The short version
At 182g in a UK 9 the Nimbus Kite SL is the lightest shoe in this test that still passes our peak-impact threshold. It is a tempo and race-day tool and it is honest about that.
What the lab measured
Peak vertical impact at 4:00/km pace stayed under our 2.8 body-weight ceiling, which several heavier shoes failed. Energy return was 72.1 percent. Durometer 46C, soft, and it softened a further nine points by 400km.
Stack measured 32mm heel, 26mm forefoot. Upper is a single-layer monofilament mesh with almost no reinforcement, which is where the weight saving comes from.
Where it disappoints
Lifespan. The foam is past its useful window by around 300km. Treat it as a 250km race shoe and the value maths works; treat it as a trainer and it does not.
Verdict
Best for tempo. Narrow purpose, executed properly, with no attempt to oversell it as something else.