Hello i have a folding bike from the 80's with small 14" Kenda tires on the original steel rims. The bike is a Bridgestone Picnica. These tires also say on the sidewall that the minimum tire pressure is 40 psi and maximum psi is 65 psi. I have 30 psi in my tires at the moment just because i'm afraid that my rims cant handle so much as 40 psi. Do you think that they can handle higher air pressure without any problems?