Valbrona wrote:I want four chainrings.
I've got 4 chainrings with my setup, Schlumpf HSD with twin chainrings .
38-55 and 95-137.5......
It's not big chainrings that are useful, it's small ones.
So it's possible to bolt an adapter to the inside of a triple.
But to go much above 24t difference at the front, you need to start modding the derailleur cage.
That trick was done whan max sprocket size was only around 28t.
Luck ......