Nike Pegasus 41 vs Nike Pegasus 42:
Which to Choose

The headline difference is geometry and Air Zoom layout. The 41 runs a traditional 10mm drop and uses two separate Air Zoom units — one in the heel, one in the forefoot — paired with moderately soft ReactX for a planted, predictable landing with a subtle lift once you push the pace. The 42 moves to a single curved, full-length Air Zoom unit running the whole length of the midsole, which gives a more continuous, distinct pop through the whole footstrike, but Nike also went firmer and much more heel-biased: the 42 carries a tall 14mm offset versus the 41's 10mm, so you feel the heel on every stride and the ride is clearly businesslike at truly slow paces, warming up once you settle into a rhythm. That firmness and the higher heel make the 42 lean toward longer, steadier efforts — its best distances shift up to 10K, half, and full marathon, where the 41 is pitched at 5K, 10K, and half, making the older shoe the slightly more lively, versatile one at shorter, uptempo work. Both share the same neutral, wide, well-planted platform with no pronation support, the same breathable engineered mesh upper, durable rubber outsole, and the same optimal everyday training window of roughly 5:00–6:00 min/km, with a fastest effective zone around 4:45–5:15 min/km for each — neither is a speed tool, and the 42's extra weight and tall heel reinforce that it's a trainer, not a racer. Net: this is an evolution in ride character, not a leap in capability; the 42 trades a touch of the 41's softer, lower-slung versatility for a firmer, taller, more long-run-oriented platform.