[chrisguyw]

The  standard   brush   gear   is  a  heavy  brass coloured  contact and  when I  powered  it  up   on 12v    as  Anthony  says  they  scream   my  test   on SF  results    clocked  225550 rpm  before  I  shut  it  down .Shades  of  strap motor  lol. I  did get  a  puff  of  smoke   before   I  killed  the  power   but  no  damage .

Wow, 225K...........my hand built Koford $450US Eurosport motors struggle to do much more than that.................with a cold steel armature shaft, a non balanced/non epoxied and unground arm, cheap bushings, a plastic non tied non epoxied untrue comm, topped off with the cheapest brush gear that the Chinese toy car motor manufacturers offer,....you are a lucky man 

Not that I do not believe you , but , in my opinion, you motor would have disintegrated well (well) before 100K. 

Cheers
Chris Walker