RC4WD has been involved with rock crawling from the start and continually comes up with a ton of new products every day. After a number of scale tires, RC4WD has decided to hit the comp market with their newest tire, the X-Lock. Measuring it at a whopping 5.5” tall, the X-Locks are made with RC4WD’s new X3 compound and feature a very sticky and stretchy rubber. The tread design features an “X” pattern in the center of the tread that is lower than the outside lugs. This helps the tires conform to the rocks by allowing the outside of the tire to slightly wrap around the rocks. The tires come with stock polyurethane foams; they fit the tires perfectly and don’t require any cutting.
I mounted the tires up to Mayhem Engineering’s Mayhem “7” aluminum rims. Each rim weighs in at 5.1 oz. I added an additional wrap of weight in the front tires and that added about 4 oz. of weight in each front tire for better vertical climbing ability.
The tires mounted up perfectly and I had no trouble setting the beads in the rims. Once the tires were cranked down, I installed them on our HBZ Warthog truck and proceeded to our local outdoor crawling spot. I started crawling around and the tires felt very solid. The additional ground clearance of the tires made going over obstacles much easier. I headed towards the more difficult sections and started going vertical. The tires felt pretty good, and liked to go slow. They hooked up well. After going through a battery pack, there was little wear on the tires and I swapped batteries and did some more crawling. I wanted to do a lot of testing side-hilling as these are some pretty tall tires. With the stock foams, these tires actually side-hilled very well. It seemed that no matter what direction I was climbing in, the tread was able to stay planted.
Overall, these tires worked well on a number of climbs. The tread hooked up and the additional ground clearance was welcomed on a number of climbs. The tires did feel a bit stiff on vertical climbs and the more difficult obstacles; I think switching to memory foams will help that. Running 1 1/2”of memory foam in the center and ¼” of stock foam on either side would work the best. This would allow most of the tread to conform to the rocks better, but not lose its side-hilling ability.