WHEN DIRT AND ASPHALT MEET BIG BIKES
Story By Jimmy Lewis
Photo By Adam Booth
Adventure bikes are big machines and riders demand that they perform both on the dirt and on the road, so choosing a tire that can do both is ideal. In addition, some of these big machines see only a little dirt time, so an aggressive tire for off-road isn’t always the best and will wear out quickly on the pavement. Whatever your dirt-to-street preference, read on to find out which tire suits your adventure needs.
Dunlop’s long-wearing 606 has a dedicated following, especially the front tire on heavier bikes. In fact, a lot of riders prefer to pair it with Dunlop’s 908 rear for long run rides. Both tires have a consistent bite in all conditions of dirt, and the 606 doesn’t degrade as much as most tires since it isn’t that strong to begin with. The high point is durability; the weakness is wandering in sand. The 606 is most comparable to the Pirelli MT 21 and nearly identical in performance. That means this is a very true dirt-focused DOT tire.
The Big Block is direct competition with the Continental TKC 80, and it is very close yet very different. The Kenda is a little off in durability and on-road feel, where the tire wanders on wavy pavement and in turns, especially when the tire is new. Off-road the tire’s traction is just as good as the TKC. Where the Big Block shines is on washboard roads with superb bump compliance, actually aiding the suspension on every bike we tested them on. To combat durability, Kenda has since beefed up block sizing on the center knobbies.
The standard for off-road riding adventure tires that have to perform on road as well as off is the TKC 80. Although criticized for its on-road life span by highway types, there is no tire that is as 50/50 capable, especially on the twin-cylinder machines they are built for, most notably the BMW GS. The TKCs have a very solid feel on the pavement that blows away any other open-block design, but also offer a predictable and consistent bite off-road, even if it isn’t super grabby like a true knobby. If you ride a really big bike in the dirt, consider these a necessary safety precaution.
908 RALLY RAID
The 908 Rally Raid was designed for high-horsepower dirt riding, and it delivers a very good match of durability and performance when used on the right bikes. The unique “Chevy” center block adds life, especially when ridden on-road, while the traction lost off-road is minimal and only felt when in a straight line. The side bite of the rear is very good, but you have to remember it can get loose when you stand it back up while sliding. The front is too aggressive for any real street use and is pretty stiff, so it only works properly on a very heavy dirt bike — then it performs just like an off-road–only knobby. Side knob chunking on the front was common.
The Parker is a multi-directional tire designed for hard and intermediate terrain, and it really shines in hardpack with loose or sandy soil on top. The bite is strong and consistent with a compound that seeks traction when needed. We preferred to run with the intermediate direction on the rear and the hard direction on the front because the braking performance was excellent (best in test) in those directions with the bike tracking very straight. The front tire actually mushrooms more than it wears, which was strange, but considering the traction the durability was excellent.
KAROO 2(T) AND MCE KAROO (T)
The Karoo is Metzeler’s entry into long-wearing tires for big bikes for those who seek more on-road stick and durability over dirt performance from a 50/50 open-block tire. The large block lacks outright traction and suffers on bite but for the right rider (easier on the throttle) this isn’t a concern, yet the way we tested and rode off-road the durability suffered due to all the spinning. For us the small gain off-road, compared to the TKC or Big Block, overall performance wasn’t enough to justify the trade-off. The front was excellent on-road but really suffered in soft or muddy conditions.
KAROO AND KAROO 2
Designed for rally and Baja racing, the Karoo is a tough tire that packs durability and ruggedness and tries as hard as it can to keep the traction high. As a bigger rear tire it bites good when new, then falls off and lasts forever in the slick and spinning environment that type of desert racing can be, lasting a long time and protecting from flats. It floats well in sand but gets a little loose when sliding. The front’s traction is very mediocre, yet it wears long and doesn’t like wet or sandy conditions. The on-road ride is vibration-intensive compared to the bigger-block tires, and street traction is poor. We would pair the rear with another tire, like the Pirelli MT 21.
If we were to pick a standard for a dual-purpose tire that had to work everywhere (including some on-road), have enough off-road traction to not suffer much and last forever with a consistent and predictable performance through the life of the tire, the MT 21 is that benchmark. It is never great at anything, but wrapped all together as a package, front and rear, this set is hard to beat for your license plate-wearing dirt bike.
PRO FIM AND RALLY MT18
As a dirt-focused pair of tires, this mismatched-in-name set (there isn’t a DOT MT18 front) is good for a dirt lover needing durable and high-performance tires that start off high and remain consistent for the life of the tire. They work better on harder dirt and like more abusive and rocky riding. The rear MT18 takes a licking and keeps on grabbing, and works exceptionally in the sand during the first part of its life. Even though the knobs chunk more than others, the performance doesn’t suffer.
SIX DAYS EXTREME
These were the lightest tires in this comparison. The SDEs were the traction kings in loam or good dirt conditions, giving up nothing to any dirt tire and even showing them a thing or two in grass track or EnduroCross situations. The performance stays high as they wear compared to others, but the carcass of the tire (mostly the front) often gives out before the knobs seem to. The Six Days are very tunable with pressure. If you need to race an enduro on a DOT tire, use these. Sure they squirmed on-road, but we didn’t care.
Nearly identical looking to the Metzeler Six Days Extreme, the Pro FIM acts like a stiffer and harder tire built from a slightly harder rubber. It didn’t seem to last much longer than the Six Days (the rear the same, the front carcass definitely longer) as the Pirelli chunked on rocks more than the Metzeler did. Traction was excellent in this comparison except on the hard terrain with loose stuff on top where it got loose a little easy. It did perform slightly better on-road for those who are concerned.
A specific rally racing tire set, the Rallys are tough and heavy. The rear has decent bite when new but falls off quickly as the edges go away, then it seems like the rear tire never wears, even when being abused and spinning. As the side knobs on the rear wear, the sliding slowly becomes less consistent. The front has better bite when new, but there was a quick drop-off in performance at about 1,200 miles when the second row rounded. These tires laugh at hitting rocks.