We can kind of work out an up-sell for these cranks, but when you have Dennis Enarson on the same pair for more than a year, that seems to speak for itself. Full heat-treated arms that are fluted for added strength and stiffness. The larger, heat-treated 24mm hollow spindle prevents twisting and breakage common to smaller spindles. Complete with 3/8" ratchet spindle bolts for added convenience.