I've asked the girls who've been working at the counter the last 3 times I was in and none of them have a clue. I also wrote a note and left my number so someone could call me. This is a good gym actually but I think a lot of them are on holiday this week so they've left the bimbos in charge. I also asked a couple of experienced guys there too but they could only tell me that the plates weigh 15 lbs each.