Hi, Greg and all,
I have been experimenting "WD-40" which has solvent but also has silicone rubber in it.
It forms some kind of coating after drying, and protect rubber materials from UV ray and oxgen. As far as bike parts, I have 2 to 3 years of records, but I have 1985 Toyota Van with 135K, I kept spraying on all rubber hoses and suspention bushings, 16+ years later everthing is still original.
I have been spraying some tubuler tires and brake hoods past two yeras, and I will tell you what happens 10 years from now.
KEN TODA, High Point, NC, finally, our air feels a bit dryer!