[Atomic_Frog]

I have a set of spare 11sp Athena Ultrashifts (yes, the older Ultra, not the Power shift) and I need a new derailleur to piece together another bike.
Can I "cheap out" and get a medium cage 10sp Veloce? Or do I need 11sp Athena?

Campy site just flat out says no, you can't upgrade 10sp to 11sp without specifics, but other sites claim the 10s and 11s rears have the same pull ratios so as long as the shifter+cassette is 11s, I can do it. Then I also hear I can't use medium cage Potenza with anything else but Potenza?
Which of these is true?

My other option is to just get new 10s shifter+derailleur as I don't really need 11s (have it on another bike, doesn't really make a difference) and I prefer the all-silver shifter not the carbon look on my 11sp Athena.

 

[edjy]

Others may claim differently, but the ~2015ish 10 speed derailleurs with the wrap around outer plate like original 11 spd have the same narrow pulleys as 11 and the 10spd shifters are supposed to be compatible with all 10spd derailleurs pull-wise. This leads me to conclude that an old wide pulley 10spd derailleur will be sluggish shifting 11 since the caqe with wide pulleys will not hit the chain as quick, but that the centering will be good and that likely 11spd derailleur could shift 10 fine. You could do what you are planning but you may have quite a few incomplete shifts.

I have a set of spare 11sp Athena Ultrashifts (yes, the older Ultra, not the Power shift) and I need a new derailleur to piece together another bike.
Can I "cheap out" and get a medium cage 10sp Veloce? Or do I need 11sp Athena?

Campy site just flat out says no, you can't upgrade 10sp to 11sp without specifics, but other sites claim the 10s and 11s rears have the same pull ratios so as long as the shifter+cassette is 11s, I can do it. Then I also hear I can't use medium cage Potenza with anything else but Potenza?
Which of these is true?

My other option is to just get new 10s shifter+derailleur as I don't really need 11s (have it on another bike, doesn't really make a difference) and I prefer the all-silver shifter not the carbon look on my 11sp Athena.

 

[Atomic_Frog]

So my rebuild is complete:
* Athena 11 Ultrashift (not Powershift)
* Veloce 10sp medium cage
* Miche Primato 11sp 12-29
* KMC 11sp chain
* 52-39 Campagnolo 10sp / TA Specialties
* Miche dual-pivot brakes

Mostly selected for low cost and looks (i.e. silver / metallic). I kept the original Chorus cranks, they seemed fine.
Braking is slightly mushy compared to my Athena skeleton or the previous Veloce I was used to but I could also say it offers excellent modulation for those with less sensitive hands. No real complaints.

Shifting works out fine. Seems to be quite quiet and I've had no problems going up and down the entire range at the back. The front works pretty well. Have not had to deal with any chain slap even though it feels quite slack. I sized the chain according the what Park Tool said was recommended for Campy.

 

[Finx]

It's a mortal sin to post details about a new build without pictures.

 

[Bee-an-key]

If you read Leonard Zinn he tackles a lot of questions about combining brands and cog sets. The manufacturer is always going to recommend matchy matchy for optimal performance, and to sell new stuff. Zinn points out that much of the stuff works together mixed, just not as crisp but no reason to throw out the old and spend money on the new.

 

[Atomic_Frog]

It's a mortal sin to post details about a new build without pictures.

Aaah yeah, sorry about that. Let me see if I can rectify that shortly. Been too busy riding it to take snaps!
It's been fantastic, it's different but doesn't really feel slower than any of my newer bikes. Took it up a bit of a climb on a local mountain. My fastest time back when I was young (oooh, many moons ago) was round about 19 minutes and we were really pushing it back in the day. Despite hauling way too much weight now and too little training, me 'n the De Rosa managed to haul over the top only a few minutes slower. It felt really good and I think with a few weeks under my belt, I could easily lop off that extra time.

I did poke around all before doing this change, Sheldon Brown's, Zinn's and the like but there didn't seem to be any definitive answer as to how well this particular combo would work. Just wanted to document it here in case somebody else tries something similar.

 

[smokva]

I have a set of spare 11sp Athena Ultrashifts (yes, the older Ultra, not the Power shift) and I need a new derailleur to piece together another bike.
Can I "cheap out" and get a medium cage 10sp Veloce? Or do I need 11sp Athena?

I have Ultrashift 11 speed shifters (Chorsu, but all Ultrashift 1st gen should be the same) working on one of my bikes with Veloce 10 speed RD.

So, yes its compatible.