Wanting to know where the axle centre should be for the sidecar wheel in relation to the rear wheel of motorcycle?

Plus set up of sidecar wheel as per toe-in to bike?

I am only getting 2000 miles from the wheel tread I feel the excessive wear is due to wheel alignment and position of sidecar in relation to the motorcycle.

Thanks for any help
Andrew

It helps if I know which sidecar you have. I run with a Velorex 700 sidecar and the 562 or 565 velorexs would align the same since they all run off the same frame. Misalignment will chew up your tires, your front tire as well as your sidecar tire.
Couple of references for starters..
http://scooter.sidecars.home.comcast.net/alignment.htm
http://www.lap.ttu.ee/xj600/ural/HowToRide.pdf#search='Sidecar%20alignment'