Can you Cut Only 5mm from Carbon Steerer Tube Without Cracking/Splintering?

Before any of you worry too much, I haven’t ruined a bike frame or anything…yet. :roll_eyes: I have all the right tools (Park Tool saw guide & carbon-specific hack saw blade, etc.).

I’m a “tester” by nature, so out of an abundance of caution I cut about 1cm-1.5cm less than I ultimately needed to off of my new carbon fork as I prepare for a build. Even using the right tools, but forgetting to tape completely over the cut area, I got a bit of splintering that resulted in a slightly uneven cut. Even though I left 1-1.5cm extra, again out of an abundance of caution, I’m considering cutting only 5mm off the tube this next go around, to allow myself room for error in case something goes wrong. However, this got me wondering if only 5mm can be cut off of a carbon steerer fork safely, or if I will just be asking for splintering or cracking again with that small of a cut??

Does anyone have any experience in this realm, and should I just go ahead and cut at least 1cm off, instead of trying for only 5mm?


I’ve cut ~3mm off a carbon steerer (Giant bike), with no observed delamination or other ill effects.

I use an old stem as a guide when cutting carbon steerers, along with a fine toothed metal hacksaw blade.

I cut halfway through from one side, then finish the cut from the opposite side.

Wrap some masking tape around to help prevent any splintering and use a sharp fine toothed blade (as mentioned above).

My Dad used to always say “let the saw do the work”. take your time, don’t apply too much pressure you’ll be fine.

yeah, no problem. The guide has that long clamp for that purpose. The carbon cuts cleanly. The blade is thicker than you might be used to, so keep that in mind when you mark your target. You’ll also want to sand/file down the finished cut a bit.

While you’re in there, make sure you have a real long compression plug

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