Steerer tube ridge


Was replacing my expander plug on my bike, noticed this vertical ridge running down the steerer tube to below the upper headset bearing. It finishes with a sharp nodule (?excess glue). Used a torque wrench for installing everything.

I’ve attached an image of said steerer

Thanks in advance

Looks like a seam where the carbon sheets met. It’s not very well made but I wouldn’t worry about it if the stem slips on normally and there are no cracks or voids. What brand is that?

(FWIW, torque values are usually stated as a “maximum”. That means you use the minimum necessary force to tighten the stem and not go straight for max.)

AND be very careful! I had one bike that showed torque values for a STANDARD stem, not one on a carbon fork. Using standard torque would have destroyed the top of the steer tube. Expensive…

That looks like bad manufacturing. I don’t think you could crimp carbon like that, once the resin has set. If you can, I’d enquire with the manufacturer.

Looks like a Pinarello (or maybe a fake).

Tubes usually don’t have butted layers of carbon. I’m guessing it’s just excess resin pushed out where the vacuum bag sides came together, then poorly finished afterwards.

I’d just sand off the ridge if you are out of warranty.