Hi George
I recently bought Diamond Back white walls for my 230SL based on their claim (and lots of positive feedback), that their whitewall tyres don't turn yellow. Apparently most whitewalls eventually turn yellow because the chemicals from the black rubber eventually leach into the whitewall rubber. Then, over time, those chemicals will bleed right through to the surface of the softer white rubber, where light and air turn them yellow over their entire surface. Diamondback tyres claim to use a unique white rubber formula and their whitewall material is made up of three layers
They state that "the bottom layer is black rubber for maximum adhesion to the tire’s sidewall. It’s the exact same rubber formulation they use to make truck retreads — very strong stuff. That’s because “like materials” bond best. In the middle is a special butyl barrier layer. The butyl layer blocks the staining chemicals that will try to come through from the back. Nothing can pass through this layer. The white “face” layer itself is made up of my own white rubber formula. This is why Diamond Back claims its whitewalls are whiter, and that they will also stay whiter"
As for cleaning, this is what they state :
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CLEANING TIPS (No Bleach)
One of the first things you will notice is that Diamond Back Classics are extremely easy to clean. Most whitewalls turn dingy or yellow because of the leaching of chemicals (mostly anti-oxidants) into the white material. Because our process uses a butyl lining to stop chemical leeching, you only have to clean the surface dirt. We recommend frequent cleanings with an abrasive cleaning pad. A fine or medium sanding sponge works well. These are available at most hardware stores.
Any good cleaner works OK - Castrol Super Clean, 409, Simple Green, Greased Lightning - just to name a few. Avoid cleaners that contain bleach. Prolonged use of these cleaners can “dry” the whitewall surface. Do not use products such as Armor All on whitewall. This could cause slight discoloration. Whitewall surfaces tend to “dry” with time, heat, ozone, etc. A vigorous cleaning periodically will get rid of the dry surface and help maintain the tire’s beauty. Don’t be afraid to scrub.
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As I've mentioned, I purchased a set of 205/70/14 Diamond backs with a 1" wide whitewall for my 230SL. The tyres are are manufactured by Cooper Tyres in the USA. I got a lot of positive feedback from various owners and forums before taking the plunge.
Rgds
Frank
