Choosing a crank/bottom bracket interface

All Middleburn cranks are available in both ISIS and square taper configurations.

ISIS is an industry standard for bottom bracket / crank interfaces. It has a 10-spline contact area (similar to Shimano's Octalink design). The ISIS interface is stiffer than the square taper. There are many companies who make bottom brackets and cranks using this system.

Square taper is still capable enough for most riding styles. One benefit is a much larger choice of bottom brackets lengths.