| WD-40 is composed of 80% Stoddard Solvent (that is similar to paraffin) and 20% light lubricating oil. It's the light oil part that you have to be careful of (slippery.) Just wash it off with detergent.
The other slippery substance that you really want to avoid getting on your tyres is silicone oil contained in Armor All and other rubber dressings. Particularly on stored vintage bikes.
There are two main degrading agents that attack tyres and rubber parts. They are UV light waves and ozone. Both of these attack the long hydrocarbon chains of the rubber and by breaking these chemical bonds, shorten the molecules with resulting loss of elasticity and other problems.
Tyre manufacturers add two primary sacrificial protectants to the rubber. To protect against UV, they add carbon black. This is why tyres don't come in designer colors to match your paint. The carbon black will turn white/gray as it absorbs the UV and dissipates the energy as heat. Thus the basis of rubber parts turning gray as they age.
To protect against ozone, tyre manufacturers add a wax-based sacrificial protectant. The ozone attacks the wax and depletes it. As the tyre rolls, additional wax is forced to the surface of the tyre. This is referred to as "blooming". This blooming refreshes the surface wax protectant. A tyre that has not been flexed will have the wax depleted by the ozone and thus begin to degrade and suffer "dry rot".
The silicone oil in Armor All and similar products actually dissolve the wax and be the cause of premature tyre side wall cracking/failure. It is rumored that some tyre manufacturers will not honor warranties on failures caused by silicone-based products. A tyre dressing should contain a UV protectant to bolster the efforts of the carbon black and preferably not contain any silicone. Read the label.  |