Zipp stem compatibility issues?

[steveadore]

I just got a Zipp Sprint SL carbon stem, but when I try to install my Zipp Service Course SL70 Xplore handlebars, I need to put some pressure pushing the bars into the clipping area of the stem. It's almost as if there was a sizing/diameter issue, though both are nominally 31.8 and from the same manufacturer. Out of curiosity, I've tried a cheaper set of alloy Zipp Service Course stem, and the problem is exactly the same: it takes a bit of effort to push the bars into the half-open clamp of the stem (i.e. faceplate is removed), and once the bars are pushed in place, it's not that easy to move or rotate them.
Is this something Zipp consciously designed, similar to some other brands (I think Syntace or Ritchey designs some stems so that the clamping area extends a bit beyond 180 degrees, so once the bars are pushed in there, they don't fall out even if the faceplate is not installed)?

[polpy]

It was the same on a Zipp SL Carbon Stem and SL70 Aero Bars 2 or 3 years ago, so i guess its normal. Never had issues though.

[steveadore]

It was the same on a Zipp SL Carbon Stem and SL70 Aero Bars 2 or 3 years ago, so i guess its normal. Never had issues though.

Thanks, so this seems to be a Zipp feature then. I'm not sure I like it, to be honest. The black finish on my brand new alloy Zipp bars has already worn a bit just after trying them in the 2 Zipp stems (I haven't even mounted the faceplate). And I guess it will get worse once I rotate them for fine adjustment

[polpy]

It was the same on a Zipp SL Carbon Stem and SL70 Aero Bars 2 or 3 years ago, so i guess its normal. Never had issues though.

Thanks, so this seems to be a Zipp feature then. I'm not sure I like it, to be honest. The black finish on my brand new alloy Zipp bars has already worn a bit just after trying them in the 2 Zipp stems (I haven't even mounted the faceplate). And I guess it will get worse once I rotate them for fine adjustment

I usually run my Zipp Cockpits with Alloy Stems and Carbon Bars as i dont see any benefit in the carbon stems...

[steveadore]

It was the same on a Zipp SL Carbon Stem and SL70 Aero Bars 2 or 3 years ago, so i guess its normal. Never had issues though.

Thanks, so this seems to be a Zipp feature then. I'm not sure I like it, to be honest. The black finish on my brand new alloy Zipp bars has already worn a bit just after trying them in the 2 Zipp stems (I haven't even mounted the faceplate). And I guess it will get worse once I rotate them for fine adjustment

I usually run my Zipp Cockpits with Alloy Stems and Carbon Bars as i dont see any benefit in the carbon stems...

Hm, but I experienced the same issue with the Zipp Service Course alloy stem too. Are the Zipp carbon bars slightly narrower in diameter at the clamping area? Judging by the pressure needed for pushing the alloy Zipp bars into the clamping slot on both alloy and carbon Zipp stems, I'm not sure I would risk carbon bars.

It's definitely the Zipp stems. I've tried the same Zipp bars with an S-Works stem, and it's just like most other regular stem/bar clamp interfaces: no effort needed, though of course that also means that the bars would fall out of the stem clamp unless the faceplate is also in place

[polpy]

It was the same on a Zipp SL Carbon Stem and SL70 Aero Bars 2 or 3 years ago, so i guess its normal. Never had issues though.

Thanks, so this seems to be a Zipp feature then. I'm not sure I like it, to be honest. The black finish on my brand new alloy Zipp bars has already worn a bit just after trying them in the 2 Zipp stems (I haven't even mounted the faceplate). And I guess it will get worse once I rotate them for fine adjustment

I usually run my Zipp Cockpits with Alloy Stems and Carbon Bars as i dont see any benefit in the carbon stems...

Hm, but I experienced the same issue with the Zipp Service Course alloy stem too. Are the Zipp carbon bars slightly narrower in diameter at the clamping area? Judging by the pressure needed for pushing the alloy Zipp bars into the clamping slot on both alloy and carbon Zipp stems, I'm not sure I would risk carbon bars.

It's definitely the Zipp stems. I've tried the same Zipp bars with an S-Works stem, and it's just like most other regular stem/bar clamp interfaces: no effort needed, though of course that also means that the bars would fall out of the stem clamp unless the faceplate is also in place

My Zipp Alloy stem does not have the same issue when i think about it.

[steveadore]

Thanks, so this seems to be a Zipp feature then. I'm not sure I like it, to be honest. The black finish on my brand new alloy Zipp bars has already worn a bit just after trying them in the 2 Zipp stems (I haven't even mounted the faceplate). And I guess it will get worse once I rotate them for fine adjustment

I usually run my Zipp Cockpits with Alloy Stems and Carbon Bars as i dont see any benefit in the carbon stems...

Hm, but I experienced the same issue with the Zipp Service Course alloy stem too. Are the Zipp carbon bars slightly narrower in diameter at the clamping area? Judging by the pressure needed for pushing the alloy Zipp bars into the clamping slot on both alloy and carbon Zipp stems, I'm not sure I would risk carbon bars.

It's definitely the Zipp stems. I've tried the same Zipp bars with an S-Works stem, and it's just like most other regular stem/bar clamp interfaces: no effort needed, though of course that also means that the bars would fall out of the stem clamp unless the faceplate is also in place

My Zipp Alloy stem does not have the same issue when i think about it.

Hm, which one do you have? I've tried the cheaper Zipp Service Course (not SL), which is 6061 alloy.

[polpy]

I have the alloy SL with sl70 ergo currently on a bike.

[steveadore]

So, Zipp customer service is telling me this is not quite normal. I'm perplexed as I have the same issue with 2 Zipp stems (it's highly unlikely that both are out of spec). And the Zipp handlebars must be in spec too, because with several other stems (I had a couple of Spesh stems lying around in a box) they fit normally.
Here's a couple of photos illustrating the issue: Note the gap between the handlebar and the stem. Even so (i.e. not pressed fully against the stem), it's already locked in position, so it doesn't fall off when turned vertically down without the faceplate installed.

[fizzaz]

I've got like 5 of these stems and its never been a problem.

[Sock3t]

Fake bars? Zipp quality control? I personally would not ride that.

[steveadore]

Fake bars? Zipp quality control? I personally would not ride that.

No, they are not fake. But I'm definitely disappointed in their quality control. I still cannot figure out whether it's the stems or the bar. The bar fits my non-Zipp stems, but the Zipp stems also fit some mountain bike bars (same 31.8mm standard) I've tried them with. So it's just the bad fit of the Zipp bar with my 2 Zipp stems. Never had Zipp before, and I'm not sure I will after this negative experience

[steveadore]

I've got like 5 of these stems and its never been a problem.

Which stem did you have? The cheapo Zipp Service Course alloy or the Sprint SL carbon one?

[fizzaz]

I've got several of the Service Course SLs that this wasn't an issue with, but I just went and unbolted the Carbon Sl Speed and it looks like it *does* have this sort of behavior. That said, it hasn't been a problem and it takes very little pressure for it to "click" the bar into the stem. I wouldn't worry about it unless it was a significant mismatch.

[steveadore]

I've got several of the Service Course SLs that this wasn't an issue with, but I just went and unbolted the Carbon Sl Speed and it looks like it *does* have this sort of behavior. That said, it hasn't been a problem and it takes very little pressure for it to "click" the bar into the stem. I wouldn't worry about it unless it was a significant mismatch.

Thanks. I'm not sure, to be honest. Of course it doesn't take too much pressure, but once it "clicks" into position, it's not easy to rotate the bar, and (as my photo shows), it is locked in and does not fall out even without the faceplate installed. I just don't really feel safe using it like this as the stem had already left some surface marks in the black finish of the bar.