— Built by Lonestar Racing to win! — 

By the staff of Dirt Wheels

Andrea Henderson has been competing against men in the National Hare & Hound series on this LoneStar Racing Honda TRX250R for 15 years. This is the latest reinvention of this potent racer.

We’ve seen a large number of ATV enthusiasts rebuilding the beloved Honda TRX250R to its former glory. Retro is in right now, and the TRX250R is over 30 years old, so it’s retro for real. For the last decade most TRX250R projects we’ve seen were play machines, but now many riders have started building them to race against modern machinery.

The Bosemer family never stopped living the two-stroke lifestyle. You may recall that we featured Rachel Bosemer’s desert championship-winning LSR TRX250R and her father Rick Bosemer’s Yamaha Banshee in past issues. We are back with eldest sister Andrea Bosemer-Henderson’s LSR TRX250R. It went under the knife after over a decade of desert racing. This machine brought her an AMA National Hare and Hound championship against the men and many race wins, but it was due for some much-needed love. Luckily, her father Rick and his friend and fellow desert racer Eric Pealstrom were ready to rebuild it better than it was before. They got it done for her as a Christmas present. Somebody was a good girl!

GPR steering stabilizers are a hit with desert racers. For a light quad like Henderson’s, the GPR adds a major level of control to the front end.


This quad is constantly put through races across California, Utah and Nevada deserts. Andrea follows the National Hare and Hound series, competes in local Southern California District 37 desert races and rides anything else that her schedule allows. She pushes her 250R to the limit, whether it’s a single-track rock section or a 70-mph dry lake bed. A stock 250R would leave you hesitating or worried about the speed, but this 250R leaves you secure. Fasst Company’s Flexx handlebar plays a big part in the comfort of riding this quad, as it offers comfort, control and top-notch ergonomics. The best part of the Flexx handlebar is the vibration reduction. Anyone who has ridden a two-stroke knows of the increased vibration in comparison to four-strokes.

The handlebar is mounted on a Lonestar anti-vibration steering stem. It is made from chromoly, which greatly increases its strength and durability even after the toughest tests. This steering stem put the handlebars at the perfect height. Andrea’s quad is equipped with a GPR V1 steering stabilizer. The stabilizer is user-friendly with only one knob adjustment, and it was mounted below the handlebars to ease access for on-the-go adjustments. The stabilizer works great. It absorbed cross-grained ruts rather than allowing the handlebar to be ripped out of your hands. A Works Connection lever/perch assembly was a welcome add-on. Just the bearing that WC uses on their lever creates an even clutch pull feeling every time. Any aspiring desert racer needs a good set of hand-guards. Cycra Racing Rebound handguards offer great hand protection while blasting through pucker bushes or tall sage brush. Cycra Rebound guards rotate forward in the result of a crash.

Henderson’s TRX250R looks a bit unique jumping with tall desert tires mounted up. In spite of the look, this is one well-refined race quad that really can do just about anything


Every racer’s focus is on protecting their quad baby to finish grueling races with no problems. That is why Campbell Racing Fabrication’s plastic skid plates were included in the build. Unlike aluminum skid plates, these plastic skid plates glide over the sharpest rocks with ease and lessen your chance of getting hung up. To protect the new LSR swingarm, a 0.190-inch-thick PRM aluminum skid plate was mounted. These are possibly the strongest options available on the market. They are made with less welding, and that creates a strong piece of aluminum. The one they removed had six years of racing on it, and though it was beat up, it could’ve survived a few more years.

Andrea’s quad got a pair of new shoes with ITP Holeshot XCT tires and ITP A6 Trac-Lock wheels. These bead-lock wheels and six-ply tires are awesome for desert racing. The front tires help the quad track well in silt beds since they don’t have a lot of side bite. Within these already amazing tires are a set of Tire Blocks. Tire Blocks allowed us to blow through rocks, bushes  and anything else we could find without even thinking about getting a flat. Even if you pierce a tire, you will not notice it until you’re off the quad.

Boyko Racing built the motor. It is ported and has a Pro Design head, a V-Force reed cage, and an FMF pipe and silencer.

This eye-catching quad is outfitted with a brand-new set of Maier electric blue front and rear fenders and is topped off with a black Maier Smoothy hood. A high-quality Spider Graphix graphics kit adorns these bright plastics. The graphics, as well as the rest of the quad, was a Christmas surprise specially designed by her family for Andrea’s racing comeback.

These graphics include all of the colors and designs that a girl could ever want on her desert-dominating machine. The graphics are easy to install and will last ride after ride. Andrea’s quad features an oversize IMS desert fuel tank. This tank fits seamlessly with the Maier plastics and allows long-distance rides and races to be completed without a pit stop. A taller seat fitted with desert foam and wrapped in a custom Moto Seat cover pulls together the graphics, plastics and overall look of this 250R.

Adding a modern touch to this 250R was as easy as calling Rath Racing. A Rath aluminum front bumper has great lifting points when getting hung up in rock sections, and Rath’s aluminum nerf bars with their stainless steel pegs gave Andrea’s feet much-needed traction.

The PEP shocks have endured many years of racing but were just fully serviced in preparation for the new season. The wide A-arms are LoneStar Racing and the front bumper is a Rath Racing unit.


Andrea’s 250R has dominated the California desert race scene, and much of that success is thanks to the top-of-the-line components it was built with. Her quad was built with a Lonestar Racing frame, which allows the quad better ground clearance, strength and overall geometry than the stock 250R frame. Lonestar A-arms are also on this build, increasing the quad’s ability to easily get through tough Lucerne Valley rock sections. Quality Lonestar products continue with the use of a Lonestar axle, which increased the quad’s width, durability and overall strength. The width is 2 inches wider and 1 inch forward than the stock 250R; this helps increase the rider’s ability to make tight turns and offers greater stability.

The quad’s original PEP ZPS shocks were rebuilt by Baldwin Motorsports. The shocks allow the quad to glide through the desert’s tough ruts and whoops with ease. The shocks originally felt stiff but were easily dialed with a few minor adjustments and some test rides through the whoops. These shocks have gone through 15 years of pounding, and they are just as great as the first time they were used. The rear of the quad is equipped with a Lonestar no-link swingarm, preventing the worrisome replacement of a shock clevis or linkage.

These tall desert seats aren’t really the current style, but neither is a Honda TRX250R two-stroke racer. The seat makes standing up easy.


Rick has always relied on Boyko Racing to build two-stroke engines, and Teddy Boyko knows two-strokes. The engine has a few over-bores, but it still remains under 260cc. Teddy hand-ported the cylinder, bored it and put in a fresh top-end to freshen things up. A Hot Rods full bottom-end kit comes with everything needed in one kit. A Pro Design cool head has kept this engine cool for over 15 years, and it’s still doing its job. A V-Force 3 reed cage and a 38mm Keihin Air-Striker carburetor fuel this beast.

There is no “vintage bike” feel to the clutch. It has Hinson internals and a Works Connection billet perch and lever. This is a great clutch setup that has good feel, great performance and a light lever pull.

For a mild engine, we were really impressed with the power it makes. We mistakenly thought we would be clutching this machine to stay on the pipe. It had plenty of low-end power thanks to the Boyko porting and the Supersprox gearing. Once in the powerband, we could grab gear after gear, and it would quickly climb to the rpm limit all the way through sixth gear. The Hinson clutch is very smooth, and it was easy to disengage with the help of the Works Connection lever. The FMF Fatty exhaust and Turbine Core 2 spark arrestor/silencer were icing on the cake.


The Bosemer family has the right combination of know-how to make these retro machines win races. The day following the test, Andrea was able to race it at the first round of the 2018 National Hare and Hound series. She ended up winning the men’s Expert class and taking third overall, beating some fast pro riders. This just goes to show you that legends really never die, especially the mighty 250R!

Tall ITP Holeshot tires and wheels, a desert seat, steering damper, and a Fasst Co. Flexx handlebar all refine the LSR frame and no-linkage swingarm. The custom aluminum grab-bar toolbox is a family tradition.


Fasst Company:, (877) 306-1801

Flexx handlebars $359.99

Rath Racing:, (320) 234-7223

TRX aluminum bumper $124.95

Competition aluminum nerf bars (custom) $464.95

Rocky Mountain ATV/MC:, (800) 336-5437

Tusk sintered metal  front brake pads $16.99 per side

Tusk sintered metal  rear brake pads $16.99

Tusk +2-inch front  steel-braided brake lines $69.99

Tusk rear steel-braided brake line $29.99

Tusk master cylinder top cover $19.99

Hot Rods:, (515) 402-8000

Complete standard bottom end rebuild kit $411.95

Supersprox USA:, (800) 328-5454

Steel front sprocket $19.95

Steel 36-tooth rear sprocket $39.95

Cycra Racing:, (800) 770-2259

Rebound handguards racer pack $79.95

Pro Design:, (714) 534-0620

TRX250R cylinder head $199.95

Moto Tassinari:, (603) 298-6646

VForce3 reed system $158

LoneStar Racing:, (800) 457-7223

A-arms sport style, +2 wide, +1 forward $650

+2 +1 chromoly anti-vibe steering stem with clamp $362

No-link swingarm $749

Billet-axle bearing carrier $199

Axcaliber axle $449

TM Designworks:, (541) 772-4161

TRX250R Slide-N-Guide kit $129.95

Campbell Racing Fabrication:, (435) 632-4902

1/2-inch plastic skid plate $110

TireBlocks:, (253) 973-5111

23x7x10 TireBlocks ront tire kit $135 per tire

22x10x9 TireBlocks rear tire kit $142.50 per tire

ITP Tires:, (909) 390-1905

23x7x10 Holeshot XCT front tire $144.64 per tire

22x10x9 Holeshot XCT rear tire $188.70 per tire

10×5-inch A-6 Trac-Lock front wheel $235.95 per wheel

9×8-inch A-6 Trac-Lock rear wheel $243.95 per wheel

Boyko Racing:, (949) 642-3275

Porting: Price varies Cylinder bore service Price varies

Maier Mfg.:, (800) 33-MAIER

Smoothy front hood $76.28

TRX250R front fender kit $353.35

TRX250R rear fender $297.07

FMF Racing:, (310) 631-4363

Fatty exhaust $279.99

Turbinecore 2 silencer $169.99

Spider Graphix:, (317) 996-5555

Custom graphic kit Price varies

GPR Stabilizer:, (619) 661-0101

Steering stabilizer kit $525

Moto Seat:, (951) 677-8325

Ribbed traction seat cover $69.95

Hinson Racing:, (909) 946-2942

Billetproof clutch basket $259.99

FSC Works Style 7 plate clutch and spring kit $199.99

IMS Products:, (800) 237-9906

4.0-gallon fuel tank $274.95

All Balls Racing:

Carburetor rebuild kit $32.95

Clutch cable $11.50

Throttle cable $22.95

Pivot Works:, (515) 402-8000

Front wheel bearing kit $29.95 per side

Swingarm bearing kit $49.95

Works Connection:, (530) 642-9488

Elite clutch perch assembly/Honda lever $155.85

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