Jantaras

Hello,

I have these NOS cranksets for my future projects: Athena (1988-1992), 9 speed Record and Centaur (I would guess 10 speed?). I would like to buy new bottom brackets for them.
AFAIK, Athena and Centaur needs 111 mm and Record 102mm axle. Will these new Campagnolo Centaur and Chorus bb's be compatible? Did Campagnolo change their tapers from 1988-1992 Athenas to 10 speed Centaurs?

13ollocks

There are only two significant taper standards - ISO and JIS. Campagnolo has only ever used ISO as far as I know. Since '95 I've been swapping Campag cranksets and BBs without a thought for taper compatability - never had a problem.

Jantaras

Thanks, 13ollocks. I vaguely remember that Campagnolo changed the taper angle sometimes, but for their much older cranks, like 50 years ago.

SurferRosa

Campagnolo changed from proprietary to ISO around '94. JIS (not ISO) has been said to fit better on vintage Campy cranks. More info here:

https://www.bikeforums.net/classic-v...o-jis-iso.html

Kontact

That's baloney. In 1994 the C-Record era taper was formalized as ISO. When I needed an Italian BB for my 89 Athena crank, I bought the same length late 90s Campy cartridge (115mm?), and it mounted up perfectly for depth and chainline.

Mavic is often mislabeled as JIS, but I checked with their tech guy and their 80s spindles were also an A match to Campy and ISO. Nuovo Record spindles were an A- fit. JIS wasn't even close, and you'll find that JIS is actually a shallower taper angle.

Keep in mind that the Athena crank became the Chorus crank in 1991, but all 5 of the C-Record style groups were the same spindle.


I think this JIS nonsense comes from Phil Wood.

JohnDThompson 

Campagnolo made a lot of tweaks to their bottom brackets, but the taper angle has always been 2°, while the offset and taper dimensions have changed. Both ISO and JIS tapers are also 2°, but the dimensions at the start and end of the taper are different such that arms designed for one taper don't generally mount properly on spindles designed for the other taper. It's always best to have the parts in hand and test-fit when mixing models and eras.

Kontact

Campy/Mavic/Stronglight/Sugino is actually an obviously different taper angle than JIS. If you mate the spindle flats together you'll see the first group are all the same and JIS is shallower.

We all repeat 2 degrees all the time, but no one checks. I checked.

SurferRosa

"Early Campag cotterless axles had their own taper, JIS is the slightly better match to the early Campag axles – thanks to Michael Alford for this information. At some date, I have heard 1993/4, they converted to the ISO standard, this results in a slight change in the length of the tapers."

Much more info here:

https://www.classiclightweights.co.u...bracket-axles/

Kontact

You can mount cranks and check. I did. You can call the dealer tech line of Campy and Mavic. I did. C-Record matches ISO in dimensions and taper angle.

SurferRosa

I have the troll on ignore.

Dave Mayer

I have about 20 pounds of Campy BB's from the 70s to the very last generation Centaur/Record/Chorus units. With a digital caliper I measured the width of the Centaur (several) tapers vs. a few C-Record era (1980s shield logo) spindles 3mm from the ends. The same for both groups within measurement tolerances.

Kontact

Of course you do. Ignorance is best maintained that way.

Everyone else can consider where, in 1994, this "new" standard called ISO came from.

SurferRosa

"The difference between ISO and JIS lies in the length of the tapers. ISO is longer, resulting in a smaller ‘square’ at the end..."

https://www.classiclightweights.co.u...bracket-axles/

Kontact

This goes on to claim the same taper angle, and they are observably different.

Dave Mayer

I did not measure any JIS spindles. Read my posting closely: I measured 80's Campagnolo spindles against 2000-era Campagnolo spindles and they are the same at the ends.

Further, the length of the taper is irrelevant. If the taper is long enough to get full engagement between the spindle and the crankarm, then having a longer taper doesn't do anything.

SurferRosa

Not if you've ever run into the bolt bottoming out on the spindle.

Please take a look through this thread, including posts 20 (tech from the Sutherlands guide) and 21:

https://www.bikeforums.net/classic-v...o-jis-iso.html

Kontact

Dave is correct. Two spindles with the same taper angle and end width will have the same depth in the crank arm.

Dave Mayer

Here is your answer.. You'll want to ignore the irrelevant meandering contained in most of the previous posts, which includes pointless discussions of JIS, taper angle and taper length. And philosophical wranglings as to whether Sheldon Brown knew his stuff.

So to recap, I closely measured two sets of Campagnolo spindles, one set from the C-Record era (80s) and another set from the 2000s. At the ends, they are the same. So when properly installed, the cranksets should sit in the same relative positions.

The length of the tapers is irrelevant, as long as your parts are all Campy, and haven't be seriously mangled by over torquing. I've only seen a small number of square-taper crankarms in which they bottomed-out at the ends of the tapers. First category was where someone was using completely mismatched spindles and arms. Such as using a late Shimano arm with an Ofmega/Avocet spindle. Second case is where someone had torqued an alu crankarm at 10,000 foot pounds, and so deformed the square taper that it bottomed out on any spindle.

But since your are installing Campy on Campy (carefully) then this isn't an issue.

SurferRosa

My latest venture into mixing vintage Campy and JIS/ISO came with this '91 Bottecchia, where I'm using a mid-'80s Triomphe crank and Shimano tricolor symmetrical bb. It's pretty near perfect. Triomphe calls for a 116mm asymmetrical spindle, and the Shimano is 115 symmetrical.



[MENTION=444751]Jantaras[/MENTION] will be interested in this... A few years ago, I used a new 111mm ISO bb with an '80s Chorus crank in a Japanese frame (below). It works just fine, no shifting issues nor noise. But the chainline is sitting a couple mm further away than that "perfect" mark. And the nds arm is a good 5mm from the cup.



One possibly important issue I've read from other form members is the new ISO spindles are machined better than some of the JIS stuff out there.

Jantaras

Ok, thanks all for your inputs! I think, when I get my next project, I'll buy one of them Campagnolo new BB's, either 111mm for Athena and Centaur or 102 mm for Record and try them. And report here

Kontact

The reason this often works is because of the difference in taper angle. The slimmer taper on JIS let's get in further and deform the ISO profile in the crank, like a splitting maul.

The net effect is either that the crank has permanently deformed to the JIS shape overall, or that only the area closest to the tip of the spindle is in close contact with the spindle, while the area further in is unsupported. Either way, it does work, but it isn't good for the crank and would probably not be a good idea to go back to the correct spindle.


I first started looking at these issues when I was looking to move my Mavic starfish crank from a BSA to Italian frame. Years earlier I had been advised to use a JIS BB - which was a common perception at the time. When I was looking into it I was at a shop that happened to have a Mavic cartridge BB and a lot of Campy and Shimano BBs from different eras. When I posted my measurements I was told I was wrong (sound familiar), but told who to talk to at Mavic. Which is where I got acknowledgement that much of what we have all been told by various guides was wrong - ISO is Campy, and so is Mavic.

Given everything, I decided to stick with the JIS that had already been in the Mavic, and I decided to put the '80s Athena group on the Italian frame - prompting the call the Campy USA and Mirage ISO BB as a perfect replacement for the '89 Campy spindle.


I think the main reason this is hard for people to swallow is that no one ever questions the 2 degree thing.

KerryIrons

If they did make a change it was WAY before 50 years ago. They basically set the ISO standard from their designs in use from at least the early '60 and probably from their first "cotterless" cranks.

SJX426 

[MENTION=493684]SurferRosa[/MENTION] - beautiful Bott!

JohnDThompson 

With the caveat that the arm must seat properly on the spindle.

Kontact

Dave's point was in response to the claim about overpenetration, and he was right - you won't get to C if the ends are the same dimension. A is a different issue, and is yet another reason to figure out and use the correct ISO style spindle where appropriate.