Riders Insurance offers towing with their insurance package. I've had Riders for 4 years and w/20k miles of riding, I've never had resaon to 'test' their service. Th offering is bascially the same as HOG and I believe they provide towing assistance on all your vehicles. They do only service a half dozen states. Cost appears to be reasonable. They were less expensive then Progressive, which I have 4 vehicles with.
www.rider.com

 

It's still a good deal if you have AT&T you get an additional 18% off your monthly bill. It saves me about $220 a year so the annual membership fee is a no brainer. I still save a bunch and get at least 1 tow if I need it.