I took Normans advise, I got some heavy duty tubes,set of Michelin Road Rock tires and then wrapped the inside of rim with tape. Put baby powder on inside of tires and rubbed down tubes with powder. Mounted to rims and pressurised ,then let out air and worked valve stem up and down . Then reapplied pressure to 20psi and rolled tire to seat in rim,then pumped it up to 70psi. Also put slime in tubes before final airing. Have had no problems since.Thanks to everyone for the information.