Dirt Wheels - December 2015

Rox Speed FX built nerf bars for the Ace that help protect it from trees and rocks damaging it or getting caught between the wheels.

ITP Baja Cross tires are mounted on ITP Black OPS SD dual-beadlock rims.

The tires won’t spin on the rims and will let you run on a flat tire until you can repair it.

An RVS Performance light bar is mounted on Rox Speed FX’s Ace roll cage to brighten up the night.

shocks by Motowoz have a dual-rate spring setup with crossover, rebound and spring preload adjustments. That is a first for the aftermarket Ace front suspension that we know of. The MacPherson struts don’t have enough room in the design to allow for all available shock adjustments, so Motowoz could only include rebound or compression adjustments. Since they designed their suspension with dual-rate springs, they went the route of having an adjustable rebound control. The rear Motowoz suspension is more adjustable with high- and low-speed compression adjustments built into the coil-over shocks.

clamp the 28 x 10-14 Bajacross ITP tires to the rims securely on the outside and inside tire beads, so there is absolutely no tire spin on the rim.

Polaris has been using their MacPherson-style front strut suspension setup in a lot of their machines for a while now. A dual-A-arm setup allows for more customization ability to install wider arms and long-travel suspension, but the MacPherson design keeps production costs down and, in some cases, makes a machine more stable. Motowoz designed an adjustable reservoir suspension with dual-rate springs for the front and rear of the Ace that use stock parts. The MacPherson front strut is still utilized in their design, while the rear shocks are stock replacements on the dual-A-arm setup. The new front

TEST RIDE

In stock form the Ace 570 has enough power to have a fun time, but the addition of an RVS Performance clutch kit helped propel the machine just as quick with the 3-inch-taller ITP tires. The kit boosts the bottom and mid-end power of the 570 engine and keep the rpm in a more usable range. The new ITP wheels and tires provide a lot more grip in all types of terrain than the stock tires did. They don’t have as much sidewall flex, they grip hard in turns, and claw through rock, mud and dirt. To help slow the machine down, DP brake pads were installed on all four corners of the racing Ace.

The Motowoz suspension made the biggest difference in the handling of the Ace 570. The adjustable suspension sucks up chop, whoops, landings, reduces roll and more with ease. The stock suspension made the Ace feel bouncy and rough, while the Motowoz setup is very smooth and improved the feel of the machine

The Rox Ace was designed as a GNCC racing machine, so protection is important. Rox Speed FX designed a front bumper that holds a winch and front bash plate.