Bicycle Mechanics - Shortening a quill stem (expander cone type)

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CabezaShok
05-21-11, 09:10 AM
Hi im wondering if its possible to shorten/cut a quill stem that uses an expander cone at the bottom. i know its possible with the wedge type quill but im not sure about an expander type....i never saw one in person. Theres a stem on Ebay i really like but the seller only says "you can put your handlebars 15cm above your headset"
He does not mention insertion length: http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=330362214925&ssPageName=STRK:MEWAX:IT#ht_500wt_922
Cheers!
fietsbob
05-21-11, 10:45 AM
If you need a shorter stem, simple.. don't buy that one ..
though it appears a steel tube with an aluminum head.
So you should not need to re machine a cone taper
Like, inside a thick wall aluminum quill stem..
will only be an issue on a fork with a very short fork steerer
then often the bike is for a straight/flat bar and the stem
height is welcome.
Pink on the head?
Shortening a steel stem with a cone expander is very simple. In fact it's easier than with a wedge type because there's no need to match an angle.
The only limitation is the thread length of the expander bolt.
However like the prior poster, your best bet is not to buy something with the intention of modifying it, There are many stems available and you should keep looking until you find that's fine as it is.
Anthropy
05-21-11, 03:48 PM
I would disagree that shortening a cone is easier than a wedge. The recess on my Schwinn cone types have the inside reamed out at a taper. So you have to cut to length, ream, and cut the 2 relief slits on either side of stem. Whereas all you have to do with a wedge is to match the angle and make the cut and clean up with a file.
But the previous posters are correct. Buy something the right length to begin with. You will loose about 2 1/2 to 3" off of the length for minimum insertion, so you can subtract that length from the stems you are looking at.
Tom
I would disagree that shortening a cone is easier than a wedge. The recess on my Schwinn cone types have the inside reamed out at a taper.
Your conic wedge stems are probably aluminum. My post referenced a steel stem, which is what the OP has (steel column with alloy head). Steel stems don't have a conical inside, you only need to deburr the cut.
CabezaShok
05-21-11, 04:43 PM
Awesome advice...thanks!
Anthropy
05-21-11, 06:49 PM
Yes, they are both aluminum. Nice info to have regarding the wedge steel. Thanks,
Tom
urbanknight
05-21-11, 07:53 PM
Your conic wedge stems are probably aluminum. My post referenced a steel stem, which is what the OP has (steel column with alloy head). Steel stems don't have a conical inside, you only need to deburr the cut.
Wouldn't you still need a slit up each side? Steel or aluminum, I've never seen one without slits cut up each side to allow expansion.
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