# Spacer above the stem necessary?



## 32and3cross (Feb 28, 2005)

boleiro said:


> Just dropped my bike off at my LBS to get my carbon fork steerer cut and the guy said I need to have at least a 5mm spacer below the stem and 5mm spacer above. Is this absolutely necessary? I hate the look of spacers above the stem. totally ruins the look. I'm also trying to keep the rise as low as possible. I would like to go even lower if I could find a damn dustcap that was lower. While I have seen some bikes with this, I have seen many more with no spacers above the stem.
> 
> Any words of wisdom? I'd like to catch him before he does anything.


Above I understand (to keep you from crusinging the steerer by having load spread to the max. Below makes no sense at all that I can tell.


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## Mike T. (Feb 3, 2004)

With no spacer above the stem, the steerer tube needs to be 3mm down below the stem top for headset adjustment purposes. But with a carbon steerer this isn't great as the stem tightening tends to deform the CF tube. With the steerer running clear through the stem there is no steerer pinching action. A 5mm spacer is enough. Your LBS is full of it if they say a spacer below the stem is necessary.


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## redlude97 (Jun 29, 2010)

boleiro said:


> damn, it was the spacer above that I have problems with. but thanks. you learn something everyday.
> 
> how many people out there are doing it wrong!


Not necessarily wrong, they probably just have aluminum steerer tubes


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## AvantDale (Dec 26, 2008)

Its just to make sure that stem clamps all of the steerer.

Some companies use compression plugs that reinforce the steerer internally and those do not require the spacer above the stem.


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## tom_h (May 6, 2008)

I agree that no spacers above stem looks sleeker. Spacers above stem depends on the manufacturer's design. 

Eg, Specialized's carbon steerer tubes & expander plugs are designed to be compatible with no spacers above stem. The plug assembly resists crushing at the top of the stem.


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## Camilo (Jun 23, 2007)

Manufacturer's instructions guys!

That's all there is. Depends on the fork and the plug/top cap used.

No single "right" answer.


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## Mersault (Jan 3, 2005)

I've got a 2mm spacer above my stem on both my bikes. The set up actually looks like a stepped top cap. Something to think about it if aesthetics are on you mind.


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## boleiro (Jun 11, 2010)

Just dropped my bike off at my LBS to get my carbon fork steerer cut and the guy said I need to have at least a 5mm spacer below the stem and 5mm spacer above. Is this absolutely necessary? I hate the look of spacers above the stem. totally ruins the look. I'm also trying to keep the rise as low as possible. I would like to go even lower if I could find a damn dustcap that was lower. While I have seen some bikes with this, I have seen many more with no spacers above the stem. 

Any words of wisdom? I'd like to catch him before he does anything.


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## boleiro (Jun 11, 2010)

damn, it was the spacer above that I have problems with. but thanks. you learn something everyday.

how many people out there are doing it wrong!


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## gpcyclist25 (Mar 22, 2011)

boleiro said:


> damn, it was the spacer above that I have problems with. but thanks. you learn something everyday.
> 
> how many people out there are doing it wrong!


So is the answer "sometimes"? I know in the Park Tool repair book they highly recommend the spacer above, even with the compression plug.

So its still unclear.


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## PJ352 (Dec 5, 2007)

If you provide specifics as to make/ model of fork, you'll be more apt to get relevant info. 

As has been mentioned, the 'correct' answer depends on the manufacturers specs.


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## boleiro (Jun 11, 2010)

sounds like most manufacturers recommend a spacer above the stem. I guess I can live with the spacer above the stem. But I'm going to try both spacers above the stem. Sounds like a spacer between the stem and dust cap isn't necessary. 

thanks all, almost done with this build, just in time for the saturday ride.


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## frdfandc (Nov 27, 2007)

PJ352 said:


> As has been mentioned, the 'correct' answer depends on the manufacturers specs.



This is the correct answer. Depends on the manufacturer of the fork. 


I know with Fuji bikes equipped with carbon forks with carbon steerer tubes use a compression plug that has an alloy lip that goes over the top edge of the steerer tube, so no spacer is required above the stem.


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## Len J (Jan 28, 2004)

Couple more possible reasons.. I have one above the stem on my steel steerer tube Sachs because I intend to have the bike for a very long time and would like the flexability to raise the stem as I age. In addition, more steerer can make the bike easier to sell.

Len


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## GA1911 (May 4, 2010)

I have an Enve 2.0, and they recommend a 5mm above the stem. They also use a compression plug which is supplied with the fork. The research I did found that "most" carbon steerer/fork companies recommend something above stem. Check with your manufacturer.


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## baker921 (Jul 20, 2007)

I asked this a few months back and no one suggested putting a spacer above the stem could do any harm.


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## Eric_H (Feb 5, 2004)

Note that Trek also recommends a 5 mm spacer between the fork cap and the stem on its carbon forks. Don't tell that to Fabian.


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## danl1 (Jul 23, 2005)

Above the stem has been adequately discussed. I'll talk about below.

The answer is - of course - it depends.

Depending on the shapes of the stem and the top cap, they can interfere with one another in such a way as to drive the top cap out of square with the bearings. It's more common if the stem is angled down, but can happen on some other designs, too. A small spacer in there can make sure everything runs parallel.


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## PoorCyclist (Oct 14, 2010)

On my steerer.. the plug is metal and it appears to give good reinforcement to the top of the steerer.

I was going to shift it down and do the 5mm on top thing, but once I saw that decided not to.


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## AC0 (Aug 19, 2010)

This is what Trek has to say:

Below the stem on all steerers
Always place at least one 5mm spacer below the stem. This spacer is in addition to the bearing cover (Figure 1), which must be at least 5mm. If the stem rests against the bearing cover, a point load is created on the steerer that could eventually cause the steerer to break. 

AC


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## MR_GRUMPY (Aug 21, 2002)

5MM seems like a lot.
I have a 1mm below, and a 3 above (because i didn't want to cut the steerer short, and I'm too lazy to go back and cut it again)


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## Eric_H (Feb 5, 2004)

AC0 said:


> This is what Trek has to say:
> 
> Below the stem on all steerers
> Always place at least one 5mm spacer below the stem. This spacer is in addition to the bearing cover (Figure 1), which must be at least 5mm. If the stem rests against the bearing cover, a point load is created on the steerer that could eventually cause the steerer to break.
> ...


Yeah, this is what I was trying to say earlier but did a poor job of it. Interesting to note most riders on Radioshack and Leopard have the stem on the top of the bearing cap though.


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## chas0039 (Jun 26, 2007)

I would guess that below as well as above is always safer and stronger, especially with carbon. Without, you always take your chances. Might be OK, sometimes it might not. I always do both.


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## boleiro (Jun 11, 2010)

AC0 said:


> This is what Trek has to say:
> 
> Below the stem on all steerers
> Always place at least one 5mm spacer below the stem. This spacer is in addition to the bearing cover (Figure 1), which must be at least 5mm. If the stem rests against the bearing cover, a point load is created on the steerer that could eventually cause the steerer to break.
> ...


actually, in my original post the LBS I spoke of is a Trek Store. So, they are sticking to Trek Doctrine. 

After getting the bike back with the steerer cut with a 5mm spacer above and below the stem, It doesn't look as bad as I thought it would. Still not as clean as no spacer up top, but I'll ride this way for awhile and see. 

I'm thinking if its still an issue I can get one of the compression plugs that are designed to support the steerer along its entire length to get rid of the top spacer.


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## atimido (Jun 17, 2009)

boleiro said:


> damn, it was the spacer above that I have problems with. but thanks. you learn something everyday.
> 
> how many people out there are doing it wrong!


No. I had a disagreement about this with a bike store mechanic, and it took me bringing in the manufacturer’s instructions for the carbon fiber fork with specific notes dictating how to cut the steerer-tube. The directions said _Do Not_ leave a spacer above the stem and below the steerer-tube cap (with different wording). The bike mechanic told me the manufacturer was wrong. The manufacturer was wrong... Yea right! I told him that if he was going to do the job, he was going to do it via the instructions so if anything happened and the steerer-tube broke everything would still be in accordance with the recommendation of the manufacturer. Check with the manufacturer of the fork and see what they recommend. If they recommend 5mm above the stem, then do it. If not, then don't.


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## namillis (Jun 30, 2010)

I agree here. I typically wouldn't use a spacer above the stem but if the manufacturer says to do it then by all means do it. The only loss is that a little weight is added and it doesn't look as sleak.


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