# Carbon Steerer Spacing



## RaiderHater (Aug 15, 2005)

Hi all. I have finally been able to build up my dream bike in the form of a Race with the sloping geometry. I have everything assembled, but just need to cut the carbon steerer tube. Does anyone know what the maximum spacing height between the headset and stem can be. Seems like I have seen 20-30mm but just want to make sure I measure twice before cutting once. Can't wait to join the Merckx brotherhood. Thanks. Dennis


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## atpjunkie (Mar 23, 2002)

*ya might wanna ride it with spacers above the stem*

and move them below, etc..until you find the fit. I'd experiment for a month or so and get the ideal placement before I cut. I've seen 40mm, heck I've seen more. It's a 1.125 steerer and I assume you are not a beast. stack of 20-30 is fine. If ya want less stack you can always flip the stem or get one with les drop, quite common on comapcts these days


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## RaiderHater (Aug 15, 2005)

Thanks atp, good advice. I did cut it little long just in case. Just having trouble getting the plug to stay tight attm.


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## skepticman (Dec 25, 2005)

I didn't know there was a standard until I saw this:

http://www.competitivecyclist.com/za/CCY?PAGE=FAQS#ques_28

"Given that most of the forks we sell have carbon fiber steerer tubes, we are restricted by industry standards to a limited 'stack height' of spacers. We can only stack a steerer tube as high as it is wide. In other words, for a 1" fork, we are permitted to stack the fork with 2.5cm of spacers. For a 1-1/8" fork, we can stack it 3.0cm."


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## atpjunkie (Mar 23, 2002)

*well I always get blasted*

but I just apply simple rules of engineering. Think of this as a lever (actually 2,left and right).
now the wider the bars the more power the lever has. bigger riders means wider bars and more weight so that increases the leverage. Now extend the steer tube. for every bit between the bottom of the stem and top of the headset this is the are getting isolated to side leverage. the longer the difference the greater the leverage forces, yes?
so big rider, wide bars all increases the leverage, now the longer the steerer does the same and all this force is focused on an unsupported structure (steer tube) basically at the headset. 
I get into flame wars with folks who sometimes just won't recognize the very simple forces going on in such situations. Now narrow the steerer to 1", (which makes it weaker) and you've further increased the load at this junction.


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