One arm chin

During the last months I've been working towards performing a full OAC. I've made good progress and I'm at the point where I can pull myself all the way up from an almost extended arm. But if I start in a one-armed hang with a straight arm, I can hardly get anywhere.

How can I strengthen this lower/first part of the ROM? It seems to be the only weak link before i can perform a full one arm chin. I'm thinking about one-armed hangs for time, or short bursts of (unsuccessful but still maybe effective) attempts to get up from a straight arm hang. Would that help, or can you give me other advice?

Work negatives in the 180-150 degree ROM. Go as slow as possible.

The top part develops easily because most of your strength is applied to the top of your ROM so when you get near the bottom you don't get enough practice. Start from 90 degrees and go moderate to the 150 degree elbow then go really slow to 180.

Also, you can work assisted concentrics with a pulley or something else.

Thanks, I'll go for the slow negatives. I'll be back here with results