes in farther.

[TMB]

Because with a fatter seat tube, and symmetric BB, the FD is farther out and it can be hard to get the chain onto the small ring w/o the FD hitting the seattube. Other doubles and Record/Chorus triples, the chainrings are designed and made on the crank so you HAVE sufficient FD inward travel, that an a not symmetric BB for the aforementioned triples.

Happens a lot with really fat, flared seatubes, Serotta Legend comes to mind.

I have modified more than a few with a big socket and bigger hammer...so the FD goes in farther.

The significantly greater "dish" on the Centaur spiders must be a large factor in the travel problem.