Kyosho IFW457-7514 78mm Big Shock Spring Gray

A pair of 78mm Big Bore shock springs, wound with 1.4mm wire over 7.5 turns and color coded gray.

Kyosho's numbering encodes the specification directly: 7.5 turns of 1.4mm wire at a 78mm free length, in the MS medium short length class. The color code exists so a spring can be identified at a glance in the pit box rather than measured.

Within a fixed wire diameter and free length, fewer turns means a firmer spring. At 7.5 turns this is the stiffest of Kyosho's three 78mm springs in this wire gauge, firmer than both the 8 turn light blue and the 8.5 turn orange.

A firmer spring keeps the chassis flatter and resists squat and dive, which makes the car more responsive and more precise on high traction groomed surfaces, and holds it up better over big jump faces. The trade-off is that it skates on loose or rough ground where a softer spring would let the tires load up and find bite.

Note that Kyosho also makes a gray spring at this same 7.5 turn and 1.4mm rate in an 84mm free length, so check the length before ordering. Two are supplied.