I change my tire and adjust the belt to the spec. found in the manual (3/8 to 7/16 for a 07 road king) it is right on the money using the 10 lb. gauge. After riding for about ½ hour I got off my bike and check the belt and it was about ¼ and it felt tight like a banjo string. Any body knows if this is normal?

 

Yep, that's normal

 

Never paid much attention. I know most materials tend to expand or lengthen when subjected to heat (like the warming of an engine or friction between two things).

 

Yes, it's normal. Adjust it on the loose side of the recommended cold setting.

 

Thats what the wrench told me.

 

Theory tells you something should expand or stretch when it gets warmer, but the belts do just the opposite, they get tighter.

 

You are correct, belts (or rubber in its generic use) do 'shrink' when heated. Your choice of using the word 'theory' however is a bit odd.

 

You guys are pretty funny. Its the sprockets that expand when heated that cause the belts to tighten up. The belts have steal cables inside them that dont shrink. Use your brain a little.

 

steel will expand and shrink with heat.

 

Yes steel will expand when heated and cantract when cooled, you should no this. The sprockets happen to be made of HMMMMM I think some sort of metal!!! that means that its the one that expands, you know, gets larger, in return makes belt tighter.WOW Class dismised!