small spacer above stem : required or not?

[Delorre]

Is there a consensus about this? A lot of people leave a small 5mm spacer above the stem, but is this really required? I prefer the looks of a just a flush topcap above the stem. OK, this doesn't leave any room to higher the stem afterwards if needed, but that's a choice to make

[xena]

I think there was some kind of issue with Treks. You had to leave a spacer, warranty etc.
But otherwise go flush. Both my bikes are.

[Bogan]

As long as the steerer extends past the top of the stem it should be ok. I assume we are referring to a carbon steerer. If the steerer does not extend past the top of the stem, you are risking cracking the steerer when you tighten up the stem. One of the weight weenie manufacturers, Tune or AX, manufacture a top cap that also acts as a spacer, about 2mm if I remember correctly.

[Delorre]

Ok, 2 answers answers and both different. Good start We are talking carbon for clarity.

[Stolichnaya]

If the 5 mm spacer is a visual problem for you, go with a 2.5 mm spacer.
KCNC makes one that practically dissapears. There are some others that make thin spacers.

[bikerjulio]

The correct answer is - it depends.

It depends on the type of expander plug that is used. Some, and Cannondale is one example, use a long tight fitting plug that supports the steerer from the compression forces of the stem. In their case the instructions are to cut the steerer 2-3mm below the top of the stem.

If the plug is not doing anything to support the steerer this way, then a small spacer on top can make sense, for reasons already stated.

[Wonderman]

As long as the steerer extends past the top of the stem it should be ok. I assume we are referring to a carbon steerer. If the steerer does not extend past the top of the stem, you are risking cracking the steerer when you tighten up the stem. One of the weight weenie manufacturers, Tune or AX, manufacture a top cap that also acts as a spacer, about 2mm if I remember correctly.

I was under the impression it was the other way around, the steerer should be just below the top line of the stem to allow the top cap to compress properly?

[xena]

Like this.

[glepore]

As long as the steerer extends past the top of the stem it should be ok.

If the steerer extends past the top of the stem, and you don't use a spacer, how do you preload the headset?

[mattr]

You use a spacer.

[Poulidor]

If you don't ask, it would have never occurred to me to leave any space or spacer above the top of the stem. And unless someone convinces me with categorical arguments I never will. I see no reason for it and I think it looks butt ugly. I cut the steering tube flush with the top of the stem and that's it. Never a problem. Am I doing it wrong...???

[mattr]

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.

[Bogan]

Different opinions. Even the manufacturers differ. Enve say leave at least a mil of steerer above, Cervelo below. THM recommend 3mm of steerer above the stem with a 5mm spacer Probably wise to check the manufacturers website.

If the steerer sticks above the stem, how do you preload without a spacer? You can't so, you use a spacer!

[rbrtwyn]

I've been using a 3mm carbon spacer I picked up at vcrc http://www.vcrcbike.com/Carbon_Headset_Spacers_s/99.htm

looks great and barely noticeable.

[Wonderman]

Different opinions. Even the manufacturers differ. Enve say leave at least a mil of steerer above, Cervelo below. THM recommend 3mm of steerer above the stem with a 5mm spacer Probably wise to check the manufacturers website.

If the steerer sticks above the stem, how do you preload without a spacer? You can't so, you use a spacer!

But do enve means to leave a mm of the steerer above and then a spacer? This would result in the steerer being below the who set up as I thought was right?