I have a DM, I recently started using thin (gray) shims and 100% polyester strings. since this two changes my throw is crooked 90% of the time, what makes the string rub against the starbursts or the o-ring. Right now the strings are breaking at a rate of more than one a day (depending on use). another thing I noticed is that when the string rubs against the o-ring, the o-ring leaves a black mark on the string loop. Is this ok ? cause this is the only reason I can think of, do you have any other suggestions ?
Thanks in advance