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/128222
BikE 2003 OR.O Yamaha YZ450F. DR.Ddoes YZthumpers You can make the DR.D/E..-..-cIlfied VZ450F tum, _ If """re • two-stroke guy. The handling ..k. . _ ........ used to, though. By STEVE COX PHOTOS BY BLAKE CONNER stroke fanatics from turning the throttle while starting the beast. Well, since then, Dubach Racing Development (DR.D) has been coming up with all kinds of interesting pieces - most of which Dubach decided to throw on our test bike. Pretty oug Dubach has been around DYamaha it seems like forever and around the Yamaha thumpers since the program's inception. It almost seems unfair that he develops and sells all of the aftermarket thingamajigs and doohickeys that he does for the machine (unfair for his aftermarket competition, anyway), as he might know more about the YZF MXers than he knows about his own kids - but, then again, it's hard to argue with success. Dubach has been making parts for the blue thumpers for quite a while now; the first part I remember seeing was his hot-start relocation kit for the YZ426F. At that time, the hot-start switch was located on the side of the carburetor, since the bike still had a manual decompression system, so to put the hot start on the handlebar was a huge deal. For the YZ450F, though, Dubach's relocator only moves the unit a couple of feet - from the left side of the bars to the right - which still serves two purposes: First, it frees up your left hand to operate the clutch, and second, it keeps us two- much any time he asked me preferred, deferre t e ecisionmaking back to him. "Hey, Steve, do you want a four- or six-ounce flywheel weight?" he'd say. "I don't know," I'd respond. "Which one do you normally use?" "Usually, I use the four-ounce one." "Then four-ounce it is!" So, Doug started throwing stuff on the bike. He successfully relocated the hot-start lever, dropped in the four-ounce flywheel weight to help tame the potent powerplant, slapped on an hour meter, and then installed his exhaust can. He also provided me with an Applied Racing upper triple clamp to accommodate the Tag Metals T2 oversized bars. The main test of the machine would be at the Glen Helen 6 Hours, so we were under a bit of a deadline to get the bike ready to race by then. The last thing he personally installed was his brand-new, hot-off- 38 n JULY 9,2003' cue I e wha~t~I_~.....~::!!~:J~~=::::!~~~:::=-j~~~==::~"~=5~~==:~~! e vw s the-presses Honda-routing frontbrake-line clamp. This was maybe the trickest part of the bunch. He now sells it as part of a kit, including his own line of front-brake lines, but when I got it on the Cycle News test bike, it was just a lonely piece of billet. The stock Yamaha front-brake line goes down along the left fork leg and secures itself to the fork by clamping to and wrapping around the bottom of the leg. How Dubach's system is different is that the aluminum piece rivets onto the top of the left fork guard and then utilizes one of the two clamps al)d bolts that are no longer needed at the bottom of the fork leg to clamp the new brake line to the guard. This way, you can run a shorter, more direct brake route, similar to the Honda CR line, and get better front-brake feel and performance. There are a lot of different front- brake rerouting kits out there, but DR. D's is probably the simplest and most ingenious of all of them as far as YZs are concerned. Most of the other kits require you to safety-wire parts of the brake line in order to make sure it holds together, but the DR.D unit holds the line so securely that the extra wiring isn't needed. With the front-brake unit, Dubach installed the front-brake line off of one of his bikes (saving us the time of bleeding the system), which included an ARC adjustable, folding front-brake lever. ARC levers fold out of the way in crashes with a springloaded hinge, which keeps them from bending in almost any situation. The coolest thing about these levers in my opinion is the adjustability. The 2003 450 doesn't exactly have an easy clutch pull, so after I installed the matching ARC clutch lever, I was