Cycle News is a weekly magazine that covers all aspects of motorcycling including Supercross, Motocross and MotoGP as well as new motorcycles
Issue link: https://magazine.cyclenews.com/i/128389
5.1 pounds and is a completely sealed unit, impervious to dust and other foreign debris that might compromise its function. Instead of the shock piston acting on hydraulic fluid, it acts on air that is forced through plate valves into a secondary chamber. Damping is achieved by altering how qUickly the air can flow into the secondary chamber. With air being compressible, the air in the chamber provides the necessary spring effect in place of a traditional spring. One of the coolest things about the HP2's rear shock is the ease of setup. To set the preload on the shock, all you have to do is detach the bike's provided pump (similar to a portable cycling pump that stores under the seat on the frame rail), attach the pump to the shock's Schrader valve and either bleed off or pump up the volume of air in the shock to your requirements. Instead of the time-consuming process of hammering on the lockdown Paralever swingarmlshaft drive unit was changed for this application. The unit is now I.18 inches longer on the HP2 than the units on the GS and Adventure, and it has been beefed up to cope with requirements of serious off-road riding. The rear suspension system offers 10 inches of travel, considerably more than either of the other GS variations. In addition to the ease of setting up the bike's sag, I was very impressed with the performance of the air/spring. As a matter of fact, once I set up the bike, I almost forgot about the shock, which is a good thing, proving that the unit works exactly like a conventional unit with the added benefits of weight savings, reduced wear and simplicity. The steel, tubular spaceframe on the HP2 is derived from the R 900 R Dakar Rally machines raced by the factory BMW team in 1999-200 I. In the off-road riding situations that I rode the bike J <:> The air/spring is a completely sealed unit that uses air instead of hydraulic fluid for resistance. On the left is the cutaway and on the right is the external view. This is a view of the cockpit. Everything you need is there, and nothing that you don't. The HP2 features a 4Smm upside-down conventional cartridge fork with 10.63 inches of travel. GS Adventure are the chassis and suspension components. The HP2 is ready for battle. It's a lot less of a poser and a lot more of a performer. Sure the GS is a very capable motorcycle and probably the most wellrounded bike made, but the HP2 is a far more capable off-road machine. So what differentiates the HP2 from the rest of the GS line that makes it so much better? The suspension, for one. The HP2's telescopic front fork and innovative rear air/spring shock both perform extremely well in off-road riding situations. The front end of the bike features a S6 45mm inverted fork with 10.63 inches of travel, compared to 7.5 inches on the GS and 8.3 inches on the Adventure. The fork is fully adjustable for compression and rebound adjustment. BMW has designed the system so that preload settings can be set extremely firm without negatively affecting the compression circuit of the fork. The telescopic fork is far from innovative, but the same can't be said of the rear shock, which features an air/spring damper system. BMW claims that the system is the first of its type on a production motorcycle. The entire shock unit weighs only AUGUST 3,2005 • CYCLE NEWS The rear brake lever can be adjusted for height by flipping the little springmounted and elevated pad over the lower positioned pad. nut and pounding the preload adjuster with a hammer and punch and then measuring the sag, you simply pump it up (or air it down) and then look at the level bubble Gust like a level in a motor home) on the frame rail to see if the bubble is centered. If it is, you're in business. The other cool thing is that the changes are instantly noticeable, unlike on a motocross bike, when you really have to ride the bike for a couple of laps to feel the difference. On the HP2, the change is apparent the instant you hop back on the bike. In addition to new air/spring, the in, I was very impressed with the bike's ability to handle a variety of surfaces, from super-rough washboard high-speed sections, to rockand root-strewn Single-track with square-edged bumps. The suspension was compliant whether I was going 7 or 70 mph. For most riding conditions, there is more than enough suspension travel and spring, but this is still a heavy motorcycle. On the couple of jumps I launched the bike of, the HP2 handled the landings fine, but it definitely blew through the travel on the bigger hits. The HP2's chassis is unique to ride for a couple of reasons. First off, it is impossible to scoot your butt up and get your weight over the front while cornering, because when you try to stick your leg out, you hit the cylinder head. On the other hand, the bike's ultralow center of gravity makes maneuvering the bike at slow speed super easy; you can almost ride the bike like a trials bike. Another change from the standard G5 is the use of a 21 -inch front rim and tire combination. The rims are tubeless aluminum cross-spoke designs with 90/90-21 and 140/80-1 7 Metzler Karoo tires up front