Published on November 27th, 2013 | by Joe0
Grooved GBC Bomb Squad MX Tire Test, with VIDEO
Custom grooving yields big bite on loamy tracks, and how they compare to stock GBC Bomb Squad tires.
Last year we tested a set of GBC Bomb Squad motocross tires and found them to be a long-lasting track tire that offered good performance on intermediate to hard dry tracks, as long as you ran the ideal tire pressure, which proved to be 7 pounds rear and 10 pounds front.
The front tires’ performance was pretty predictable and consistent on various track surfaces; however, the more loose or deeply tilled the track’s surface was, the rear tires’ forward traction and side bite in corners suffered,.
The GBC Bomb Squad tires’ closely-spaced knobs were designed to be grooved for specific track conditions, so we decided to try a grooving pattern recommended to us by GBC’s Kory Ellis, in the hopes of making the Bomb Squad tires perform on a freshly tilled track.
To put our grooved Bomb Squad tires to the test, we met up with Dave Trimble at his freshly tilled, private practice track. We also brought out a set of stock un-grooved Bomb Squads for back-to-back lap time comparisons. After a couple of warm-up laps, Dave ran a two-lap moto from a standing start to test the tires’ holeshot potential. The front tires were inflated to 10 pounds of pressure, and both the grooved and ungrooved set of rear tires were inflated to 7 psi.
Up first were the ungrooved tires. On the holeshot, the tires spun when Dave dumped the clutch. After upshifting, the rear end kicked out as the tires continued spinning wildly. Once out on the track, the tires performed well on the parts of the track where a line started developing after practice. On corners that were deeply tilled, you could only get so much drive before the rear end would start spinning and step out. Dave finished two laps with the stock Bomb Squad tires in a time of 2:01:19
After a quick rear wheel swap, it was time to run the grooved tires. When Dave dumped the clutch, the tires spun until he upshifted. The tires then hooked up and drove hard through the tilled soil. The grooved Bomb Squads clearly outperformed the stock tires on the start.The most challenging corners for the stock GBC’s could be attacked with more throttle and body English, enhancing corner exit speeds, and making the following jumps easier to clear.
On a couple of corners that weren’t heavily tilled where a hard line was developing, the grooved tires provided perhaps a bit too much side bite. Adding a half pound to a pound of air pressure could help loosen them back up a bit on a packed-in race line.
Dave’s second two-lap moto ended in 1:58:73, making the grooved bomb squads 2.46 seconds faster over the course of two laps.
Dave felt that the grooved Bomb Squad tires had what it took to be competitive on a loamy, tilled track. They should also work well on sandy or muddy tracks. Based on the amount of wear our grooved Bomb Squads were showing after their short moto and another hour of filming, a grooved set of Bomb Squads should still outlast any sticky compound motocross tire we’ve tried.
We hope GBC will consider offering a few variations of the Bomb Squad MX tires, eliminating the need for the end user to groove their own tires. With pricing at the lower end of most premium tires and excellent wear characteristics, the Bomb Squad tires offer good value. Having tested the grooved pair, we could also call them versatile and competitive.
Product: Bomb Squad MX Tires
18X10-8 Rear $88,74
20×6-10 Front $73,63
GBC Bomb Squad MX Tires, Custom Grooved
Summary: Grooved, they worked well in loam and were still durable. We hope GBC will consider offering a few variations of the Bomb Squad MX tires, eliminating the need for the end user to groove their own tires.