Renthal Apex Stem 40mm Clamp 31.8mm +/-6 Degree 1 1/8 in Black/Gold Aluminum MTB

Trail;

Es la segunda potencia que uso la anterior es más larga y simplemente quise probar una más corta esta marca vale cada centavo que pagas 100% de satisfacción!!!;

Love the upgrade. 40mm stem with 20mm rise bars on my stumpy felt natural;

I am not sure if this is more of a review or a fact finding mission but I upgraded my stock stem on my eMTB to this stem as I have frequently used Renthal (and Protaper) on my motorcycles. So I purchased the Protaper carbon fiber bars and paired them with this Renthal apex stem in 65mm. I used carbon grease to secure the bars (Finish Line Fiber Grip Carbon Fiber Bicycle Assembly Gel) and a torque wrench to properly secure the bolts to spec but my bars would always end up rotating back into my lap over time. Over time means over the course of 7-10 rides. So I would have to readjust the bars and retorque to spec. Now I WANTED to overtorque the bolts in order to prevent this slow movement over time but am not interested in damaging my carbon fiber bars...
To get to the point on a ride back in June I dropped about 24-36" on a single track and my bars completely rotated down. Next thing I know I am landing on my head with my bike 10 yards down the hill. Thought that I broke my collarbone but apparently suffered a SternoClavicular sprain (didn't even know that existed) that I still feel 4 months later.
So I am not sure if carbon bars just are not meant for that type of aggressive riding (which I would not have considered that aggressive until after the get-off) or if both my torque wrenches are that far out of calibration or what. But I have since removed my CF bars and installed some PNW aluminum bars for piece of mind. Yet the bars appear to still slowly shift backwards (rotate) over time like the CF bars and these are certainly cranked down more than the CF bars were. So I am wonder if it might be the stem?
My original stem never allowed the original bars to budge...but in my quest to upgrade the bike it seems that I might have made a bad choice in this stem? Or I seriously do not know how to set up this particular stem. I will say that I DO NOT like that installing bars with this stem are so difficult seeing as you have to slide them over from a smaller OD part of the bar with resistance as you get to the mounting area...I feel that this is what is causing my issues and perhaps the design needs rethinking? I will say that the bar and stem combo are great for weight watching though and the comfort from the Protaper bars is missed right now...;

Looks great and was easy to swap from original part.;