They are also of the "straight design, .i.e the fork legs are parallel with the head tube as opposed to the legs being angled forward slightly giving the bicycle a longer wheelbase. To compensate the Bottema M-1 fork had a one inch axle lead.
In terms of design, they have a "straight configuration" where the fork legs are aligned with the head tube, as opposed to the slightly angled setup that would increase the wheelbase length. The Bottema M-1 fork addressed this by introducing a one-inch offset from the front axle.