# How much fork steerer tube to cut?



## PixelPaul (Oct 8, 2004)

I'm bringing my bike to the shop tommorrow to have built up, and wondering if there is a rule of thumb on how much of the fork steerer tube to have cut? It is a new frame and fork and the tube in ginormous, extending 6" over the head tube. I don't currently have a road bike to reference. Is there a "standard" amount or formula, I'm thinking maybe 2-3 spacers worth? Maybe the shop will know this and just cut based upon the frame size? Am I over thinking this?


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## Jay Strongbow (May 8, 2010)

No, you're underthinking it. You need to cut the fork so the bike fits and that needs to be done within the parameters of the fork makers specifications for how many spacers you should have over and under the stem.


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## laffeaux (Dec 12, 2001)

Until the frame is built into a bike, don't cut the steer tube.

The steerer tube needs to be long enough to place the handlebar at the height that is proper for you. Your choice of stem, your height, your flexibility, your preference, and the head tube length all determine where the handlebar should be (and therefore how long the steerer tube needs to be). Build the bike completely to check fit before you cut.

Once you decide to cut the fork, I generally leave a little extra tube above the stem (more than is required) to allow for adjustments in the future.


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## c_h_i_n_a_m_a_n (Mar 3, 2012)

When I built my bike, I went with the max spacer allowable for the fork, under the stem, plus 5-8mm above the stem. I know I should not need to leave the additional length above, but, there you go. So now I have a 7mm spacer on top.

Initially I was riding with the stem tilted up, but then I tilt it down, but have so far kept the stem height where it was.

Eg: http://www.eastoncycling.com/bike/wp-content/uploads/2010/04/fork_ITT-EN.pdf


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## logbiter (Sep 14, 2005)

The headset & stem will take up 2-3" of that. Leave 20-30mm worth of extra to account for spacers (to dial in your fit) & a different stem. Stems & headsets have different stack heights, so you want room to work with if you change those down the road. You can always cut it down more, once you have your ride dialed, if the spacers bother you.


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## JCavilia (Sep 12, 2005)

It was so much simpler with quill stems and threaded headsets.


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## jsedlak (Jun 17, 2008)

I don't understand the point of having so much tube if the manufacturers specify a maximum number of spacers...

I vote for cutting it for the max w/ stem and then get fit on the bike.


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## Jay Strongbow (May 8, 2010)

jsedlak said:


> I don't understand the point of having so much tube if the manufacturers specify a maximum number of spacers...


Hint: Not all headtubes are the same length.


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## laffeaux (Dec 12, 2001)

jsedlak said:


> I don't understand the point of having so much tube if the manufacturers specify a maximum number of spacers...
> 
> I vote for cutting it for the max w/ stem and then get fit on the bike.


Also, forks can be moved to a new frame in the future. Or sold. If you replace a frame having the extra steerer tube helps ensure that you can use the fork in the future.


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## cxwrench (Nov 9, 2004)

jsedlak said:


> I don't understand the point of having so much tube if the manufacturers specify a maximum number of spacers...
> 
> I vote for cutting it for the max w/ stem and then get fit on the bike.


as others have posted, there are different lengths of head tube depending on bike size, sooooo...:idea:

i do agree w/ putting the max amount of spacers under the stem and cutting IF you haven't had a fitting done and don't know exactly where you'll end up. this way you're as high as you can go, and can always cut.


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## Roland44 (Mar 21, 2013)

Jay Strongbow said:


> No, you're underthinking it. You need to cut the fork so the bike fits and that needs to be done within the parameters of the fork makers specifications for how many spacers you should have over and under the stem.


Exactly this! That's what I did at least and worked fine...


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