I'm currently encountering a weird discrepancy between the force I can generate to lift my body with one arm and the amount of weight I can pull down with one arm at the lat machine, using a one-handed handle.
At this machine I can only pull 60kg (132lbs) twice, as compared to lifting my 86kg (190lbs) bodyweight two thirds of the way.
Many people report they only have to lift 65-75% of additional bodyweight on weighted pullups to manage an OAC. This makes sense because your body is in a more efficient pulling position for the OAC, thus utilizing more muscles and furthermore less muscles are pulling in contradicting directions, thus fewer forces are canceling themselves out.
However, this does not apply for the OAC vs. One arm lat pull (OLP). Can friction of the machine play such a big role? It has a 1-to-1 transmission, and only one big wheel to direct the rope. My knees press against some stabilizer, may this cause my body to tilt less, and therefore utilize less muscles?
My general question is, where does this discrepancy originate from?