I would suggest calling Ron at IVO Propellers. I would also like to comment on the super customer service I received at IVO. I recently purchased an IVO IFA for my Vixen and when it arrived there was a slight dent in the spinner. I advised Ron and also mentioned that the brushes seemed to be wearing quite rapidly. He suggested the first set wears faster until the hub "carbons up'.
Just today I received a replacement spinner and 2 sets of brushes-- All at no charge with mail directly to Canada. Now that is what I call customer service. I think in this day and age service like that should be rewarded. I hope I am not out of line by mentioning it here.
Cheers
Don (New IVO supporter).