[MAStuart]

Curtis at Trigo also measured a wheel again. He found a flaw in his calculations. He now said the hub is about 3 5/16 to 3 3/8 thick. This would give another turn of threads or so. This would give me about 5 to 5 1/2 threads of engagement.

The newer wheel produced by trigo now have a thicker hub than original wheels so depending on the length of your drive hub you may or may not have enough thread engagement.

How many spinner thread do they need to be on to be considered safe?

Mark