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2004 Suzuki DR-Z440

Tuesday, March 16, 2004
2004 Suzuki DR-Z440
Reverse Psychology

When most people think of building the ultimate dual-sport machine, they typically envision street-legalizing one of their favorite off-road or motocross bikes. Most people call a company like Baja Designs, order up the dual-sport kit for their favorite 4-stroker, install it, get their plate from the local DMV, and are set to rock.

Wiseco's Jay Clark used reverse psychology to attack the dual-purpose situation, building one of the trickest dual-sports we have ever seen. He took Suzuki's already street-legal dual-sport machine, the DR-Z400S, and threw an entire parts catalog at it before setting it loose on the trails of Southern California and Colorado. It's a good thing he works in the industry, because this bike might have cost him a second mortgage on his house had he been a regular "Bob" like the rest of us.

If you've ever wondered about all the different aftermarket accessories and modifications that are out there for the DR-Z series (or just about any dual-sport or off-road bike), look no further than here for ideas.

Last year, MotorcycleUSA's Brian Korfhage tested the off-road version of the Suzuki DR-Z400E, and came away quite impressed with it, praising the bike's good, usable power in any gear, nice enduro amenities, quiet exhaust note, and large fuel tank (2.6 gallons). At the same time, the bike had some low points, which were a heavy overall weight of 262 pounds, soft suspension components, and an unpredictable front end. The DR-Z400S is basically the same bike with an additional 30 pounds in weight from the metal fuel tank, passenger pegs, blinkers, horn and other dual-sport necessities. The bike also has a 3mm-smaller CV carburetor (36mm). Jay had managed to jump through the regulatory hoops of getting the bike a license plate (which is now impossible in California as of January 2004), but now had to alleviate some of the weight and power penalties he induced by starting with the heavier street-legal bike.
2004 - Suzuki DRZ440 - Project Bike

Jay had the obvious goal of trying to lighten his streetbike, while at the same time improve the power, make the suspension better able to handle tough conditions, and finally, make it really trick. With many connections to the industry, it wasn't too much of a problem for Jay to achieve these goals,  just a lot of phone calls and deal working.

Aftermarket Accessories and Modifications

The heart of this machine is its modified engine, beginning with a Wiseco 440cc kit that DSP installed. The piston is 94.5mm and 13.5:1 compression. In order to handle the bigger piston, the stock DR-Z cylinder is bored out and a new aluminum sleeve is installed after receiving a Nikasil coating performed by Millennium Technologies. Wiseco sells the cylinder, piston and Cometic gaskets together in one easy kit.

For better airflow, DSP worked on the cylinder head and switched the stock S-model CV carburetor to a Keihin flat-slide 39mm carburetor like the ones that comes stock on all the 450cc MXers. They also matched the carb to one of their Power Now kits and re-jetted everything to match the bigger bore and headwork. DSP also opened up the airbox drastically on the top and sides of the box before installing a freer-flowing Uni Filter air filter.

2004 - Suzuki DRZ440 - Project Bike
The Wiseco 440cc kit includes the cylinder, piston, and Cometic gaskets.
To improve clutch durability and performance, a Wiseco forged clutch basket was used. George at DSP uses Hot Cams camshafts and likes the tunability that they provide, so two of those (intake and exhaust) were also installed before closing it all up. A complete FMF Q-Series exhaust system featuring a Power Bomb header finished off the motor to provide more power, yet remain rather quiet for the trails. When all was said and done, the DR-Z440 was putting out close to 50 horsepower.

The suspension was turned over to Race Tech where an inverted RM250 fork was matched to Applied triple clamps. The fork and the shock were re-valved with Race Tech's Gold Valves to match Jay's weight and riding terrain. The fork also got the trick titanium-nitride coating on the lower legs like works units. Switching a fork is a major job and, unfortunately, cost-prohibitive for most. The work required to hook up your controls, lights, speedometer and cables is somewhat extensive. It requires serious custom work by the installer. However, the improvement in suspension performance is astounding, and this motocross-sourced RM250 fork is one of the sweetest items on the bike. A cheaper route is to have Race Tech make similar improvements to the stock conventional unit fork.

A Scotts Performance steering stabilizer was installed to further the handling improvements up front, and it was mated to a set of Renthal's Fat Bars. To increase the power from the front brake, a Ride Engineering steel-braided (and much shorter) front brake line was fit. A Works Connection pro clutch perch and lever with a quick-adjust feature, and Cycra Pro-Bend handguards finished off the control modifications. 

2004 - Suzuki DRZ440 - Project Bike
A Scotts Performance steering stabilizer helped handling up front.
An IMS 3.2-gallon tank was installed to extend the fuel range considerably on long journeys. IMS installed a very cool custom breather on the tank to allow a straighter shot for the breather line to run down. IMS also hooked Jay up with a set of big and beefy Pro Series pegs. UFO front and rear light assemblies that have the turn-signals embedded in them were installed to reduce weight and keep the blinkers safe in crashes. Acerbis provided the rear-fender brace, side panels, and mirrors for the dual-sport weapon. Ceet was responsible for making the graphics, along with providing a new seat cover with different foam underneath to make the ride more comfortable on long treks.

When it comes to protection, this bike has no shortage of it (perhaps Jay crashes a lot) and much of it seems to be made of high-strength, super-light carbon fiber. This bike has more guards than Alcatraz. A Carbon Factory chain guide and clutch cover (with a Baja Designs aluminum outer-clutch cover protector) were installed for added protection along with DSP's carbon fiber skid plate, engine guards and frame guards. The only guard it has on it that isn't carbon fiber is the aluminum side-case shield on the ignition cover, which is from CFC Off-Road.

The passenger footpeg mounts were left on for Clark's seven-year-old daughter who insisted they not be removed. However, some material was cut off. One of the peg mounts also serves as a pipe bracket, and there are aftermarket brackets available if you wish to get rid of the extra pegs and their weight. In an effort to reduce more weight, the plastic chain guard fling-flapper and the aluminum mounts on the swingarm were removed. The black plastic oil canister was also tossed in favor of a more direct routing of the oil lines to the air box.

2004 - Suzuki DRZ440 - Project Bike
Aftermarket signals were utilized in the front and rear to save weight.
The stock street meats were tossed (very far) in favor of Dunlop 756 tires and heavy-duty tubes. They're not quite street legal (DOT) but, then again, Jay doesn't use the street that often,  only to connect trails. Finishing off the drive system were Sunstar Sprockets and a Regina O-ring chain for increased durability and reduced weight. And finally, the last set of modifications Jay could possibly think of was the use of Pivot Works bearing kits throughout the bike (wheels, steering stem, shock linkage and swing arm). Yes, this bike is crazy! Basically, Clark modified every part of the bike except for grabbing a new frame and swingarm. If he gets any more ideas, BBR could be getting a call any day, which would, hands down, make it one of the most expensive dual-sports ever built. As it stands this thing has to be worth over $10,000 right now! 

Performance On The Trail

This bike can be described in one word: awesome. The powerplant is a huge step up from your typical DR-Z. It climbs with ease and is able to pull third and fourth gears up the huge, sandy, and technical hills of the Jawbone Canyon/Dove Springs OHV areas in Southern California. The motor has plenty of power to attack any hill-climb with confidence. In fact, the motor is now comparable to the latest crop of 450cc MXers out there. It doesn't hit quite as hard or have as much overall power as the uncorked MXers, but it's darn close. That's impressive considering the bike's corked-up exhaust system. This is now a machine that hits hard with a massive improvement to the midrange and top-end power, and plenty of low-end power has been added where it really needed help.

2004 - Suzuki DRZ440 - Project Bike
The modifications transformed the normally mild mannered DR-Z to a snorting beast.
Even with the Q-Series exhaust, it's still probably borderline loud for some sensitive areas, but it should be fine in most other places. If you live in one of those areas where you have to be quieter, running the stock exhaust with one of the aftermarket baffles is the ticket, and you'll still love the added power of the big-bore kit. We recommend it to all DR-Z400 owners who want more power.

The transmission, on the other hand, was still the same as stock, and that means occasional missed shifts and an overall vague feel to the shift lever. We seemed to experience a few more missed shifts than normal with all of the motor mods, which probably could be attributed to the added power output, higher revs, and harder riding the bike is now subjected to.

The suspension performance is one of the best things about this bike. It's extremely plush, and by that we mean one of the plushest we have ever felt. It handily soaks up large G-outs yet is still compliant over high-speed chatter. It handles big whoops and jumps with ease, and the small chop that can sometimes induce headshake is calmed down by the Scotts steering damper. The bike's handling is very predictable, as you can attack whooped-out corners with confidence and not worrying about getting swapped out in the turns. It doesn't feel or fly like the 450cc motocross bikes we keep comparing it to, but you have to keep in mind this is a street-legal motorcycle. The Race Tech suspension definitely makes this dual-sport a great ride.

The front-braking power is greatly improved with the shorter, steel braided cable from Ride Engineering. It makes stopping a heavier bike like this that much better. The ergonomics and controls feel perfect, and you just know it's going to take quite a crash to stop this bike from getting you back home with all of the extra protection offered by the stronger and lighter bars, skid plates, hand guards and numerous carbon fiber goodies.

2004 - Suzuki DRZ440 - Project Bike
Engine and exhaust modifications drastically improved the midrange and top-end power.
The only bummer about this bike is that it is still a tad heavy. It's definitely lighter than a stock version, but still weighs more than the dirt-only DR-Z400E, which puts it around 280 pounds. That's roughly 40 pounds more than a 450cc motocrosser. We figure most dual-sports on the roads weigh anywhere from 240 to 325 pounds (including kitted bikes and modified OEM dual-sports), so that puts it right in the middle. That's not too shabby for a bike that started out as a streetbike. The only time you really feel the extra weight is when you're walking it around the garage or in huge G-outs. The improved suspension and motor performance make up for any shortcomings due to weight.

We could have easily entitled this story "The 50 Top Aftermarket Products for your DR-Z/DR-ZS." This bike is simply awesome and a one-of-a-kind. Buying a DR-Z is one of the few ways Californians can ride a dual-sport since the DMV will no longer issue plates for newly-converted bikes as of January 2004.

Is all the time and money worth the cost? Yes and no. If you're hooked up like Jay, then, hell yes it's worth it! It rips, it's lighter, it looks phenomenal, and it handles very well. If you're the average Bob then, no, you shouldn't build a bike like this unless you want a divorce (man, my conscious is wondering how many families may be broken up over this story). But any combination of these parts could grace a man's (or woman's) ride depending on what aspects you are looking to improve. Happy trails.


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Comments
Punes Tepist -fork conversion  May 28, 2009 04:00 AM
Hi, hopefully you figured it out already since Feb, but if not I suggest the easiest and cheapest solution is to use the DRZ400SM suspension. As the frame is the same and the fork is from rm250 just as in the article. Or just sell it and buy the SM. It has the RM250 rear fork and suspension too. Chuck the enduro wheels and tires in and your ready. Good luck!
Joe M -fork conversion  February 10, 2009 11:17 AM
I have a 2006 Suzuki DRZ 400E, and want to convert the front end to inverted forks just like the one on this article. what year inverted forks from an RM can I use, and and which triple clamps do I need, RM or DRZ? thank you all for any answers.