That’s a HED disc, isn’t it? I don’t think that’s a cassette, I think it’s one of those Chinese 9-speed screw on mega freewheels. If you slip that aluminium axle off, I think there might be splines down the bore. It might be smaller than the usual Shimano one though.
Park Tool FR-1 has 12 splines and is approx 22.5mm diameter across the outside of the splines. Shimano one looks like it’s closer to 23.5mm diameter but I haven’t got a calliper to accurately check.
That’s a HED disc, isn’t it? I don’t think that’s a cassette, I think it’s one of those Chinese 9-speed screw on mega freewheels. If you slip that aluminium axle off, I think there might be splines down the bore. It might be smaller than the usual Shimano one though.
Weld it up and chainwhip, if in doubt!