Zipp stem compatibility issues?

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fizzaz
Posts: 274
Joined: Wed Nov 07, 2018 5:02 pm

by fizzaz

In my case, all of SC SLs have left more marks than the carbon one I mentioned earlier. The clamp area seems to always dig into the surface paint/carbon no matter how evenly torqued.

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steveadore
Posts: 386
Joined: Wed Mar 04, 2020 10:01 am

by steveadore

fizzaz wrote:
Mon Jun 05, 2023 10:41 pm
In my case, all of SC SLs have left more marks than the carbon one I mentioned earlier. The clamp area seems to always dig into the surface paint/carbon no matter how evenly torqued.
With my SC (non-SL), which I have in the picture, it has already left marks even without mounting the faceplate and tightening the bolts. It's just marks from pushing the bar to click into position (in which position it is then almost fixed, without the faceplate, making it difficult even to rotate the bar to different angles)

TobinHatesYou
Posts: 12456
Joined: Mon Jul 24, 2017 12:02 pm

by TobinHatesYou

I experienced this with my Zipp SL Sprint stem. I saw it as a minor annoyance and it didn't cause anymore superficial marring to the clamping area of my bars than any other stem would.

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wheelbuilder
Posts: 1193
Joined: Wed Feb 08, 2017 2:10 am

by wheelbuilder

It's also a claimed strength feature to have a slip-fit type connection of bar to stem. I have the carbon speed sl and it has the same installation behavior with Ritchey carbon Evo curve and Bontrager carbon xxx bars. Never a problem and certainly nothing to fret about. Road cycling is inherently dangerous if done correctly.
Never cheer before you know who is winning

steveadore
Posts: 386
Joined: Wed Mar 04, 2020 10:01 am

by steveadore

wheelbuilder wrote:
Tue Jun 06, 2023 6:30 am
It's also a claimed strength feature to have a slip-fit type connection of bar to stem. I have the carbon speed sl and it has the same installation behavior with Ritchey carbon Evo curve and Bontrager carbon xxx bars. Never a problem and certainly nothing to fret about. Road cycling is inherently dangerous if done correctly.
But is that slip-fit or pressfit (as in press it in hard and the forget about rotating the bar unless you want to damage its surface)? :?:

PoorCyclist
Posts: 783
Joined: Wed Dec 07, 2011 1:26 am
Location: California's country side

by PoorCyclist

I think they made the carbon part a little tighter, because it is flexible and to anticipate for wear.

I don't see the rationale though using that stem and a relatively cheap aluminum bar? If you used a carbon bar, then both gives in a little (as in indentation of the bar, after tightening). Then there would be less stress on the stem giving in to aluminum.

steveadore
Posts: 386
Joined: Wed Mar 04, 2020 10:01 am

by steveadore

PoorCyclist wrote:
Tue Jun 06, 2023 4:17 pm
I think they made the carbon part a little tighter, because it is flexible and to anticipate for wear.

I don't see the rationale though using that stem and a relatively cheap aluminum bar? If you used a carbon bar, then both gives in a little (as in indentation of the bar, after tightening). Then there would be less stress on the stem giving in to aluminum.
I got the carbon stem at a great price, and I needed a minus 12 degree one. That's the only reason I went for it. It's for a gravel bike, so there's no need to a carbon bar (low pressure high-volume tubeless tires will take care of comfort).
My main problem is that the aluminum stem is even tighter on the same bar as the carbon stem (just as a reminder: all 3 are the same brand).

PoorCyclist
Posts: 783
Joined: Wed Dec 07, 2011 1:26 am
Location: California's country side

by PoorCyclist

Do you have a caliper you can measure the interface at the bar? I think it may be more than 31.8mm or whatever it is spec'd

steveadore
Posts: 386
Joined: Wed Mar 04, 2020 10:01 am

by steveadore

PoorCyclist wrote:
Tue Jun 06, 2023 7:08 pm
Do you have a caliper you can measure the interface at the bar? I think it may be more than 31.8mm or whatever it is spec'd
My digital caliper may not be a high-precision model (it was cheap), but it shows 31.8mm vertically (which is what matters for the clamping area), maybe a bit over that horizontally (but I didn't rotate the bars 90 degrees, so the horizontal excess, if there is any, does not matter).
And, as I said, the bars slot in perfectly in the 3 Specialized stems I've tried.
What's even more puzzling is that the Zipp stems work fine with other bars too.

So it's just the combination of the Zipp bars with the Zipp stems (maybe they are designed to fit really snugly, while my other bars are slightly under 31.8 and my other stems are slightly over 31.8). I'm just clueless and Zipp customer service could not really help

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