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/126554
... G) .Q E G) ~ c en ~ z ~ ATC SerYlce U Repair ,O-II0-185s-200·250R * Front Suspension All Makes Made to Order Rear Suspension Some Makes * Hellarc Welding Aluminum & Steel * Cyl. Boring $12.00 Per Hole * Trl-Moto 125-175 Mods IMtlS Valt B * . . .taP CA....,. .... (SU)8ft.I'" ~ 16 ~U~ W[J=j]~~~ ....~.,JI[]I".~ ] '-- SANDERS PREDSlON PROClUCT RQ BOX 1BQ3,OEPT. eN GARCEN GAOVE,CA. B2El42 (Top to bottom) Simons 38mm front forks give 10" of trevel. Dirt Werks pipe with built in muffler adds power. Works Performance shock is used. TakIng the Honda 250R a couple of steps further By Eddie Brown Imagine just how great Honda felt knowing their ATe 250R had taken. the three-wheeled market by storm. Their king had everything: the largest, most powerful engine; . a manual clutch five-speed transmission; full suspension front and rear; and enough detailing that you wouldn't lose any sleep worrying about which Hart might fall off next. It was then arid is now the best ATC ever mass-produced. The funny thing is that for some people an otherwise excellent machine compromised for safety and cost reasons just isn't good enough. For Honda, their options were very limited, but it needn't remain that way forever. To get an idea of what can be done to build a very versatile high-performance ATC 250R, let's take a close look at this one fNID Din Werkes. Since the stock front forks aren't the most rigid units to be found, Dirt Werkes opted to use 38mm Simon's with lQ" of ~ravel. With Simon's reputation for excellence, the only question was how to fit fork tubes !l8mm in diameter into 30mm diameter holes. Simons did this by milling out the stock triple clamps and reinforcing the lower holes with steel rings heliarced into place. While it may look marginal. actual testing on an extremely rough whoop-dee-doo track showed this method to handle the stress with room to spare. Fork travel can be lessened by hydralocking (over-filling the fork legs with oil causing the oil to actually be under pressure and stop the fork compression). This allows the 250 to be used over a variety of tracks without needing any disassembly for geometry adjustments. . The rear end sports a series of individual cures which effectively blend together for a very comfortable ride. The most important change is using a Works·Performance shock with its cooling reservoir. This simple bolt-on delivers much increased responsiy~ess and predictability OVP.J' the stocker. The next major change is installing a Dirt Werkes chrome-moly swihgarm, 4\4" longer than stock. With the increased rigidity of the swingarm, and the new shock's longer stroke, the axle now has over eight inches of travel to smooth out even the nastiest of courses. The last change is in widening the rear' wheel track, either by using wheel spacers or a logner chrome-moly Ouralube axle. While accomplishing the same width, the Duralube axle is by far the most reliable way to go considering . how easily axles can be bent. Tire choice varies with Goodyear 21 x 11 8.00 knobbies getting the nod for offroad roosting. As for the powerplant, the only really trick work is in the cylinder porting and milling. Dirt Werkes started out with the basics, first putting on one of their racing pipes with its built-in muffler. These are unique in that the noise level is easily acceptable without the added weight or bulk that comes with other secondary damp-on mufflers.• Next came the installation of a 38mm Mikuni Powerjet carl>· and a special manifold adapter kit. Inside the intake port lives a larger reed block with its fiber reeds. Air filtering is handed by a K & N. All things combined, this motor pulls from the very bottom all the way up, with no habitual clutch or shift lever fanning required. When pulling the one 01' two teeth more on the countershaft sprocket, shott-shifting and third-gear stars were the rule and clutching justified only when photographers are clicking away in search of an awe-inspiring roost. The last few items to go are the stock handlebars and lever operated throttle. In their places are chromemoly Answer Products bars and a Whirlpull straight-pull throttle. If you look closely, you'll see that the throttle pulley is actually below the handlebar level. This positioning decreases the vulnerability of the housing in the event- of an up-side-down endor landing, anq allows the rider's. forearm to protect the cable from snagging should close quarter racing get too enthusiastic. So there it is: the ATC 250R that Honda engineers probably wanted to build before the cost analysts came into the picture. Its balanced approach allows it to be competitive at nearly any type of three-wheeled racing while being committed to none. And when you aren't racing, you can still ride off into the sunset without worrying about how you're going to get back. For more information, you can contact Dirt Werkes at 916/454-5311 or 8141 A Belvedere Avenue, Sacramento, CA 95826. ~