Do you need spacers?

[veloduffer]

I'm getting a Fierte and with its long head tube, the my fit appears not to need a spacer between the stem and headset using a -17 stem.

Pardon me for asking (being from the old quill world), do you need to have a spacer or can the stem go right on top of the headset (without damage)?

[AngryScientist]

i'm not an expert, but i'm going to guess that it's going to depend at least partially on what type of stem you are using and the interface with the bottom of the stem and the top of the headset. if there is a clean, flush fit, i cant see why you would need a spacer there.

[AndrewS]

There is discussion on another spacer thread today that Trek blamed a bunch of steerer failures on the stem sitting right on the headset. Maybe the clamping is a factor?

That fit sounds odd. Seems like tall headtube for you on a custom bike. Is there another model that isn't so tall?

[veloduffer]

There is discussion on another spacer thread today that Trek blamed a bunch of steerer failures on the stem sitting right on the headset. Maybe the clamping is a factor?

That fit sounds odd. Seems like tall headtube for you on a custom bike. Is there another model that isn't so tall?

I bought this Fierte (all carbon) on ebay, and it is stock geometry. Headtube is 19cm on a 58cm (56.5cm virtual top tube) bike. Plus the bb drop is 8cm, so getting to my 5cm saddle-handlebar differential (I use a 75.5cm saddle to bb height) is going to be close.

[David Kirk]

I think the reason that many makers want a spacer is to allow the steerer to have a longer radius natural flex to it and less of a hinging at the headset type of deal.

I personally never design bikes to run without spacers because this gives no room to lower the stem. And if the stem is already a -17° rise then you have even fewer options should you need/want to go lower.

dave

[crownjewelwl]

http://www.bikerumor.com/2010/06/23/broken-trek-carbon-steerer-tubes-result-of-the-wrong-stems/

[AndrewS]

Well, would it really hurt to have your bars 5mm higher than optimal?

[Dave]

It won't hurt a thing to use no spacers, in this mechanical engineer's opinion. I did it with both of the Colnago C-40 frames that I owned. There's always some top cap thickness and you can choose from headsets as low as 25mm in height to 30+.

[T.J.]

That's how I run my Super6


http://i283.photobucket.com/albums/kk306/girofan/photo-125.jpg

[veloduffer]

That's how I run my Super6


http://i283.photobucket.com/albums/kk306/girofan/photo-125.jpg

What headset is that? Integrated?

[veloduffer]

It won't hurt a thing to use no spacers, in this mechanical engineer's opinion. I did it with both of the Colnago C-40 frames that I owned. There's always some top cap thickness and you can choose from headsets as low as 25mm in height to 30+.

I researched a bit on headsets (generally I've used Chris King) and the Cane Creek Zero Stack (ZS) headsets looking interesting (Cane Creek Zero Stack (http://www.canecreek.com/component-headsets?browse=type&type=zero-stack&product=110-ZS)). I haven't found any reviews but in general I've heard good thinks about their headsets. Any opinions?

[bluesea]

I researched a bit on headsets (generally I've used Chris King) and the Cane Creek Zero Stack (ZS) headsets looking interesting (Cane Creek Zero Stack (http://www.canecreek.com/component-headsets?browse=type&type=zero-stack&product=110-ZS)). I haven't found any reviews but in general I've heard good thinks about their headsets. Any opinions?


I can't name them right now, but there are truer zero stack solutions available. Cane Creek's 8mm upper stack ht is pretty common, as I have a 8mm FSA on my Cervelo R3 with 5mm below, and 10mm above. OTOH, Cervelos epoxied Al sleeved compressor looks like it provides a good amount of support.

[oldpotatoe]

I'm getting a Fierte and with its long head tube, the my fit appears not to need a spacer between the stem and headset using a -17 stem.

Pardon me for asking (being from the old quill world), do you need to have a spacer or can the stem go right on top of the headset (without damage)?

I would use at least a thin, like 1mm, spacer..

[yeastor]

This is a link to a Velonews article about spacers under stems -- basically the Trek recommendations mentioned above. Says minimum of 5 mm of spacer under the stem.

http://velonews.competitor.com/2010/06/news/steered-wrong-racers-concerned-about-broken-carbon-steerer-tubes_121389

Peter

[thwart]

Would seem to me that with no spacer, if you have a fairly flat headset top (like some integrated ones---see pic above) combined with a broad stem base, it could lead to some pretty significant 'hinge' force on the steerer at that point.

[jeo99]

That's how I run my Super6


http://i283.photobucket.com/albums/kk306/girofan/photo-125.jpg

T.J.
You now have a SuperSix? I thought you loved your CAAD9?

:beer:

[jeo99]

What headset is that? Integrated?

Yes it is integrated. I have one as well.

:beer:

[Dave]

Zero stack is not an option for frames made to use conventional headsets. The head tube ID requirement is not the same.

[veloduffer]

Zero stack is not an option for frames made to use conventional headsets. The head tube ID requirement is not the same.

Thanks. I'm an old school guy who hasn't kept up with all the technology.

[darnellrm]

Actually, the more spacers you use, the more force applied to the steerer at the top of the headset. It's called leverage.



Would seem to me that with no spacer, if you have a fairly flat headset top (like some integrated ones---see pic above) combined with a broad stem base, it could lead to some pretty significant 'hinge' force on the steerer at that point.

[Mike748]

Actually, the more spacers you use, the more force applied to the steerer at the top of the headset. It's called leverage.

Yeah but its a trade off between shear and flex. More spacer gives more flex, less spacer more shear.

[RPS]

I have to admit I can’t follow the hinge, flex, or shear concerns being discussed above as they are affected by a spacer. The only significant benefit I can visualize at this point to adding a spacer is that it separates loads from the stem and headset so their cumulative effect becomes less concentrated. Spreading the loads apart should lower maximum stresses.

Personally I don’t want a bike so marginal in design that it has to be assembled with such care and precision to make it safe. I speculate much of the issue is driven by incremental weight savings (stem and/or steerer depending on who is pointing fingers), and that’s not worth it to me.

[Ralph]

I would use at least a thin, like 1mm, spacer..

I would do the same.