You can fit a 7 speed hub in a 126 wide dropout spread, as I said the Dual drives require a 135 wide rear frame spread

Perhaps you can measure that? the inside the dropout faces width is the place to measure .

& just because it has 7 speeds does not mean it is a cassette , many make that assumption, falsely.


Sachs used to make a 7 by 3 hub, after the SRAM Buyout they no longer do .. its 8+..