Just bought a new Avon rear tire and had it mounted today. The shop that mounted it told me that the tire needed 2 oz. of weights to make it balanced and that was very unusual and he even suggested I got a bad tire. On a side note, he tried to sell me something called dynobeads?. Anyhow, is it true about a new tire being bad if it needs 2 oz of weights and what is dynobeads?