I bought an Origin 8 threaded to threadless adapter, as seen here: https://www.amazon.com/gp/product/B0037N6PEC
The stem I have is: https://www.orbeaproshop.com/products...=18&product=63
I'm having issues with the stem rotating on the adapter.

Since the stem is carbon, I don't want to just crank down and over-tighten, so was wondering if any anyone had advice on how to roughen up the aluminum (just sandpaper?) or any other advice on how to give these components some traction. Thanks!

zmensing: Use Tacx, Fiber Grip or FSA Carbon Assembly Paste. A Web search will turn up numerous vendors.

+1 And find out what the proper torque is for the stem bolts and use a torque wrench to get it right.

Sorry if this is off topic, but zmensing, can you post a picture of your stem adapter on your bike and how it looks lowered all the way? I just picked up a Dimension stem adapter and it doesn't seat all the way down because it's too long I think. So I'm looking for other alternatives.

And how heavy is yours?

Thanks!

The nitto is the best option IMO, is heavy tho. But wont bend and is knurled in the stem area too, so the stem wont slip at all.


U have 2 versions...




And the MTC-12 that is almost the same as the above but has a top cap that is threaded and the neck is longer so yo u can play with the stem better than with the other one.



I have a MTC-12 and the thing is way better than other stuff moving around, the nice about it is that U just put it all the way down and neck gets integrated with the headset and basically stiffing the front of the bike a lot.

FWIW, knurling is like a knobby tire, in that the tips are all that will be in contact,
Unless the material of the stem is softer than aluminum.

Have carbon and aluminum stems and never got the problem the OP is claiming, not even with this adapter thats why I adviced about them.

Thanks for all the advice. I'll try to get a picture of the stem adapter all the way down, for now I only have one with it raised up.