I have a question about tires,I bought my 84 R 65 they put new tires on the bike when I bought it..They are 2 different tires,Continental on front, Kenda on the rear.What is the best tire to use on these bikes ? I find the rear tire ( Kenda ) looses air pressure.It is also hard to put air in due to the location of the valve stem.Any suggestions on what is a good tire for my bike .Since I have the bike running good now,I may invest in a good set of matching tires,hopefully they will be easier to put a tire gauge on and air in.PS : also a good price to.Thanks for the help.