MotoUSA EnduroCross Bike Build

November 16, 2006
JC Hilderbrand
JC Hilderbrand
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Hilde is holding down the fort at MotoUSA's Southern Oregon HQ. With world-class dirt bike and ATV trails just minutes away, the hardest part is getting him to focus on the keyboard. Two wheels or four, it doesn't matter to our Off-Road Editor so long as it goes like hell in the dirt.

David Knight is the reigning champion of EnduroCross - and we want a piece of him! Actually  we just want to qualify for the Saturday program  then we ll talk about Knighter. For the first time MotoUSA will compete at the extreme off-road race held in The Orleans Arena in Las Vegas  NV.
David Knight is the reigning champion of EnduroCross – and we want a piece of him! Actually, we just want to qualify for the Saturday program, then we’ll talk about Knighter. For the first time MotoUSA will compete at the extreme off-road race held in The Orleans Arena in Las Vegas, NV.

EnduroCross – The concept of bringing an off-road race into a stadium for maximum spectator viewing has caught on quickly in the US since the promoters first attempted the event in 2004. In its third year at The Orleans in Las Vegas, NV, EnduroX has drawn the top competitors’ names in the off-road world and is pre-sold out as fans flock to the gambling center of America to watch this relatively new form of extreme off-roading. Every type of obstacle normally encountered in the woods, and a few man-made obstacles, will be placed on the stadium floor: rock piles, log-crossings, water holes, heavy equipment tires and ruts. After watching the intense action and brutal carnage that has been the norm since Day 1 at this event, MotoUSA has decided to give it a try.

Event promoter, Tim Clark, extended an invitation to our Creative Director, Brian Chamberlain a couple months ago to join the ranks of off-road hopefuls that weren’t included on the invited riders list. These regular Joes (or Brians) are competing on Friday in one or more of five available classes: Junior Class, Open 2-Stroke, Open 4-Stoke, Vet +35 and EX Qualifier. A complicated qualifying process, which you can see at, will make it difficult to reach Saturday’s qualifying program to say the least. Our guy will contest the 4-Stroke Open and EX Qualifier in his bid for a spot on the Main Event Saturday night and a shot at the $20,000 purse.

Faced with the challenge of arranging a loaner bike on short notice, Brian elected to sacrifice his own machine for the project. His 2004 CRF450R was in need of a few upgrades so he took the event as an opportunity to validate the expenses to his wife. Knowing that he will be facing the likes of ’05 champ David Knight, motocross hero John Dowd and AMA Hare and Hound champion Destry Abbott, among others, BC knew he’d have plenty to explain when balancing the checkbook.

We’ve spent the weeks since gathering parts from various sources of aid. Some were donated by generous (sympathetic?) companies, some were stolen from other machines in our garage and others were bought outright. All told, here’s the fast and ugly on our EnduroCross Project Build.

Taming the Beast

The first chore in our motor modification was to yank this baby.
A little extra weight can be a good thing. The 13-oz. Steahly Off Road flywheel we installed should help avoid stalling that big 4-stroke in the tight arena and give plenty of bottom-end traction.

Since lots of riders start building their off-road weapon for this race from a bone stock 2-stroke motocrosser, we felt that the moto-specific 450R sitting in out garage would be a solid platform to build from. We do know, however, that if we intend to stay on the stadium floor and not go launching into the top-dollar, front-row seats, controlling the abrupt motor is a high priority. BC has been riding his bike for a couple years now, primarily in the woods. His comfort level with the hard-hitting delivery is a result of his ability to yank the front end over obstacles at the mere inkling of thought. Not wanting to completely eradicate that sensation, we decided to leave the heavy enduro-izing to nothing more than an additional flywheel weight.

Steahly Off Road is considered an industry leader in this arena and it just so happens that the shop is right down the street from our offices. We swung by one afternoon and had owner Chuck Steahly guide us through a 13-ounce installation. Steahly’s know-how and a little additional filing of the inner ignition cover had the bulkier flywheel mounted up in no time. Some initial testing has proven that the weight does allow the motor to chug down further in the rpm range without stalling, but Chamberlain is still getting used to the effects of the new hardware.

“It really enables me to lug the bike down more, almost to a stop,” says BC. “I thought it would reduce stalling but I’m still having a little trouble with that in the really tight stuff. I think I’m just not used to it yet. It also tones down the motor so it doesn’t have that crazy hit anymore and it’s a lot more manageable.”

BC is betting the house that his setup will be an improvement over his regular 19-inch wheel tire combo.
BC is betting the house that his setup will be an improvement over his regular 19-inch wheel/tire combo.

One of Brian’s strongest attributes is his ability to jerk the front end over obstacles with a twist of the wrist. Concern that the heavier flywheel might counteract that affect led to a gearing change that bumped the rear sprocket up one tooth to a 49. The extra grunt will help clear obstructions directly out of corners. The sweet, black anodized aluminum is not only lighter and stronger but matches well with a new set of black Pro Wheel rims.

The reasoning behind purchasing a whole new set of wheels was to have an 18-inch rim on the back to accept enduro-style tires – more exactly a trials tire. Trials tires have been all the rage with extreme off-roading in the past couple years so we made a running leap on to the bandwagon in our first bid for EnduroCross glory. Our hope is that the super-soft compound will get superior traction on the gnarly stuff and help reign in the hard-hitting power of our project bike.

The Dunlop D803 Trials tire we spooned carefully on to that shiny, black rim is the same rubber Geoff Aaron used to win the 2005 National Trials Championship, one of his 10. As it turned out, the balancing extraordinaire had a little more trouble at the ’05 EnduroCross. Instead of claiming the title, Aaron failed to even make the main with stiff competition and an even tougher course. Dunlop boasts that the tire is great for trail riding which we’re hoping it is with the fast straight and tight corners composed of dirt rather than the more common logs, rocks and tires.

Once it’s all put together the Works Connection Holeshot Device is a clean  simple addition to your bike. We’re hoping that it helps get us into the first corner a bit faster than usual.
Once it’s all put together the Works Connection Holeshot Device is a clean, simple addition to your bike. We’re hoping that it helps get us into the first corner a bit faster than usual.

One area of the race where we’ll need all the power available from that CRF is at the start. Getting to the first corner in a good position will be crucial to a successful outing. Having to fight through the pack and finding alternate lines around downed riders can be tough in such cramped quarters. To help keep the front wheel down off the gate and headed to the front of the pack, we bolted on a Works Connection Holeshot Device. Common at any off-road, SX, MX, AX or other event that utilizes gate starts, the WC unit was a no-brainer.

“It makes sense to compress the front end like that,” says Chamberlain. “It seems like a pretty simple device to achieve a better start. I don’t think it’s going to overcome a major error but it’ll definitely help keep the front end down. I’m glad it’s on there. If anything it’s a psychological advantage to have one.”

Survival of the Fittest

The first thing that came to mind when thinking about riding at EnduroCross was that damn rock pile. BC’s poor, unprotected 450 was in for a rough time in its painfully stock condition so our initial priority was to beef up the armor to keep those case-cracking boulders at bay. Works Connection again offered their assistance by replacing the flimsy, plastic engine guards with a stout set of aluminum protectors. A skidplate also adds invaluable security for the soft underbelly which originally has nothing to stop a weekend-ruining collision.

“I’d say the thing I’m most stoked about are the skidplate and engine guards since the 4-stroke is a little more susceptible to damage,” BC says.

Two screws and four bolts – installation doesn’t get much easier than on the Works Connection skidplate.
Works Connection was quick to jump on board. They love proving that their products work so we wound up with this skidplate/engine guard combo. Two screws and four bolts – installation doesn’t get much easier than on the Works Connection skidplate.

Additional armor was strapped on as well in the form of a few MotoUSA standards. ASV unbreakable levers adorn both sides of the Renthal Twinwall handlebars and are covered by the uber-tough Acerbis Multiplo aluminum handguards. Anyone who thinks they are going to get through a full day of EnduroCross racing without crashing is either amazingly confident or blindingly ignorant. Two days would be an act of god. The protection is mainly to prevent as much crash damage as possible and whatever isn’t covered falls under the J-B Weld umbrella.

Another small addition that makes a big difference is a set of Tag Oversized Bar Mounts with a 10mm rise. The extra height makes standing easier for our 6-foot rider who will undoubtedly be standing for the majority of the course. A dab of glue and twist of wire secure the fresh set of badass Renthal Kevlar grips to ensure maximum control. Even though it wasn’t necessary for performance gains, TSS Graphics sent us a one-off MotoUSA/EnduroX decal package. The sweet deal gave us an upscale look that will turn heads in the pits regardless of our results.

Will it be enough? That is the ultimate question. Our hopes lie not only in the bike preparation but in the capabilities of our rider. Though Brian’s training regimen has been targeted by occasional criticism, we’ll be sure to point out whether or not he is up to par. Making fun of our good-natured comrade is almost as much fun as celebrating a successful outing. Either way, MotoUSA is finally taking more than a sponsorship role in the wildly popular EnduroCross. Stay tuned for results, not only of our efforts but of the competition as well.

2006 EnduroCross Project Build
This is it. This is what we have to work with. Wish us luck and we’ll see you in Vegas. Keep your eyes open on Friday and root for the jersey with BC74.

2004 CRF450R EnduroCross Project Build:
Acerbis Multiplo Handguards
ASV Unbreakable Clutch w/Hot Start
ASV F3 Front Brake Lever
Pro Wheels 21″ Front
Pro Wheels 18″ Rear
Dunlop 739 Front Tire
Dunlop 803 Trials Rear Tire
Fly Racing HD Tubes
Works Connection Radiator Braces
Works Connection Holeshot Device
Works Connection Skidplate/Engine Guards
Steahly 13oz. Flywheel Weight
Renthal Twinwall Handlebars
Renthal 49T Anodized Sprocket
Renthal Works Chain
Renthal Kevlar Grips
Tag 10mm-rise Oversized Bar Mounts
Ceet Gripper Seat Cover
TSS Custom Graphics
White Brothers E2 Silencer

Talk about our stab at tackling the EnduroCross in the forum.

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