Back Collapsing at Bottom of Clean

I’m not really sure why this is happening, nor how to fix it but when I hit the bottom position of a heavy clean my back collapses and I dump the weight. Any help would be greatly appreciated.
The video is of 120kg.

Does this start happening at a specific weight? Does it always happen at that weight?

At 100 and 110 it sometimes happens, I can usually rack those accurately enough that it doesn’t but when it does they’re light enough to muscle through, every time I attempt 120 it crashes into the rack position and I dump it forward.

I can’t personally tell from the video, but it sounds like the bar is crashing down on you. This means you’re not meeting the bar which could be because of a few things. Could be that the bar is too far away from you so you have to pull it back in and so it crashes.

However, that’s just what it sounds like to me, I can’t tell from the video.

In your starting position, your upper back looks just a little rounded (at least as far as can be told from the video clip). Not sure if that’s translating through to the bar being forward of your center of gravity, but if it is that might be setting you up for loss of the bar at/after the catch.

Upper back looks rounded at start, but the main reason is because you’re not getting your elbows around fast enough and the bar is too far away from you when you pull under. Work on keeping the bar closer. It also looks like you cut your extension in the second pull. This helps to bring the bar back/keep it closer.

Thanks for the help, I actually managed to hit it today, felt like I was able to keep my back tight from the start and it came into the rack secured, ended up being an easy squat out of the hole from there.

Thanks for the help, I actually managed to hit it today, felt like I was able to keep my back tight from the start and it came into the rack secured, ended up being an easy squat out of the hole from there.

Can you do a full snatch? I have the same problem and I know it is due to poor flexibility in one of the following, hips, ankles, or thoracic spine (or all 3). It can also be due to weakness in the back or core, but if you an front squat that weight or more with a relatively straight back then it could be a technique issue where the bar is drifting out too far in front of you and as a result it is landing too far forward on your delts.

I can’t full snatch properly, i believe it’s my thoracic/ shoulder mobility as I cant catch it far enough back to be secure at the bottom, best snatch being 80 kg. I can front squat 315x3 fast with an upright back (335x3 if I use a belt which I haven’t done since my last powerlifting meet in August).