I want to change to 46/28 chainrings which is only possible using a triple crank as a double. Because of the jump in the chainrings I have to be careful about chain rubbing and dropping with the chain line. I will use 11-28 cassette and want to cross as much as possible since the 2 chainrings are only overlapping by around a third. I have a choice of getting a new JIS crank or switching to hollowtech 2. But Hollowtech is fixed with the chain line and cannot be adjusted, while JIS can be adjusted with the axle length. Also JIS would be 110/74 BCD while Hollowtech is 130/74 BCD, so I have to choose the correct size of chainring.

My current bike is dual drive with 135mm dropout. The middle of the cassette is around 45mm and single chainring at 48mm on the outside position of a double crank. The chain would drop if I used the largest cog. If I moved the chainring to the inside position then the chain would rub on the smaller cogs. I solved this by using a narrow wide chainring.

So with the vector, if the dropout is 135mm, then I assume the Hollowtech crank will not work well. Because the inner position ring will be at around 41mm and middle position at 46mm. The inner ring may be to far in to use the smallest few cogs. A 130mm dropout would move the cassette 2.5mm inward.