Follow-Up:
I experienced tread separation on my Contrans tires at 20k miles, and they were replaced under warranty by Continental with their newer Vanco tires. The Vancos are much better tires than the Contrans, and offer the appropriate load rating for the heavy Rialta. You won't find another make/model of tire that will work on the Rialta. The Contrans/Vanco tires are actually a the European equivilent of US load range D. Other manufacturers just don't make 15" tires with this load range. Contact Continental about getting reimbursed for replacement tires under warranty. The tires that are currently on your Rialta probably won't last and are probably dangerous to use them for long distances or highway speeds. Continental is supposed to FEDEX tires to the Continental dealer nearest to you if you are stranded on the road. Their number is the equivilent numbers of 800-TIRE-FIX. When my were replaced under warranty, they were prorated. I ended up paying about $40 a tire, which included mounting, balancing, etc. Not too bad, and I feel a LOT more confident driving with the Vancos than I do with the Contrans. The Vanco tread pattern and sidewall at least have the same look as the specially designed RV tires for the big Class A coaches. Chris www.MotorHomepage.com 2000 Rialta QD
Here is a link that might be useful: MotorHomepage's Rialta Resource