(Above) 2011 KX450F Project Flat Track Bike. (Below) Race Tech suspension works with flat track racing ace Jimmy Wood and has excellent suspension settings for Kawasaki KX450F flat trackers.
People began racing around dirt ovals not long after the first motorcycle hit production. The flat track discipline has been the staple of motorcycling racing and bombing around in circles is where some of the bravest, toughest, and straight up most bad ass racers hail from. In recent years though, flat track racing has not gotten the deserved attention it once had. The AMA has done a good job keeping the national series healthy, with a 22-race series across the United States. But with that, it’s still not like it once was when you could race four or five times a week locally and if you were a professional, earn some extra cash. Fortunately, there are still some awesome promoters and track owners keeping this great sport going. With this in mind, we had no choice but to build a bike, find our balls and go racing.
We decided to convert our 2011 Kawasaki KX450F
into a full-blown flat tracker. When building a flat tracker there are two options, an all-out framer (with a custom aftermarket frame known as a Framer) or you can build a DTX bike (Dirt Track motocrosser). DTX bikes work great and believe it or not only need a few goods and it’s ready to run circles. We opted to build the DTX bike as it’s much easier and less expensive. A modern framer can run as much as $18,000. When everything is said and done, there are a lot of man hours fabricating parts for a framer.
After a few months of thrashing it around the local motocross track in Southern California, we stripped the KX down. Off came the suspension which is without a doubt the most important part of building a flat tracker. You could have big horsepower and it wouldn’t do a thing without a good set-up and correct suspension settings. We opted to go with Race Tech for our suspension needs because they have all the proper settings and work with a lot of high-level racers.
Race Tech lowered the fork height 125mm and installed heavier springs, from a 0.48 to 0.75 kg/mm, along with Race Tech Gold Valves to accommodate. The shock also got the same treatment, lowering it 75mm and adding an 8.5 pound spring along with Race Tech Gold Valves. Overall the bike sits much lower than a stock motocross bike and the suspension is more rigid-feeling. Though you are striving to
(Above) Leo Vince X3 Race Exhaust System replaced the stock set-up. (Below) Excel wheels and Talon hubs are available from Dubya USA (www.dubyausa.com)
have nice controlled slides entering and exiting the corners, it’s all about getting the bike to hook up and drive forward, very reminiscent of settings on a road racer.
Next we ditched the 21-inch front wheel and bolted on some 19-inch wheels front and back. We went with Dubya USA’s trick wheel sets that use a Talon hub front and back, along with Excel rims. Dubya makes a whole slew of color combos and the Talon hub and Excel rim are high-quality products. We used a 19 X 2.15 front rim and a 19 X 2.50 rear rim. The rim size is very important depending on what tires you decide to use, basically the wider the better. We also made a gearing change, mounting up some Renthal sprockets (Renthal 520 Off-Road Front Countershaft Sprocket
and Renthal 520 Off-Road Rear Sprocket
) , removing the 13/50 gearing and installing a 14/48 set-up. Most likely gearing will change from track to track, so it’s a good idea to have a variety of Renthal sprockets on hand.
In the engine department, we left everything stock for this portion of the story. We did, however, bolt on a Leo Vince X3 Race Exhaust System
.This system is super trick and bolted right on with zero hassles. The craftsmanship is incredible, from the beautiful welds down to the trick carbon fiber end cap.
Next we head to the track for some testing and racing…… Stay tuned for Part 2!
Make sure you check out Part 2 of this test where we take the flat tracker to the oval and see how it feels.