Factory Bike Friday: JGR YZ450F
The Non-Factory Works Bike
Factory Bike Friday: Stewart’s Non-Factory Works Bike
Type-Os and Photos: Scott Hoffman
Take a half cup of NASCAR team, one quarter cup Factory Yamaha, one cup aftermarket accessories, and a crew of amazing mechanics and engineers to create Team JGR (Joe Gibbs Racing). For 2012, JGR has upped the game with not only hooking up with James Stewart, but also further advancing their race bikes. Stewart’s YZ450F is one of the most unique machines in the pits with an assemblage of JGR technology, Factory Yamaha parts, and aftermarket accessories. While Davi Millsaps’ and Stewart’s bike share many parts, Stewart’s machine has a few specialty components such as the fuel tank and radiator shrouds built especially for his riding style.
James Stewart's race bike is one of most trick bikes in the pits with all sorts of electronics, data acquisition, and unique performance components. I wonder if the data acquisition software talks back to you like an iPhone 4s: “Yes James, I have found 7 places you have hit the ground this year, many very close to this location.”
The shocks are designed and built by one of JGR's NASCAR shock builders. Also notice the O2 oxygen sensor tucked behind the frame. This is either for data collection or auto tuning while on the track.
The engine components are fancy in his ride—Yamaha factory transmission and possibly crank, Hinson clutch, CNC ported head, Factory Valve components and JE Piston.
The linkage is unmarked and could be an SDI unit or custom-made component from JGR or Yamaha.
Special rear axle with SDI wheel blocks.
CNC-machined master cylinder cover.
Stewart runs what looks like an XTrig rubber bar mount.
Custom FMF exhaust, yet we hear this cap may be available in a special JGR edition.
The team runs Kite wheels through Dubya USA.
There is a slew of electronics hooked into Stewart's ride via GET. We even saw the team waiting for a light to show that indicated the engine was up to operating temp or if it were too warm on the start line.
The fuel tank is a mix of billet aluminum and sheet aluminum assembled together. The tank alone is worth thousands of dollars.
Remarkably, a rather production-looking front brake caliper is affixed to an oversized brake bracket. And because JGR runs a Showa fork, the team had to machine special fork bottoms to accommodate a Yamaha front wheel.
Special radiator shrouds were built to accommodate the narrow fuel tank and radiators to suit Stewart's forward riding style.