Trackball replacement for Kensington

[Subdromat]

Iam using a Kensington Trackball with 55mm ball. I tried to replace it with a polished stone ball and it doesnt work. Unfortunatly the stone ball is too heavy ( stoneball is apr. 250g  , stock ball is about 100g) and it will persumly damage the ceramic guideway of the trackball.
 My question is:  Is there a way to interchange the original trackball and what kind (material) of ball should be work without damaging the trackball

tx

[noisyturtle]

A billiards ball should work perfect

[kabbabu7]

I recently reached out to Kensington support, asking if I could purchase a replacement ball for my Expert Wireless. They asked for my address and sent me a dark coloured ball, I believe the one from the wired version. Might be worth getting in touch, like I did.