I have a 2007 Street Bob with spoke rims. I think the stock front tire is 100/90 R 19 and I have 18000 miles on the original tire. My question is what is the next largest tire and can It be installed and perform safely without excessive wear of safety hazard.

 

A 110 would be no problem, not sure what your rim width is, but a 120 should not be an issue either. I have a 110x19 on my WG and really like the way it handles.

 

+1 a 110/90 is no problem. Also a 120/70 (vrod tire) is cool too - Cant go larger than either of these though