Welcome to SW forums Sean
Check this thread/post and try to use the suggestions: http://www.eng-tips.com/viewthread.cfm?qid=213311&page=163
Also read this post for your future reference: Forum Posting
After looking at this page and learning a little about BMX with Pro-E
I would say the best is Cosmos and maybe interference checker.
But I would have to say that sadly after reading this article from PTC
solidworks has some catching up to do.
That is some pretty neat functionality in ProE. I am not aware of any way to get that functionality in solidworks currently. For those that don't know, bowling ball cores are actually quite complex. I anticipate the way your friend would like to use it is to define some parameters like radius of gyration, max volume, along with a general shape and have the software do some optimization to get the geometry he is looking for.
With simple shapes, where volumes (and inertia properties) can be calculated in excel, I can imagine the solver funtion in excel would work well. The bowling ball problem would seem a bit trickier.
I am curious what tools Ebonite uses for their designs.
Here is a recent thread by someone from SolidWorks asking the users how they use and would like to use SolidWorks Mass Properties. Your question/request may spark their interest.
I know this is an old post, but has any similar functionality been added to SW? Before we switched to SW I used Creo and Pro/E for about 10 years and this is one of the few things that I miss.