well for me, they seems to work best on echo urban rim straight after grinding...althought i have try all hole now, and they didnt work best on new hard grin ( ? ) but when i fithed them on dead grind on the same rim they works perfect ( that is weird). my advice would be to leave them to bed in better maybe and you will see. in my opinion, that pads in alu backings are worth of waithing to bed in
i hope they will work