PROJECT ATV: HONDA TRX250R

A legendary quad still winning AMA national championships 
By the staff of Dirt Wheels

One thing that the 250R is well known for is handling. Even though this bike sits taller with the CEET Desert seat, you can still throw this thing sideways. It stays planted with the Maxxis tires biting and the Hinson clutch keeping the momentum forward.
One thing that the 250R is well known for is handling. Even though this bike sits taller with the CEET Desert seat, you can still throw this thing sideways. It stays planted with the Maxxis tires biting and the Hinson clutch keeping the momentum forward.

 

In the late ’80s, manufacturers were looking for alternatives to the popular but much-criticized three-wheelers that dominated the ATV market. Suzuki had the answer: four-wheelers. The most famous being the high-performance two-stroke LT250 and LT500 (Quadzilla), Yamaha had the Banshee, Kawasaki produced the Tecate 250, and then it was Honda’s turn. With the TRX250R, Honda leveraged years of three-wheeler excellence into a sport quad with great styling, great suspension and a great chassis. The combination made the Honda TRX250R one of the most iconic ATV race machines ever built. From 1986 until 2004, when the high-performance world of the four-stroke came to the forefront for the ATV racing world, the TRX250R reigned as the winningest ATV ever conceived.

Mixing old technology with new technology: The 250R shines with these modern Elka Stage 5 shocks to create a plush ride! The GPR Version 1 stabilizer helps with the bump-steer, which helps keep the control in your hands.
Mixing old technology with new technology: The 250R shines with these modern Elka Stage 5 shocks to create a plush ride! The GPR Version 1 stabilizer helps with the bump-steer, which helps keep the control in your hands.

 

Most people are racing four-strokes these days, but with companies pulling back their production sport models, we have been seeing a lot more people resurrecting the legendary TRX250R! Two-time AMA National Hare & Hound A-class champion Rachel Bosemer is one of those racers. The difference is that Rachel never switched to a four-stroke. Her father isn’t a four-stroke fan. He races the National Hare & Hound series on a Banshee, while Rachel’s sister, Andrea, also races a TRX250R. It’s a two-stroke family affair of premix goodness! The best part about Rachel’s racing is that the AMA National Hare & Hound series does not offer a women’s class, so that leaves her racing against the men. Obviously, with two AMA championships under her belt, the men have their work cut out for them when the TRX250R comes to life!

Lonestar Racing +2-wide and +1-forward A-arms help with the stability up front, while a Lonestar-adjustable race axle helps with keeping the rear end wider for great handling.
Lonestar Racing +2-wide and +1-forward A-arms help with the stability up front, while a Lonestar-adjustable race axle helps with keeping the rear end wider for great handling.

 

HANDLING

Rachel’s quad is not your standard out-of-the-crate TRX250R. It is fully modified with few stock parts. Since desert racing is tough on the machines, they built this thing to last. It has a Lonestar Racing frame, which has better geometry than a stock frame and also offers the quad more ground clearance. Premium Elka Stage 5 shocks are a recent addition that raised the TRX’s game in the rough. The Honda glides over the toughest obstacles, especially the rockier sections where Rachel shows the men in her class how it is done! The modern Elka shocks were a much-needed upgrade that complemented the already great feel of the quad. The quad has chrome Lonestar A-arms installed for great handling and good ground clearance. At the rear of the quad is an Elka Stage 5 shock mounted to a standard-length chrome Lonestar No-Link swingarm. With the No-Link swingarm, Rachel doesn’t worry about ruining a shock clevis or linkage! The rear of the quad performs just as well as the front. A Lonestar axle was added for strength, the ability to widen the track and its durability. With the axle and A-arms, the quad’s width is 2 inches wider and 1 inch longer than the stock TRX250R. Having a wider and longer quad helps with stability when making abrupt turns and getting it straightened back out when it wants to yard sale! It is still great for the tight singletrack that NHHA (National Hare & Hound Association) ATV riders find themselves in.

Flexx handlebars are a great addition for racers and weekend warriors alike! They provide suspension for your upper body. They also reduce rider fatigue, blisters and help with dreaded arm pump! Fastway Flak handguards are installed for protecting the hands, while Spider Grips keep them planted.
Flexx handlebars are a great addition for racers and weekend warriors alike! They provide suspension for your upper body. They also reduce rider fatigue, blisters and help with dreaded arm pump! Fastway Flak handguards are installed for protecting the hands, while Spider Grips keep them planted.

 

CONTROL

When reaching speeds well into the 70-mph-plus range, you need the most control you can possibly get. Fasst Company’s Flexx handlebars offer amazing comfort, control and ergonomics. Rachel relies on the shock-absorbing features of the Flexx handlebars to help her stay in control and keep her upper body safe from unexpected G-outs. An added benefit is that the Flexx handlebars help reduce the vibration. This is a great feature, since two-strokes typically vibrate more than four-strokes. She prefers the softest elastomer setup (blue compression, yellow rebound) for desert racing. To complement the handlebar is a chrome Roll Design anti-vibration stem that further reduces high-frequency vibration and is stronger than the OEM stem.

FMF is known for their awesome exhausts. This Fatty expansion chamber has the looks, power and sound that we all love.
FMF is known for their awesome exhausts. This Fatty expansion chamber has the looks, power and sound that we all love.

 

Sport quads in general have a lot of bump-steer. Rachel’s quad does not because of the use of a GPR V1 steering stabilizer. This stabilizer offers only one adjustment knob, but it works great for what we experienced out on the trail. A Works Connection Elite perch and lever system was installed to give it a smoother clutch pull and the best possible leverage for clutch actuation. Also, Fastway has some slick bolt-on handguards called Flak handguards. These lightweight handguards offer great protection from the rocks, trees and shrubs you will come across in the desert.

The custom rear box/grab bar is a nice addition that carries a radio, rope and spark plugs for insurance. The FMF Turbinecore sounds great, even with the spark arrestor that is needed for desert racing.
The custom rear box/grab bar is a nice addition that carries a radio, rope and spark plugs for insurance. The FMF Turbinecore sounds great, even with the spark arrestor that is needed for desert racing.

 

For any type of riding, you will want to make sure that your grips are going to be comfortable for your hands. Spider grips work fantastic for Rachel’s small hands. They offer a very comfortable ride while keeping her hands planted. A Pro Design tether kill switch was installed, as it is required when competing in most racing organizations. Standard OEM brake pads stop this beast. The Bosemers believe they are the best, and once we rode it, we could see why! This thing can stop on a dime!

The swingarm is a Lonestar No-Link setup, so the crucial parts of the Elka shock won’t get damaged in the desert terrain. A PRP swingarm skid plate keeps the chain and rear brake rotor protected.
The swingarm is a Lonestar No-Link setup, so the crucial parts of the Elka shock won’t get damaged in the desert terrain. A PRP swingarm skid plate keeps the chain and rear brake rotor protected.

 

PERFORMANCE

Boyko Racing handles the internal engine mods with a race-style ported and polished cylinder. This is not one of the popular big bores, but an actual 250 with a Boyko-modified 38mm Keihin carburetor, a Pro Design Cool Head (for lower operating temperatures and more horsepower) and a Wossner piston. A VForce 3 reed valve complements this engine package, helping the throttle response and driveability. With the fine dust and sand in desert racing, Rachel relies on Uni air filters to keep her critical engine parts protected while increasing airflow.

The Full Bore plastic looks great with the custom Spider Graphix installed. It’s always nice to win races, but you need to look good doing it as well!
The Full Bore plastic looks great with the custom Spider Graphix installed. It’s always nice to win races, but you need to look good doing it as well!

 

Her father custom-made an aluminum airbox that sits higher for clearance in the rare case that Rachel would bottom out the rear suspension. The Hinson billet-proof Works clutch basket was installed with Hinson’s fiber and steel clutch plates and Hinson springs. The TRX250R tracked well and had a very smooth clutch feel, as it provided traction for any uphill we ripped up. An engine package would not be complete without a great exhaust. Rachel has run FMF since she started racing on this bad boy. The Fatty pipe along with the TurbineCore 2 spark arrestor makes a great power combo with a fantastic sound. Most desert-racing associations require spark arrestors for competition.

Maxxis Razr tires are loved by many desert racers. They provide killer traction in multiple course conditions. The Bosemers also had custom-reinforced rings welded onto the wheels for strength.
Maxxis Razr tires are loved by many desert racers. They provide killer traction in multiple course conditions. The Bosemers also had custom-reinforced rings welded onto the wheels for strength.

 

PROTECTION, WHEELS, TIRES & STYLE! 

Every desert racer needs to protect the vital parts of their quads from the gnarly rocks, roots, bushes and other sundry hazards in the desert. Underneath this TRX250R are custom aluminum skid plates for the chassis. This includes A-arm skid plates, a frame skid plate and a PRM swing-arm skid plate. Tusk Pro Peg nerf bars are installed, and they provide great boot traction via the stainless steel footpegs.

Rachel relies on custom aluminum skid plates to keep the chassis components intact, while a Rath Signature-series bumper protects the front end. As you can see, the skid plates have done their job nicely through the years!
Rachel relies on custom aluminum skid plates to keep the chassis components intact, while a Rath Signature-series bumper protects the front end. As you can see, the skid plates have done their job nicely through the years!

 

Maxxis Tires, one of Rachel’s new sponsors, makes a great setup for the desert. The wheels on this machine are a little custom. They’re standard DWT Red Labels in the front, with a reinforced aluminum ring welded in for strength. The rear wheels are ITP with the same reinforced rings as the front. Desert racers always need more ground clearance. Rachel prefers the Maxxis Razr front in 23×7-10 and the Razr rear in 22×11-9. These tires offer great traction in any situation, and despite massive sharp-edged rocks, we finished the day off with no flats!

Spider Graphix came on this season as a new sponsor for Rachel as well. She helped Austin (owner of Spider Graphix) design unique, one-off graphics that scream custom! We love the styling, and we were also able to observe the installation of these graphics. Spider Graphix uses a high-quality material to ensure that their kits will not come off in high-speed sections or be affected by the elements. Overall, the Spider Graphix kit was a breeze to install.

Since desert races are longer races, sometimes without pit stops, Rachel needed an oversized IMS fuel tank. The tank sits pretty high on the TRX250R, so running a taller stem or risers to prevent your handlebars from hitting the tank may be required. Rachel also prefers a taller seat with a gripper seat cover from CEET, which is very comfortable on those longer jaunts through the desert.

THOUGHTS ON A LEGEND

Rachel is known for her national championships against the men in the A-class. This amazing machine has a lot to do with her winning those championships. It has great power for a smaller-bore two-stroke and handled anything we threw at it. We were also stoked on how light the quad felt. Whether we were pitching it into the corners or getting it airborne in the deep whoops, it is a blast to ride! If you are looking to get into competitive racing or just looking to show your four-stroke buddies how it’s done, we suggest looking into purchasing a Honda TRX250R!

HALFPAGE_250R

 

RIDER/SPONSORS

Owner/rider Rachel Bosemer
Bike builder Rick Bosemer
Contributors…Accelerated Funding, AMSOIL/Scottsoil.com, Fasst Company/Flexx Handlebars, Maxxis Tires, Fly Racing, Spider Graphix, Hinson Racing, Boyko Racing, Elka Suspension

MACHINE
1987 Honda TRX250R with 2002 Lonestar Frame

MOTOR
Boyko Racing port/polish Price varies
Wossner piston $149.99
Keihin 38MM carburetor with Boyko Racing carb service Price varies
Custom aluminum air box/Uni filter $29.99
FMF Fatty pipe w/ FMF TurbineCore 2 spark arrestor $429.98
110 Race fuel $8 a gallon Amsoil Dominator 2 premix $11/qt

DRIVE SYSTEM
Hinson Works clutch basket $249.99
Hinson fibers, steels and spring kit (FSC lit) $199.99
Amsoil 10W40 $11/qt
Amsoil chain lube $10
Vortex front and rear sprockets $43
Primary Drive X-ring chain $59.71

FRONT END
Lonestar A-arms +2-+1 forward $675
Elka Stage 5 front shocks $1,700
Roll Design steering stem $299.95
GPR V1 steering stabilizer $525

REAR END
Lonestar No-Link stock-length swingarm $675
Lonestar +2 rear axle/carrier $449/$185
Elka Stage 5 rear shock $1300

TIRES/WHEELS/HUBS
Maxxis Razr 6-ply 23X7-10 front tires $264
Maxxis Razr 6-ply 22X11-9 rear tires $380
DWT 10-inch front wheels with custom reinforced rings $150/pair
ITP 9-inch rears w/ custom reinforced rings $172

BRAKES
American Star brake lines $70 (f)/$30 (r)
Amsoil brake fluid N/A

HANDLEBARS/CONTROLS
Fasst Co./Flexx handlebars, 15-deg. Quad Racer bend $359.99
Fastway Flak handguards $49.99
Works Connection Elite clutch perch/lever $195.85

MISCELLANEOUS
Tusk Pro Peg nerf bars $179.99
Rath Racing Signature-series bumper $124.95
Custom aluminum box/grab bar N/A
Custom aluminum skid plates N/A
CEET Desert seat N/A
IMS oversized tank $274.95
Full Bore plastic bodywork N/A

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