It helps to lubricate the line with saliva before you try and slide the string stopper.
I also use Stan's bobbers and always had the problem of groves in the bottom of the bobber. I got the idea of using a rivet about 10 years ago. Now my bobbers last forever. I was surprised to see Stans are now putting something similar in the bottom of there bobbers. Haven't had the need to buy one yet because mine last forever.
I have never had a problem with groves in the bottom of the bobber ever. Just lucky I guess. Don't see how you could get that problem??? Maybe you are catching bigger fish.
that happens when you fish 5 days a week. lol
So which style of stans does everyone use ? I prefer the cigar style . I haven't seen the new style with the steel removable insert , do all the styles now have it ? I have used these for a long time and they last long time as Princecraft said .