Traxxas 7457 XX-Long Progressive Springs Ultra Shocks

The Traxxas 7457 is a pair of progressive-rate springs for XX-long Traxxas Ultra Shocks. They are custom-wound to provide responsive control over small bumps, with a progressively stiffer rate that absorbs harder impacts.

Progressive winding is what distinguishes these from a standard linear spring. A linear spring has one rate throughout its travel, which forces a compromise: soft enough to absorb small surface texture means too soft to handle a big landing, and firm enough for landings means the car skates over small bumps instead of tracking them.

A progressive spring resolves that. It is soft at the start of its travel where the suspension is dealing with surface texture and small impacts, then stiffens as it compresses further to catch heavy hits without bottoming out.

That characteristic suits rally driving particularly well, since a rally car has to deal with both continuous small-amplitude chatter from loose surfaces and occasional large impacts from ruts, jumps, and kerbs within the same run.

These are XX-long springs specifically, so confirm your shocks take that length before ordering. Ultra Shock springs come in several lengths that are not interchangeable.

Sold as a pair. Genuine Traxxas part.