The (junior) Racer's Edge
THE (JUNIOR) RACER'S EDGE
A DG-Converted Suzuki RM80, for Kids Who Can Afford to Go to the Head of the Class
Len Vucci
Speed costs money-how fast do you want to spend?” This simple philosophy has been applied to the Suzuki RM80B by DG Performance Specialties with impressive results.
DG specializes in motocross performance modifications. It is a true performance facility, often working in conjunction with factory personnel on developmental engineering. Professional engineering does not come cheap. Effective engineering is even more expensive.
An 80-cc minibike which, at a local motocross track, turns laps only three seconds off 125-cc expert times is an example of effective engineering.
The price for this professionalism is $1595; nearly three times the original $535 sticker. The DG RM80 was built by and for professionals. Its only purpose: winning.
And it does. In each of its seven outings to date, the DG-built mini-missileeasily won its class. If winning is what you want, the DG RM80 is the weapon on which to do it.
The grand-point-six tab includes the services of a factory mechanic for the buyer’s first race anywhere in the continental USA. Right, your own personal wrench.
Individual hop-up components are available for a stock RM80 as shown by the accompanying list. The all-out racer, though, is not simply a stocker-cum-boltons. Rather, it is an entity resulting from a concentrated, directed effort. The total is definitely greater than the sum of the parts.
Let’s see what constitutes this minimarvel.
ENGINE
The gold-anodized, radially finned cylinder head is immediately apparent. It has approximately twice the surface area of a stock head and its fin design further increases the engine/air heat exchange. The combustion chamber configuration is quite different than the OEM head, and has a substantially higher compression ratio.
The cylinder is radically ported, virtually to the limits of the stock barrel-liner casting. The piston is stock except for edge chamfering. Benefit to the privateer is obvious: Replacement pistons and rings are as near as the closest Suzuki dealer, and require a minimum of expertise and expense to install properly.
The bottom-end is stock, and has held up to the demands placed on it. Ditto the connecting rod. Development of a bulletproof rod is currently under way though.
CARBURETION
The original 24-mm Mikuni is replaced by one of two larger units. The first is the 28-mm version, which, until recently, was the largest in this series of carburetors. But the little DG beastie can handle a bigger throat, so it gets one: a new small-body 30mm Mikuni. This one gives a 56 percent increase in venturi area over stock. For comparison, the carb on the Suzuki TS250 elsewhere in this issue is only 28 millimeters! The enormous fuel/air appetite of this 80 is a good sign of the power produced. And, to prevent a possible nasty case of indigestion, the steel reed petals are replaced by the edible fiber variety.
EXHAUST SYSTEM
The dynamics of the DG pipe are quite different from the original exhaust. Shown in the photo is the Pro model exhaust. The pipe makes good use of carb and cylinder modifications, and produces power which rivals the stocker on the bottom-end, and is no comparison on top. A usable powerband of 4000-10,000 rpm is claimed.
That ain’t all. Much time went into exhaust development, producing a secondgeneration pipe called the Super Pro. When used with the 30-mm carb. powerband and power are both bumped up. Useful rev range then becomes 600013,000 rpm, and power output is rated simply abundant.
SUSPENSION
The forks are stock except for the addition of air pressure caps. Ten-weight fork oil is most often used; some front-end tuning is possible by varying oil viscosity and air pressure.
Looking aft, the DG RM’s race-bred heritage is obvious. The aluminum swing arm, riding on two-piece steel/bronze bushings, is longer and stronger than stock, providing 7.5 inches of travel. Providing support is a pair of 13.5-in. S&W shocks in lay-down position. Shock damping rate is soft, and 60/90 progressive springs are fitted. Long travel rears make for an occasional errant chain, so a tensioner is also mounted.
WHEEL ASSEMBLIES
While adequate for a spritely stocker, the original wheel assemblies would not do for the serious racer. Except for the hub, the original 2.50-16 wheel is discarded. A 17-inch K&L aluminum rim is laced to the hub with eight-gauge spokes, and a 2.75 Nan Kang tire fitted. The rear is set up similarly, with a 3.50-14 Nan Kang providing traction. As a neat touch, both rims are anodized a high-zoot gold.
FINAL DRIVE
To take advantage of the engine’s willingness to rev, the rear sprocket is a 48 tooth, compared to the Stocker’s 46. So the engine’s torque doesn’t take advantage of the chain, a heavy-duty ISUBAKI #428H chain is fitted.
ACCESSORY COMPONENTS
Completing the miniscule racer are a few miscellaneous components. Among them are a quick-throttle and DG emblazoned seat cover. The others can be found in the accompanying chart.
KIT COMPONENTS
If you feel the urge but don’t have the allowance for the factory bike, there are alternatives. Different stage kits are available, as are various individual components. Cylinder and wheel hubs are modified on an exchange basis.
While the components are designed to work best in combination, excellent results can be had from any of the separate parts.
DG RM80B IMPRESSIONS
The staff members have mixed emotions about this little gem. A couple feel unhappy they are too mature (read: slightly heavy) to really utilize such a bike. Envy of the smaller people shows in their eyes.
The rest of us really are too mature for (read: afraid of) the tiny rocket. We’ll gladly leave the flying to the younger, more capable pilots.
If you’re caught in the middle, here are two additional incentives: The complete bike may be had without a factory mechanic, and the price adjusted accordingly. Finally, the price of each bike or engine kit includes a genuine DG jersey, and T-shirt, available in father and mother sizes if so desired. 13
SUZUKI
RM8OB
$269.95
