Originally Posted by
Iride01
If your chain is too long, you can't expect the b-screw adjustment to do anything. Get the chain length correct first.
P.S.: When I say "90 degrees" I mean the angle made by the line that passes the centers of the pulleys to the ground. But this line can not go up to the center of the cogs. To do that, a specially tailored hanger for each bike and each cassette would be needed, but I think this is not what Shimano wanted to say...