small spacer above stem : required or not?

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11.4
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by 11.4

It seems that the expander not only helps set pre-tension but also provides a surface for the steer wall to compress against (with pressure applied by the stem clamp). Cannondale argues this point by saying that the top of the steer should be inset in the stem, but their own expanders aren't as tall as their stems anyway. And if one changes stems (which is not uncommon) then all bets are off.

I've seen people riding with 4 cm of spacers above the stem, and in this case the preload expander can be completely clear of the stem and provides no internal support to the stem clamp. Obviously in this thread we're fighting over 5 mm versus 2 mm versus none, but it should be pointed out that in Cannondale's world there are a lot of weird things done by bike owners. This isn't to say that one approach is actually right or not, but to suggest that manufacturer recommendations may have no value if one is switching any related component on the bike -- which even the manufacturer would agree is necessary at times.

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bikerjulio
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by bikerjulio

And if one changes stems (which is not uncommon) then all bets are off.


I just measured three different common brands on my bikes and they all come in the 40-42mm height range. Not exactly an earth shattering difference.

Cannondale plugs are pretty close to that length, and for sure are reinforcing the top of the steerer if correctly installed, which is the whole point of this thread.

And yes, people can, and do ignore instructions.
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Poulidor
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by Poulidor

bikerjulio wrote:
Poulidor wrote:
mattr wrote:Yes, you are doing it wrong, if it's flush, you can't preload the headset properly.
And the discussions for and against leaving the steerer proud of the stem are already up there.


Most likely you are perfectly correct. However. I'm referring to King and Campagnolo headsets only. I have never, in at least over a decade and many miles and bicycles, had an issue with a stem/headset/steer tube installation. That said, it might be that I cut the top of the steer tube short enough from the top of the stem to make it work.

In any case, I'm pleased not to have had a problem because I don't like the look of spacers over the stem.


The issue under discussion has nothing do do with the brand of headset being used. Please pay attention.


I may be new here but I don't need you to tell me what to do. Some of the posts are referring to Cannondale and to how different brands and headset/head tube arrangements may or may not require a spacer over the stem. Which is why I was specific. In any case, you're bullying the wrong person, Julio.

11.4
Posts: 1095
Joined: Tue May 23, 2006 4:33 am

by 11.4

bikerjulio wrote:
And if one changes stems (which is not uncommon) then all bets are off.


I just measured three different common brands on my bikes and they all come in the 40-42mm height range. Not exactly an earth shattering difference.

Cannondale plugs are pretty close to that length, and for sure are reinforcing the top of the steerer if correctly installed, which is the whole point of this thread.

And yes, people can, and do ignore instructions.


I was actually measuring three stems I had in front of me: A 3T at 42, a Thomson X4 at 48, and a Moots at 56. Throw in measurements for a couple others, the dimensions varied enough so that the expander could be supporting one clamp bolt but not the other end of the stem. Plus for all of this, more critical than whether the steer is cut short or long is whether the expander is positioned centered within the stem or down below it. If the expander is set low in the steer, the height of the cut on the steer starts to become a bit irrelevant if the idea is to match the expander, the steer, and the stem.

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RBJ2206
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by RBJ2206

I had a spacer above the steerer on my supersix evo but after reading this I am going to remove it and cut steerer down.

jorisee01
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Joined: Mon May 04, 2015 8:22 pm

by jorisee01

RBJ2206 wrote:I had a spacer above the steerer on my supersix evo but after reading this I am going to remove it and cut steerer down.


Just cut mine as well!


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bikerjulio
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by bikerjulio

Poulidor wrote:
bikerjulio wrote:
Poulidor wrote:
mattr wrote:Yes, you are doing it wrong, if it's flush, you can't preload the headset properly.
And the discussions for and against leaving the steerer proud of the stem are already up there.


Most likely you are perfectly correct. However. I'm referring to King and Campagnolo headsets only. I have never, in at least over a decade and many miles and bicycles, had an issue with a stem/headset/steer tube installation. That said, it might be that I cut the top of the steer tube short enough from the top of the stem to make it work.

In any case, I'm pleased not to have had a problem because I don't like the look of spacers over the stem.


The issue under discussion has nothing do do with the brand of headset being used. Please pay attention.


I may be new here but I don't need you to tell me what to do. Some of the posts are referring to Cannondale and to how different brands and headset/head tube arrangements may or may not require a spacer over the stem. Which is why I was specific. In any case, you're bullying the wrong person, Julio.


I'm not in the habit of bullying, and I think my record shows it.

The thread is discussing an often confusing issue, to which I and others are trying to add clarity, so when a post comes on which adds to confusion, that's not a good thing.

Cannondale makes bikes. Campy and King make headsets. Cannondale uses Campy headsets one way, with a Cannondale expander and top cap, and their own set of directions. Others may also use Campy headsets, but with a different expander and a different set of directions. The issue under discussion is nothing to do with whether or not a Campy headset was used. Likewise with King headsets.

Hope this clarifies things.
There's sometimes a buggy.
How many drivers does a buggy have?

One.

So let's just say I'm drivin' this buggy...
and if you fix your attitude you can ride along with me.

http://www.youtube.com/watch?v=GekiIMh4ZkM

RyanH
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by RyanH

I've always cut it below the stem using Enve 1.0 forks, which is considered a thinner walled steerer tube. The only issue I've ever had was when I was 4mm below the top of the Extralite stem and it would shimmy under high torque due to insufficient clamping area.

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djm
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by djm

mattr wrote:Yes, you are doing it wrong, if it's flush, you can't preload the headset properly.
And the discussions for and against leaving the steerer proud of the stem are already up there.


You can, if you use a spacer which you remove after you have torqued the stem.

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