wrinkle tanks

[myhondas]

What year / serial # did the wrinkle tank first show up and when did it disappear from production?

[kp]

There are three known types of wrinkle tanks. First 2 were on bikes up to around VIN 2,000. The third and more common tanks were used up to around VIN16,000 to 18,000. Maybe someone knows more accurately but certainly past VIN 15,000 

[steff750]

hi just too confirm what kp has already said
i dont think they made them much later than summer 1970
i have two 1970 cb750 k0's that both had wrinkle tanks vin#15000 and a vin#18000
i also have one 1970 cb750 vin#15000 without a wrinkle tank but im sure this tank is a new replacement and not the original one

[tomcourtney]

My old sandy 1006958 did not have a wrinkle and the previous owner swears it was the original? and other later bikes i have had did, so i think like the seats, as production ramped up there was more than one die or source of manufacturing, Honda had many plants..TC