Hey all,
I'm thinking about running a 1/8 DA chain wheel (49) and 1/8 Campy rear cog (15) on my bike.

Given the teeth are slightly different (DA has sharper teeth and Campy squarer, I'm wondering if I should have them match Both DA or both Campy.

Any advice?
Ash

I wouldn't notice a difference between any of those set-ups. I also wouldn't spend more money to have matching drivetrain parts. YMMV.

What hub are you running? Did Campy make any BSA threaded cogs? Give us some more specifics and don't buy something that potentially doesn't even fit your hub...

Although English and Italian hub threading is not identical, it is sufficiently close to interchange cogs and freewheels. The pitch is the same (24 TPI) and the difference in diameter is only 0.2mm. A Campy cog will be a slightly loose fit on an English threaded hub.

This is irrelevent, since the chainring and cog do not mesh directly, and the chain just needs to also be 1/8".

Sheldon: "English and Italian are all semi-interchangeable, but you shouldn't go back and forth between different types of freewheels on the same hub repeatedly."

Apparently Surly even issues the same warning: "It is important to not switch back and forth between cogs and/or hubs with different threads." (https://surlybikes.com/uploads/downlo...og_5.16.05.pdf)

I personally would not advocate mixing the two threads, but go ahead if you must.

For several decades I raced on the track using Dura Ace and Suntour cogs with English threading on my Campy Italian threaded track hubs w/o any problems. I think the warnings are exagerated.

As far as track components go, the only thing that you shouldn't mismatch between those two brands are the lockrings because they have different threading.

Campy cogs are ISO thread; it's just the lockrings that are different.


Source: Sutherland's 4th Edition

I have a surly cog on my italian threaded campy pista hub now, and want to change it to a DA, I think. Was thinking of changing front chain ring to DA to match (the chain ring is currently a 48t campy, but 3/32). Im
Tired of maintenance and noise from the chain, which is now a new izumi mod V. Chain line is straight, btw.

It's summer. Ride your bike. You'll be fine.

This is a rainy November day question.

While that may be the best advice the OP got in this thread - just to add to the Campag hub/cog threading size confusion...

I can state from owning a set that Campy did, at least at some time in the past, offer rear track hubs & cogs with English threading:

AFAIK, the cogs were always ISO/English thread, but hubs could also be had in metric (35mm x 1mm) thread for a 3rd party metric thread cog.

Actually, ISO and English are not exactly the same. English, also called British, is 1.370" diameter threading, whereas ISO is 1.375". Italian is 1.378", which is much closer to ISO than English/British.

Except Italian thread pitch is 55° versus ISO/English 60°:


Source: Sutherland's 4th Edition

But we're really picking nits here, aren't we?

Actually, the term "pitch" refers to the distance between threads, which is 24TPI in all three cases. Thread angle is not the same thing as thread pitch.

Everyone should down a bottle of rum before reading this thread

Even though its morning, soon as I finish post this I may very well go hit the bottle of rum sitting in the back of my liquor cabinet. Surely this thread has taken a direction the OP never intended but discussions involving Campag bits always get...interesting?

The reason I ended up with those BSA parts I pictured yesterday is that in the throes of wanting to make my bike a full-blooded Italian build, I originally bought a Campy pista hub that the seller stated took Italian threaded cogs. I have quite a few English thread cogs laying around so for curiosity sake tried a couple on it. They did not really want to go on and I was not going to chance ruining the thing so did not force anything. I consider myself lucky to have found someone willing to trade the hub I've got now for it.

As part of researching further, I ran across some old Campagnolo catalogs online and found that Super Record Pista hubs were made in 3 threadings: 35x24F, 34.7x1M and 1.37x24F. I also found several different thread patterns for available lockrings. Campagnolo's new lockrings are 1.32x24F, which I could not determine for sure if it fits on old SR Pista hubs.

The seeming multitude of thread varieties I found for Campy pista hubs, cogs, and lockrings finally got to be too much for me so I ended up just sticking with my Jap wheels. Threads like this reinforce my decision.

Now to find that Rum...or maybe I should have some Bourbon instead?