If I remember correctly some years ago an article was done somewhere giving the details on how to modify the Bachmann two truck trolley car to allow it to traverse down to a 9 inch radius curve. I am looking to find out how to do this for a model that is being built. Can anyone here provide any insight or information on how to do this?
See this site
http://www.nwsl.com/Catalog/CatalogSect4.htm
Remove the old motor drive that fits through the floor, patch the floor, then use two of the four wheel drive units sold by NWSL.
Have fun