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Discussion Starter · #1 ·
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So I've slowly gotten into a more aero position on the bike: flipped the stem, then one at a time moved the 4 spacers from below to above the stem. Now I've got 4 spacers stacked on top of my stem and I'm guessing this is not accepted practice and may also be a health risk?

So next step then would be to trim the steerer tube? I've got a carbon fork but the steerer tube where the spacers are stacked is metal. Anyone else have a similar experience or suggest a procedure they used?

Thanks!!!!
 

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Converted Runner
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Park Tool suggests using a 32 TPI hacksaw (that's 32 teeth per inch) and a good clamp/guide. I can't find the full article dedicated to the steer tube, but they say just use a fine tooth hacksaw here.

That being said, and this is coming from a mechanically inclined person who usually does all their own bike maintenance, I would probably take it to a shop that way the liability is somewhere else if something goes wrong.
 

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RoadBikeRider
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Measure twice...or three times. Measure again. Mark it with tape and cut it. File the end flat and smooth with a fine file. Pretty easy task but take your time, you only get one chance to not cut it too short.
 

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Don't forget to install a new star nut as the old one will probably be in the part you cut off.
 

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Discussion Starter · #7 ·
frdfandc: that's what I was wondering about. It looks like if I trim the steerer, I'll lose the threaded entry (star nut, thanks) for the stem bolt. I'll have to see what's involved in installing a new star nut.
aengbretson et al.: thanks for the Park site link. IF I decide to cut it myself, my first instinct was to measure and mark with tape, remove the stem, and then make the cut in place. If it's gonna be a tricky procedure to pull off, I have no probs with taking it to the LBS.

Am I right in thinking that riding around with 4 spacers stacked on top of the stem is a big NO-NO? Is it something that a race marshall could call you out on? (i'm new here :) )
 

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You can pick up a steer tube cutting guide tool from Performance for under $15.00, I think it's the Spin Doctor brand. Had mine for 4 years a lot of my riding friends borrow it when they building up a new bike. Good luck
 

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bruce_wayne said:
Am I right in thinking that riding around with 4 spacers stacked on top of the stem is a big NO-NO? Is it something that a race marshall could call you out on? (i'm new here :) )
What size spacers? If they are 4 at 5mm each, I wouldn't worry about it but if it was 4 at 10mm I would. I cut my carbon steerer tube using the Performance guide and a fine tooth hacksaw, and it was a pretty straightforward process. Since it was carbon I wore a mask and cleaned up carefully - not such a concern with Al but still I wouldn't want to breath metal filings in. I don't know about the threading though.
 

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Sounds like you are cutting an aluminum steerer. If so, measure multiple times as posted above, drive the star nut below the anticipated cut and use a pipe cutter suitable for copper pipe. If you haven't used a pipe cutter before you can practice on some aluminum electrical conduit. Remove any burrs and file it smooth. Be sure to use minimal pressure so as not to "egg" the steerer. Search "cut steerer pipe cutter" to find more detailed directions.
 

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Cycling induced anoesis
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bruce_wayne said:
frdfandc: that's what I was wondering about. It looks like if I trim the steerer, I'll lose the threaded entry (star nut, thanks) for the stem bolt. I'll have to see what's involved in installing a new star nut.
aengbretson et al.: thanks for the Park site link. IF I decide to cut it myself, my first instinct was to measure and mark with tape, remove the stem, and then make the cut in place. If it's gonna be a tricky procedure to pull off, I have no probs with taking it to the LBS.

Am I right in thinking that riding around with 4 spacers stacked on top of the stem is a big NO-NO? Is it something that a race marshall could call you out on? (i'm new here :) )
Tape will work ok, but I would remove the fork to make the cut. You don't want metal filings getting into the headset, plus making the cut with the fork installed would be combersome, IMO.

You can still use the installed star nut, just relocate it below where the cut will be.

The majority of the stress to the steerer tube occurs between the top of headset and stem, so (aesthetics aside) the spacers above it aren't cause for concern.
 

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I had my steer tube cut by the LBS. They cut it while I waited. Ten minutes, ten dollars, no mess, no worries, no extra tools I will only use once.
 

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no measure

andulong said:
Measure twice...or three times. Measure again. Mark it with tape and cut it. File the end flat and smooth with a fine file. Pretty easy task but take your time, you only get one chance to not cut it too short.
Forget measuring. Assemble everything the way you want it, remove the top cap, then mark it with a felt pen. Then, remove and cut just below the mark.

I measured a Colnago C40 Star Carbon fork and transposed numbers, then cut too short. $850 mistake. I always mark now. With marking, no need to measure.
 

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Discussion Starter · #15 ·
Thanks, all.
Have plenty of experience using a pipe cutter on copper tubing for plumbing repairs so I like this option. Drawing a line around the top spacer and then cutting a little below the line seems like a good way to measure for the cut.

Still not 100% sure on the positioning of the star nut (haven't had a chance to remove the stem bolt and take a look) but if I understand you guys correctly the star nut is encased in a disk which fits snug inside the steerer tube. I ought to be able to lightly tap this disk down below the cut line before making the cut?

PJ, if 4 spacers on top of the stem is mainly a question of aesthetics/appearance, then I'm in no big hurry to trim the steerer. Finally, if my LBS can do it on the spot for $10-$20, that's an easy way to take the guess work out of everything.

I'll let you know how things work out. You guys are the best!...
 

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I'd leave at least one spacer above the stem, makes it easier to tighten up the steerer and stem, gives you room to go back up if you decide too.
 

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bruce_wayne said:
Thanks, all.
Have plenty of experience using a pipe cutter on copper tubing for plumbing repairs so I like this option. Drawing a line around the top spacer and then cutting a little below the line seems like a good way to measure for the cut.

Still not 100% sure on the positioning of the star nut (haven't had a chance to remove the stem bolt and take a look) but if I understand you guys correctly the star nut is encased in a disk which fits snug inside the steerer tube. I ought to be able to lightly tap this disk down below the cut line before making the cut?

PJ, if 4 spacers on top of the stem is mainly a question of aesthetics/appearance, then I'm in no big hurry to trim the steerer. Finally, if my LBS can do it on the spot for $10-$20, that's an easy way to take the guess work out of everything.

I'll let you know how things work out. You guys are the best!...
Yes, from a safety standpoint, you're fine running that setup 'as is'.

Here's a pic of a star nut:
View attachment 207730

... and what you're apt to find when you remove the top cap:
View attachment 207731
 

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Peanya said:
I'd leave at least one spacer above the stem, makes it easier to tighten up the steerer and stem, gives you room to go back up if you decide too.
QFE - about 3mm above the stem is recommended, that way you can put a 5mm spacer above the stem and have plenty of room to tighten it down.

On the "assembling everything and marking it" deal (I think this is the best method... fewer ways you can mess up) - make sure that everything is pressed together tightly. Some forks, spacers, headsets, etc. don't sit right on each other, so you can end up with your steerer being longer than intended and you have to cut again. Obviously removing to little is much better than removing too much, but the more times you cut the more chances to F it up :D
 

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Caution

bruce_wayne said:
Have plenty of experience using a pipe cutter on copper tubing for plumbing repairs so I like this option.
If that steerer tube is heat treated aluminum, then a tubing cutter might not be a great idea as the metal can be realtively brittle.
 

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You may also want to think down the road if you plan to sell the bike- it may not be so appealing to buyers if you've cut the steerer for an aggressive drop and there's no room to raise the stem again. As mentioned, extra spacers on top may not look euro-cool, but there's not big harm in it.
 
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