Safety is first.
Japan has few courses of the closed unlike U.S.A.
It was weight to 152.2g before.
This class is called 150class.
It is said 150open class to 159.9g.
It is decided which class you hold it in every meeting place in Japan.
Heavy Disc has been used before in Japan.
I have used Disc of 170g before, too.
I've been throwing 150cl since I've moved to Japan. At first it was weird throwing light stuff, especially putters. The disc performs the same way that it would if it were in the 170s. The thing that changes is your form. My form became much more compact with more emphasis on snap. Now I don't think I'll ever go back to throwing the heavy weights like I used too.
The big problem is what Buchi stated before. Lack of 150 discs. There are moulds I want to try, but they aren't available. Innova has a wide variety which is good. Plus I pretty much know what I like to throw, and it's cool that I can score 150 CE Leopards, Teebirds, and Rocs cheaper than the heavier weights.
Jaime is correct. The weight limit is a safety precausion. Most courses here are not disc golf only courses. So many times in the summer people will be picnicing in the fairways, and the people in your group take turns forming a human barracade in front of them. Evidently, a 150cl disc hurts less than a heavier one. I can't wrap my brain around that one.
I love that the Japanese will go out of their way to be polite to people in this kind of situation. I would have never thought to form a human barricade around a group of "picnicer's." We just politely explain to people that they are putting themselves in harms way by being on the fairway.