Honda Cr500r

HONDA CR500R

CYCLE WORLD TEST

High flying Honda

Motocross machines change more quickly than other bikes. Honda more than other factories makes major changes yearly. And during the past few years these changes have included new frames and new engines at the same time.

Thus, it’s news but not surprising that the 1984 Honda open motocrosser, the CR500R, consists of last year’s grips attached to this year’s everything else— frame, engine, wheels, hubs, the works.

In general, open class bikes are their engines, so we’ll begin there. The 1983 CR480R was adequate, but the rival factories were close to 500cc and the 480, actually 472cc, needed extra displacement to stay competitive. So the engine is bigger. The 89mm bore is the same, but the stroke has been increased 3mm, to 79mm, and the displacement is a true 491cc.

The engine has two exceptionally new features, one visible and one internal.

The internal concerns the weights on he crankshaft, and the way it’s different llustrates why Honda is so tough to beat.

Weight is bad, in that the heavier the engine, the more power it must produce for a given performance level. So a light flywheel or crankshaft weight is good. Except that effective power delivery, balance and so forth may sometimes require more weight than the engineers would otherwise like.

Basic physics provides the ordinary answer: if the flywheel is dished, with the mass at the outside edge, then it will act heavier than it is. Most factories use this technique, which works.

The drawback is that two-strokes are sort of supercharged. When the piston moves up, it pulls the fresh charge into the crankcase. When it moves down, it compresses the charge into the combustion chamber. The smaller the crankcase’s displacement, the more compression. A dished crank weight creates space that reduces this effect, which a concentrated weight doesn’t.

The median design team, so to speak, would choose between light or heavy weights, and between concentrated or dished weights.

Not at Honda. The 500’s weights are dished, but the cavity thus created is covered by a progressively die-formed plate. The weights are at the same time more effective and lighter, and don’t detract from the primary compression needed for power. All at once, and the sort of creativity and effort that must drive the other manufacturers to despair.

The second difference isn’t as clearly functional.

Air scoops.

Molded plastic scoops bolt to the engine and pipe, collecting and channelling air over the fins on the barrel and cylinder head.

The cylinder, meanwhile, is graced with additional fins that are longer and thinner, and the head fins are extra tall. Carburetion is a 38-mm Mikuni and there’s a new eight-petal reed valve. Internal gear ratios have been shuffled some and the final gearing altered but the end result (the figures you see on our data panel) are almost the same as before. The changes, of course, are made to enhance the different power characteristics of the longer stroke engine. There is a new clutch basket that uses last year’s fiber plates, new aluminum metal plates and stronger springs. The CDI ignition curve is different, as is the pipe which mounts on the right side of the bike this year. The package is wrapped in tiny new center cases with a right-side kick start lever.

The shift lever, kick start lever and tucked-in rear brake pedal are made of T-6 aluminum. T-6 aluminum is superior to the softer aluminum Honda has used in the past.

A new chrome-moly steel frame looks much like the 480 unit and has the same dimensions. It has a narrower mid-section and the frame tube that ran behind the carburetor has been eliminated. The sub-frame still bolts on, shared with the ’84 CR125 and 250.

Another new aluminum swing arm is used. It looks the same but is different due to the engine’s countershaft sprocket moving from the right side of the engine to the left. It is 9mm narrower at its widest point.

Honda’s excellent Pro-Link rear suspension has been tuned to near perfection for ’84. The rocker is slightly different, the strut between the rocker and the frame is 1.4 in. longer, and the swing arm brackets are moved slightly. These revisions reduce the progression of the rear suspension. On paper, the curve is flatter. It starts slightly stiffer and ends slightly stiffer. These seemingly minor changes make a big difference on the track. The bike feels more stable in turns and in deep sand whoops the shock doesn’t get hot as quickly.

The rear shock is slightly longer for 84 as well. This change is also for increased durability and less fade due to heat. The remote reservoir is moved to the right side of the frame for ’84. It’s still equipped with a 17-position compression damping adjuster. The recommended standard setting is between 10 and 13. We liked it best set at 15 for intermediate to first-year pro riders. Experienced pros thought 13 or 14 best. Rebound damping is adjustable too. The adjuster (at the bottom of the shock) requires a flat-blade screwdriver. Twenty-two clicks are offered, 12 to 15 is the recommended starting position. All adjustments are number of clicks from a fully seated position. Our riders liked the rebound set at 18, 19 or 20 clicks. Spring preload is adjustable. Honda recommends setting it so the rear of the bike sacks 3.9 in. with the rider aboard, fully clothed in motocross gear. That setting works well for most riders. Heavier and lighter springs are also available for those who need them.

The Showa forks have 43mm stanchion tubes, 12 in. of travel and air valves. Our bike was the first in this country and Honda had no information about these forks. They appear the same except for more compression damping positions, 16 compared with 12 last year. The stock setting is backed all the way out, counterclockwise. Fully seated, 16 clicks in, is the stiffest compression damping. Most of our riders liked them

set at 16 clicks. One pro iked them best set at 14. That same rider preferred the fork oil level raised from the standard 6.4 in. level to the maximum of 5.7 in. Level changes make a huge difference in the way the CR handles. Changes should be made in ‘A-in. increments until the rider is satisfied.

New hubs are used at both ends of the bike. At the front, there’s a spool hub, the better to mount a disc. The disc is the same outside diameter as the one used on Honda’s XR500R but it’s 0.02 in. thinner to reduce weight. A dual-piston caliper is strong but not grabby. A small master cylinder mounts on the right side of the handlebars. It is about half the size of the XR500 part, with a smaller piston for greater pressure on the disc. A D.I.D. aluminum rim is laced to the hub with straight-pull spokes. On the XRs the spokes are a constant diameter, the CR spokes are 0.5mm thicker at the hub end. Our test bike was equipped with aluminum spoke nipples. They are lighter than steel spoke nipples but not as strong, and their edges can be rounded if they are not tightened carefully.

Moving the countershaft sprocket from right to left required doing the same with the rear wheel sprocket, which required a new hub. The new hub has the brake on the right side so brake linkage isn’t complicated. Honda claims the new hub is actually lighter than the conical design used last year. A new rear brake backing plate reduces some of the squeal associated with the ’83 rear brake. The aluminum rear brake pedal has its back section tucked behind frame rails so the rider’s boot can’t catch on it. A braided steel cable connects it to the rear brake arm and is easily adjusted with a wing nut.

A new, 2.5 in. longer silencer is fitted to the end of the pipe. It has double mounts so it will stay on the bike through long, rough races and the troublesome rear clamp between the silencer and pipe end has been eliminated.

All of the CR500R’s plastic parts are, once again, new. The gas tank rests lower on the frame and there is a new gas cap. The cap is so neat, and so simple and logical, we wonder why it took so long for someone to come up with it. Its edges are scalloped radically so it’s easy to grip, and its profile is rounded so it won’t hurt the rider if he slides into it. The new petcock is mounted so its control lever points in, where the rider’s knee doesn’t shut it off and the lever is longer. A larger, fatter lever end makes it easy to operate with gloves on.

Side number plates are a little more square which makes number installation easier, especially if you have a two or three digit number. The front number plate attaches without rubber bands this year and it is slightly larger. The bottom of the front plate has a plastic prong on each side that plugs into the lower triple clamp. The top of the plate still bolts to the top triple clamp with one screw.

Front and rear fenders look unchanged but the rear one is mounted with two screws at the top instead of one. The front fender is the same shape and bolt pattern but different plastic is used. In fact, all of the ’84’s plastic is different. It has more shine and it’s supposed to retain the sheen longer.

The airbox intake boot is moved from right to left and the airbox top is modified for better protection from water splash. It is equipped with a nice, nonrestrictive cap that only covers the foam cleaner.

Lowering the top of the tank on the frame gave side benefits; the front part of the seat can be lower and flatter. It’s fitted with an excellent form-hugging cover with a pigskin-like texture. And like last year’s CR, the foam is a perfect density and shape.

The flatter seat front makes it possible

to slide farther forward on the CR500. It would also make it possible to stick the handlebars into your side in a full-lock slide with last year’s bars. Naturally, new, straighter bend handlebars are used for ’84.

The newness extends to the throttle and hand levers. The front part of the levers are wider and easier on the rider’s fingers. The front brake lever is more dog-legged than the clutch so it clears the throttle housing when pulled way back. It has a great screw-type adjuster that allows infinite adjustment. The hand grips are the same as before. They are the best grips ever put on a dirt bike, soft but tough and long-lasting. And the rider’s hands don’t slip, even when they are caked with mud.

Despite all of the changes for 1984, the CR500R still looks like a CR. That’s good. Giving the CR the “sit test” at the corner Honda store, one is instantly aware of changes. First, it’s easy for almost anyone over 5-ft-8 to plant both feet firmly on the floor. The new frame, lower gas tank and flatter seat have effectively combined to lower the seat height to a comfortable 36.6 in. unladen. With a rider aboard, the cushy suspension sacks some, and touching the ground is pleasantly easy.

Out at the racetrack, with riding boots on, touching the ground really is easy. And starting the beast is actually pleasant, for a change. The right-side kick start lever shouldn’t make any difference but it does. The lever is lower on the engine and that, combined with the reduced seat height, means you can get your boot on top of the pedal without standing on something first. The lever engages quickly and it’s easy to get a good, long swipe, so the engine turns over fast enough for consistent first-kick starts. Finally.

There is noticeable engine vibration as the engine warms but it mostly disappears after the easy-pulling clutch is released. Low gear is quite tall and the clutch engages suddenly while the clutch lever is close to the bars. Shifts are smooth, precise and short. The internal ratios are close but the CR’s top speed is enough, even for tracks with long straights. The longer-stroke 500 still behaves a lot like the 480. It winds easily and smoothly. Carburation is spot on except right off idle where it’s a little rich. As the engine warms more, most of the richness disappears when a pro rider is aboard. Others will want to replace the stock 68 pilot jet with a 62 or 65. That should clean up the low speed burble.

The new engine is plenty fast. It holds the front tire off the ground in any gear with a simple flick of the right wrist. The longer stroke and new flywheel put the power to the ground. Wheelspin has been reduced significantly with the new engine.

Most of our testing was done with outside temperatures around 110°. The engine ran strongly without any indication of power fade from heat. The air scoops work well. The right side scoop keeps the rider's leg away from the pipe and doesn’t catch on knee guards, a concern of several test riders before trying the bike.

The ’84 CR500R has Dunlop K490 tires instead of the Bridgestones of last year. They are a good choice for many parts of the country. If the ground is sandy, loamy or wet, they work well. For Southern California’s slippery hardpack,> other tires will work better. Even so, there is a big improvement in handling over the 480, which was no slouch. The new rear suspension progression is noticed immediately; the bike has a firmer overall ride although it’s still comfortable. The firmer action enhances steering precision to the point where thinking about a direction change is all that’s necessary for minor maneuvers. And the bike’s balance is wonderful. On the scales it almost hit the perfect 50/50 weight distribution. It’s noticeable over jumps and in corners. The front wheel never washes, the back never tries to slide over the berm. Wheelies are controlled with absolutely no tendency to loop or fall to the side.

HONDA CR500R

The 480’s brakes were good —the 500’s are great. The disc provides strong, predictable stopping power and never changes due to water. Grabbing a handful of front brake during a panic situation won’t send the rider over the bars. The unit is extremely progressive and non-grabby. The rear brake is much the same in action as last year’s bike; it is strong enough to do the job but not so strong it stalls the engine. It, too, is progressive and maintains consistency throughout long motos.

Problems and complaints were few during the CR500R test. The footpegs are placed too low on the frame and the rider’s feet hit the ground after landing from extra-high jumps. We also broke some spoke nipples in the rear wheel.

Honda discovered the weak spoke nipples after the bikes were shipped, but assured us no CR with aluminum spoke nipples would get to a dealer. Honda is replacing the wheel assemblies before the bikes leave the warehouse, installing wheels with steel spoke nipples.

The footpeg location isn’t as serious a problem, and some of our riders never noticed it. If an owner is bothered by the peg location, it shouldn’t be too hard to weld something on top of them.

That’s it for failures and complaints. Not bad.

Last year’s CR480R was the best open motocrosser. The new CR500R is miles ahead of the 480. Isl