Over the summer, Arctic Cat engineers gave some additional race-focussed love to the 2015 ZR 4000 RR.
While bereft of some of the full-bore race treatments featured on the new 6000R XC model (namely the revised rear suspension, clear fuel tank, TOS sprocket and grippy seat cover), the 4000 RR does get some key upgrades:
• ProCross chassis with added cross-country racing features for improved performance:
– Additional tunnel brace added around lower chaincase for increased strength
– New outer rear suspension brackets for increased strength
– Front bulkhead, front spars, and rear spars use 10mm hardware for increased strength
• 43.5-in. wide Arctic Race Front Suspension:
– This compares to the 42-in. ski stance on other ProCross models
– Race-style spindle/ski damper adds pressure to the rear of the ski for improved cornering and handling
– Larger diameter tie rods (the same as 2014 race sleds) for increased strength
– 5-in. Trail Skis (compared to a 6-in. wide skis on other models) enable the snowmobile to maintain the required 48-in overall vehicle width required in certain states and provinces
• Offset Ski spacers for Adjustable Ski Stance:
– Additional ski spacing options for Ice racing applications
• FOX FLOAT EVOL RC ski shocks with wide-range, hand-adjustable compression and rebound adjustments:
– Different length to accept the wider ski stance
– XC race calibration, which is a little stiffer than the current RR package
• Stationary Clutch Guard with Spare Belt mounting:
– New clutch guard design with exhaust pipe mount and spare belt mount
• Race Proven TEAM Secondary Clutch with Race Driven Shaft
– TSS-04 TEAM clutch, same model that has been used on the 2014 (and prior) XC race sleds
– Race driven shaft to mate with the TEAM Secondary clutch
• Race Proven Brake Caliper and Pads for improved wear and increased stopping power:
-Same Brake Caliper as 2014 XC Race Sled
-Larger bridge bolts for increased stiffness
-Low-pressure seals for less resistance when the brake lever is pulled
-Offset friction material on brake pads for more even wear under high pressure
– New brake pad friction material has increased braking power at elevated brake temperatures
Unchanged from the specifications that Cat indicated this spring, but still noteworthy:
• 4 Position Rear Coupling for adjustable transfer control
• Race SLIDE-ACTION Rear Suspension
• 2.86-in. Pitch 9-tooth Track Drive shaft
• 2.86-in. Pitch 15 x 129 x 1.25-in. Cobra Track
I already had a lot of love for the pre-production ZR 4000 RR that I reviewed last spring. The recent improvements indicated here have undoubtedly made this a better race sled (and high-performance romper-stomper).
In other words, more love.
Thanks for reading.