RMoudatir

I had gotten a frame set off Otso last December that included a Lithic Hiili fork, I just started building it recently. I cut the fork with a 32 tpi hacksaw and it cut cleanly. After I installed the fork and stem and tighten the pinch bolts to 6 nm , I found that I needed to cut a few millimeter lower so I removed the fork and upon inspection I find this long line that curves slightly going from the top to bottom of the steerer tube. I find that the piece that was cut off earlier had the identical matching line when I stacked it back on top. The thing is hat I don't even feel anything on it, it is smooth to the touch and inside the tube there is nothing abnormally visible. I hadn't even completed my bike build and now it's cracked? I thought carbon fiber wasn't that fragile if taken care of.

AnkleWork

Not sure what you really want. If you really want to know if it's a crack you could examine the steerer closely, maybe non-destructively test it, maybe destructively test the piece you cut off. If you really want to know if it's a manufacturing artifact maybe ask the people who made it. Nobody in this forum knows. Or is this just an ego thread?

RMoudatir

Ego thread? I just noticed this thing on the fork and I'm sure there are many people with good knowledge about these things here, I am just a noob who has no experience with carbon steering tubes and have heard a lot of warnings about them with over tightening them and having it stacked wrongly.

dsaul

Looks fine to me. That just looks like a line from the overlapping carbon fiber cloth.

bakerjw

As mentioned, contact the manufacturer if you know who it is. That is one bad thing about chicom carbon. There is no accountability on their end.

Take the piece that you cut off and lightly sand it and then get it wet to see what the underlying weave looks like. You can also take the cut off piece and work it with some pliers in a vise to see if it delaminates near the crack.

It looks like a manufacturing artifact to me. BUT... I am not a qualified expert.

easyupbug 

A steerer failure of some kind is not a risk I would take as I think the consequences could be very serious. There should be a carbon "shop" that builds/repairs carbon not too far from Carona that could render an opinion upon inspection, too difficult from that photo. Properly fabricated carbon is not fragile when used as intended but the strength is directional and is very unforgiving with point loading.

leob1

It looks like the overlap or seam of the carbon cloth, the manufacturer won't spend time and money polishing the steerer tube that won't be seen. It saves them a few pennies per fork.
If it really bothers you, take it to a few shops and ask them to have a look at it and render an opinion. Don't forget to buy something and/or tip the wrench.

zacster

That could just be a surface scratch from insertion.

2old

Appears cosmetic especially if the clear coat isn't affected. However, considering the ramifications, I wouldn't proceed without consulting Otso, the fork manufacturer or sending it for analysis by an expert like Craig Calafee.