The beauty of the aftermarket is that you don’t have to start with a brand new motorcycle to end up with a pulse-pounding ride, and Dave Schmidt’s 2004 KTM 450 EXC dual sporter stands as a perfect example of what can be done when you start with a quality model as the foundation for a project bike.
Schmidt is the proprietor of Schmidt Performance, a Southern California-based business that has been around since 1998. Schmidt has over 18 years of experience working on suspension at a professional level, and he is constantly testing and reevaluating his work. Having a good rolling testbed for this testing can be useful, and his tricked out KTM 450 EXC serves that purpose dutifully while also being a whole lotta fun on and off the road.
“I love this KTM,” Schmidt said. “I bought three years ago. It was lowered and really beat up but, I got it cheap. I rode it for a year, then the counter shaft bearing went bad and that is where the project began.”
Enlisting the help of Southern California dirtbike project guru Jay Clark of Jay Clark Enterprises, Schmidt tore the KTM’s engine completely apart and inspected it. Aside from the errant countershaft bearing, everything else was in excellent shape. But since he already had it apart, he buttoned the engine back up with a Vertex Pistons Replica piston kit, which includes the piston, rings, pin and clips. The Vertex kit doesn’t really count as a “mod” since Vertex is the OE supplier of KTM pistons, but the Italian-manufactured pistons are a popular replacement choice for a variety of dirtbikes.
“I couldn’t put it back together with the same piston and valves, so the top end got new parts and the whole engine got a good scrubbing,” Schmidt said.
The engine now breathes clean air through a Uni Filter two-stage air filter. For added power, Schmidt left the stock camshaft alone but slapped on an FMF PowerCore 4 slip-on exhaust system. Other dress-up items for the engine include CV4 formed silicone coolant hoses, while a Trail Tech radiator fan and CV4 high-pressure radiator cap help to keep the coolant in the engine where it belongs. A Tusk Off-Road oil filter was used to keep the engine oil clean on long off-road treks.
With the bike completely torn down, the chassis was treated to a thorough sandblasting by San Diego Powder Coating, which also applied an orange powder coat with superdurable clear, and “race prep masking.” Pivot Works supplied a new steering stem bearing kit to help the KTM steer to its potential. Speaking of steering, the handlebar is a Renthal 604 Fat bar with Kevlar grips. For extra hand protection while on the trail, Schmidt also installed a set of Tusk Off-Road’s D-flex handguards with a fat bar adapter kit. Tusk Off-Road clutch and brake levers and a Tusk Off-Road shifter replace the stock KTM parts. Other dress up parts include a new front brake cap and clutch master cap from Works Connection.
For added range, an IMS 2.9-gallon fuel tank replaces the stock unit, while improved lighting comes via a Trail Tech X-2 headlight powered by a Tusk Off-Road Lithium battery which also supplies the juice for the KTM’s electric starter. A Moto Seat Custom Cool seat cover and foam along with IMS Core Enduro footpegs offer great looks and better comfort than the OE pieces they replace. Knowing that he’d need a mirror to turn this off-roader into a street-legal dual sport bike, Schmidt also added Tusk Off-Road Double Take enduro mirror. The KTM’s plastic is all-new, including a Polisport full plastic kit with an updated front number plate and fender. An Attack Graphics custom graphics set gives Schmidt’s KTM an off-road racebike look.
One area where Schmidt saved some money was with the KTM’s suspension. Naturally, being a suspension man, he did all the work himself.
“The old WP open bath fork is amazing,” Schmidt said. “WP has used a similar version of this fork for decades and even up to 2016, so just the right springs and a good valving spec were needed. The rear, being a linkless PDS system, needed a little more creativity. We went with a Progressive spring to add more progressiveness to its very flat curve, along with a bladder conversion kit to make it more forgiving on square-edge bumps. We also added a Hi/Low speed compression adjuster off of a newer 2014 model to give us more adjustability, and matched it with a creative valving spec to help it be more compliant over roots, ruts and rocks. Now, on a two-, three- or four-day ride, it won’t wear me out.”
Schmidt said that one of his major concerns was having a machine that featured optimum gearing for tight and technical off-road sections while also being able to cruise comfortably on the highway. After testing it, he now has no worries.
“With the 14/52 gearing the previous owner had on it [which is actually two teeth tighter than the stock 14/50] the bike is impressive,” Schmidt said.
The 14/52 cogs are from Renthal, including a Twin-Ring rear sprocket held in place by a Tusk Off-Road sprocket bolt kit and a new countershaft sprocket with a Dirt Tricks countershaft dome washer. A beefy TM Designworks chain guide helps keep the stock chain in line when the going gets rough. Tusk Off-Road wheels with black rims and orange hubs replaced the stock wheels, and Schmidt went all-out by adding a 270mm front rotor and adaptor bracket with a Tusk bolt kit, Tusk brake lines, Renthal brake pads front and rear, and a Tusk rear brake pedal. The tires are Dunlop’s excellent AT81s in sizes 90/90-21 in front and 120/90-18 out back.
Schmidt let DirtBikes.com swing a leg over the bike for a basic riding impression and some photos at the Wildomar OHV Park in Orange County, California, and we let test rider Nic Garvin spin a few laps around the secluded, tiny facility. Garvin came back impressed.
“It’s a lot of fun,” he said. “It just shows what you can do with one of these older KTM’s. The power is strong, but it’s easy to ride—tractable and not super-aggressive. It doesn’t wear you out. If I had a dual sport bike, I’d want something like this because with the suspension and motor mods, it’s truly off-road worthy while still being street legal. I think he did a good job with the parts he added to the bike.”
Schmidt adds, “It has everything I need. It makes good power down low to get out of the tightest places and it has more than enough to do 70+ on the highway. With the added power it’s even better.”
Schmidt Performance/Vertex/FMF KTM 450 EXC
Vertex Pistons www.vertexpistons.com 515-270-2302
Pro Replica Top-End Piston kit (ring, pin and clips)
Attack Graphics www.attackgraphics.com 801-465-4382
Custom Graphic set
FMF Racing www.fmfracing.com 310-631-4363
PowerCore 4 Slip-On exhaust
Pivot Works www.pivotworks.com 515-402-8000
Steering stem bearing kit
Polisport plastic www.rockymountainatvmc.com 800-336-5437
Full bike Plastic kit Updated front # plate and fender
Pro Moto Billet www.promotobillet.com 866-466-4762
Uni Filter www.rockymountainatvmc.com 800-336-5437
Two-stage Air Filter
CV4 www.cv4.net 800-874-1223
Formed Silicone Coolant hoses
High pressure radiator cap
Renthal www.renthal.com 877-736-8425
52T Twin Ring sprocket
604 Fat bars
Front and rear brake pads
Dunlop Tire www.dunlopmotorcycle.com 800-845-8378
AT81 front 90/90-21
AT81 rear 120/90-18
Moto Seat www.motoseat.com 951-258-5229
Custom Cool seat cover
Works Connection www.worksconnection.com 800-895-8292
Front brake cap
Clutch Master cap
Tusk Off road www.tuskoffroad.com 800-336-5437
270mm Oversized Rotor/Adaptor Bracket 270mm
Complete Wheel set- Black rims/Orange hubs
Brake bolts kit
Sprocket Bolts kit
Rear Brake Pedal
Front and Rear Brake lines
Front Brake lever
Tusk D-Flex hand guards with fat bar adapter kit
Tusk Lithium Battery
Tusk European Bolt kit
Double Take Enduro Mirror Kit
Dirt Tricks Countershaft Dome Spring Washer
TM Designworks www.tmdesignworks.com 541-772-4161
Rear Chain Guide
Trail Tech www.trailtech.net 360-687-4530
X-2 Head light
Rocky Mountain ATV/MC www.rockymountainatvmc.com 800-336-5437
All OEM parts— KTM Frame guards and Skid Plate
O-ring Chain from Primary Drive
IMS Products www.imsproducts.com 800-237-9906
Large Fuel tank 2.9
Core Enduro Foot Pegs
San Diego Powder Coating www.sandiegopowdercoating.com 619-956-0987
Sandblasting, orange powdercoat with superdurable clear, and “race prep masking’
Schmidt Performance www.schmidtperformance.com 951- 251-5133
Schmidt Performance Revalve/Update Mod for Dual Sport/Single Track
(Allows the wheels to better track the ground when hitting rocks, rain ruts and roots)
Maxima Suspension fluids
Seals and bushings
4.8 kg Fork Springs (the right spring rate to holds the bike at the proper ride height)
8.5/11.0kg Progressive Shock Spring
(The right spring rate to put the bike at the right ride height while adding a more of a progressive curve into the linkless system)
Shock Bladder System
(Converts the plastic floating piston in the shock reservoir into a bladder system which moves easier allowing the shock to be more compliant)
Shock Rebound Housing
PDS Rebound adjuster Housing seals the rebound adjuster to prevent debris from seizing the adjuster
OEM KTM 2014 500 EXC Shock Compression Adjuster with low and high speed adjustment (ordered thru RMC oem parts)
(Helps keep the rear of the bike from blowing into the stroke too fast without having to over compensate with valving or spring rate)