Radio Controlled Car Action – Test Bench: Pro-Spec Shocks

Radio Controlled Car Action – Test Bench
TRIED – TESTED – TORTURED

On the heels of the release of their first full-blown short course truck kit, the PRO-2, Pro-Line has released the Pro-Spec as an upgrade over their Power Stroke shocks. The name Pro-Spec promises a higher level of performance and refinement over the standard racing shock design, and when it comes down to “What makes this shock better?” the answer is in the small details. Let’s take a look…

The Pro-Specs are sold in pairs. A variety of pistons are included, and they’re molded in slick Delrin to reduce friction. Shock assembly tools are also provided with the black parts tree. Note that there are just two shaft seals, one per shock body. Instead of o-rings, the seals are X-rings. They’re still shaped like rings of course, but the seal’s cross-section is an x-shape, which provides two contact points against the shock shaft.

The basic list of internal parts is exactly what you’d expect in a shock, but a closer look reveals some of what makes the Pro-Spec a top-notch damper. Pro-Line developed all-new delrin pistons for these shocks that are rigid and strong but smooth to reduce friction inside the body of the shock. The pistons are mounted on hardened-chrome shock shafts that provide a strong and silky smooth movement through the seal assembly. Rather than using a pair of E-clips to hold the piston in place, the top of the shaft is thread and uses a washer and locknut to keep the piston square to the shaft at all times for consistent damping.

The Pro-Spec shock features a single X-ring that has a concave profile and looks like an X when viewed from the side rather than a pair of rounded O-rings. These seals provide a pair of surfaces against the shaft but reduce friction as the shock moves. The seals are housed in a lower portion of the body along with a set of delrin guides, which are all loaded from the outside and held in place by an aluminum cap for easy repair and replacement without taking the whole shock apart. The shock bodies are machined from a single piece of aluminum that is threaded and accepts a blue anodized aluminum adjustment collar. On the top, the cap is held in place by another aluminum cap and features a bleeder screw that allows air and excess fluid to escape when building the shock.

The shocks are an emulsion design, meaning they do not use a bladder that creates a pocket of air inside the shock to allow for the displacement of the piston as it moves. In an emulsion shock, the shock cap is dome shaped and mixes air into the shock fluid to make up the displacement; a proven, easier to build, and more reliable design.

I replaced the shocks on my Pro-Line PRO-2 with the Pro-Specs to test them out at our local track and found them to be more consistent and stable. Through bumpy sections of the track, the Pro-Specs were responsive and provided consistent traction throughout the course. The most important difference in these shocks is their consistency. Throughout an entire evening of racing, the Pro-Spec shocks operated smoothly as expected lap after lap. Pro-Line offers optional Tuning Spring sets that offer “super-soft,” “soft,” “medium,” “hard,” and “super hard” spring rates (the Pro- Spec kit includes yellow “medium”) to give you some options. I recommend picking it up. The Pro-Spec shock kit may be one of the more expensive options on the market, but only by a small amount, and for the attention to detail, added performance, and durability, they’re worth the price! With unique features that change the game, the Pro-Spec kit alongside the PRO-2 SCT is an exciting next step in the evolution of Pro-Line’s race program –Erich Reichert

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