Even if you're an expert off-road rider, there's a good chance that you've never experimented with grooving your own rear tire. While it's certainly not wise to randomly hack up your perfectly good stock rubber, there's a lot you can do to extend the performance-and quite possibly the life-of your tire by setting it up for nasty off-road usage. Here are a few tips from Monster Energy Kawasaki Off-Road mechanic Tanner Harding on how he prepares the tires for Ricky Dietrich's EnduroCross machine.
"There's a lot that I do to Ricky's rear tire to modify it for EnduroCross racing. I start with an 18-inch Dunlop Geomax MX51 rear. To groove the tire I use a gun that is pressure activated. As soon as I put pressure to the tire the blade starts heating up and it will melt through the knob. As soon as I release contact on it the blade starts cooling down and doesn't burn or anything like that, so it's fairly safe. Using this special tool, I groove horizontal grooves on the center contact knobs that are going to be touching the ground in a straight line. Depending on the kind of track that Ricky is racing on, I will also groove horizontally into the shoulder knobs. We've experimented with diagonal grooves on the shoulder knobs for turning, but Ricky has found that he likes horizontal because he wants straight-line traction through the rocks and logs.
"I haven't had any issues with chunking when I do this to Ricky's tire. When the tire is flexing because it's grooved like this, I think it actually keeps the knobs from chunking as badly because the knob has more give and can kind of conform to the terrain rather than just being stiff and chunking. We never, ever groove the front tire. We run a non-production Dunlop front-we have it labeled as our EnduroCross front that we don't really use elsewhere-and it works pretty well through the rocks and logs.
"The average rider will want to groove his or her rear knobs because it makes the tire feel softer. If you know you're going to be riding in a certain place with maybe a lot of log crossings or possibly in a special test in really rocky terrain, grooving is great to do. When you get that extra edge it will make that tire a lot softer and really grip on those rocks and logs. For racing, we don't run tubes, we run Tire Balls. We run fewer Tire Balls with low pressure because we really want to keep these tires soft. That's really the key there because if you run low pressure with a tube, you'll get pinch flats."