IMHO - "Tire Cupping" of motorcycle and scooter tires is THE most entertaining subject of two wheel riding discussion. (even better than the "synthetic oil", or "break-in" discussions!!)
Veteran riders, shade tree mechanics, young, old, dealer mechanics....
everyone knows what causes tire cupping on motorcycles and scooters.
Cupping is caused by :
Normal Tires cup & are worn out at 3000 miles...if you have 3000 miles on your bike - come see us!
Front cupping is caused by worn fork seals
Old fork oil
Wrong springs
Worn springs
Loose head bearings
Worn head bearings
Misaligned wheel
Bent fork
Bent frame
Wrong tires
Cheap tires
Old tires
Fast riding
Bad roads
Over-inflation
Under-inflation
Over weight rider
And they will try to kill you, in the wet, the dry, on cold or hot surfaces.
Cupped rear tires are caused by:
Most of the above, and...
Big horse power
Bad shocks
Cheap shocks ("buy ours !")
Good, but worn shocks ("buy ours !")
Over-loaded cases
Trailer pulling
Wrong top case
And they will try to kill you, in the wet, the dry, on cold or hot surfaces.
Reading & listening to all of the above, the only thing that is clear to me is that neither the Soviets nor aliens are causing cupped scooter tires. Probably.
Oh yes, there
was one guy who said cupping is normal tire wear on a two wheeler.
But, this is so much fun - because everyone knows what causes cupping - but me.
Stig