Heavy-weight Clamp with Thorens idler-drive

I recently purchased a Thorens TD124 in a Bastin plinth. I have been using a TTW 2.8 lb. record weight. There are sonic benefits when the clamp is in place, but the platter takes longer to come up to full speed. Does this mean that the belt is slipping, or would this be considered normal when using such a heavy clamp? Also, is there any way, with this particular table, that I am placing undue wear/stress on the bearing and motor?
I've been wondering the same thing with my Garrard 401. I also have a TTW copper mat, which adds another pound or two.

I don't notice any difference in start up speed, it's up to speed in about 1/2 evolution. I haven't gotten around to checking bearing wear yet, I've been meaning to, so I'm planning on it in the near future.

No signs of any trouble yet, though.