So, you want to rally your DR650, eh?

Where it all began….

Suzuki’s iconic backcountry bike has been with us in one form or another for more than three decades. Unchanged (for the greater part). Think. There are some buyers of this piece of motorcycling history who weren’t born when the first of this line began to be made. There might even be someone riding a DR that is older than they are….

Declaration of Interest: I like these bikes. I have two, I have worked on many and others. I run a motorcycle rallysport company. I live in possibly one of the best places to ride dualsport bikes - Vancouver Island. I have a vested interest.

I won’t go on about the history as that can be found easily if you are interested and not particularly relevant to this particular tale about how to prepare a DR for motorcycle rally riding if you are not.

What I will concentrate on is the sense and sensibility of using a DR as a rally bike.

To choose to start with a DR or not….?

Like all motorsport, your choice of vehicle with which to campaign depends on factors that may not be entirely within your control…. Finances. Regulations. Availability. Marque loyalty…

To address the headline question, “can you rally a DR650?” the answer is “well, yes and no, it depends…..”

Depends on what, exactly? Can you use a DR according to the regulations of the event(s) you plan to enter?

• The FIM (Fédération Internationale de Motocyclisme) is the world governing body for motorcycle motorsport. The FIM world Rally-Raid championship regulations stipulate a maximum engine size of 450cc.

So, no DRs at FIM events….. But

• There are plenty of other motorcycle rallysport events that are less restrictive on engine size, both in Europe and North America.

So yeah….

Having either chosen events to suit your bike choice or chosen your bike to suit your event choice you can now move on to your next level in this decision making process.

• Performance potential. The DR is an old design that hasn’t changed hardly at all over it’s (continuing) production run. There is nothing “cutting edge” about it! If your riding is of a sufficiently high standard to be in the running for a top-of-the-table finish, there are more modern machines on which you are more likely to achieve success, but let’s assume a top-of-the-range competition off road bike is beyond your reach and continue our journey down this particular rabbit hole.

The Good, The Bad and the Fugly…

As they come, out of the box, covered in cornflakes and bubble-wrap, your bog-stock DR is perfectly appropriate for a life commuting and town riding but probably wouldn’t make it past the first five miles of an off-road event.

Let’s go through things, one by one with remediations and costs. In no particular order…

Even with only 100km on the clock, the transformation has begun

• Engine and gearbox. DO NOTHING! You cannot improve these basic components. Well, you could fit a big-bore 750cc conversion and a six speed gearbox for megabucks - but why?

  
  

• Final drive. As they come, DRs come with a final drive gearing that is a little on the high(way) side. It works well on tarmac but off-road the gaps between the gear ratios can be a little wide and first gear can be a little tall. Easily rectified by swapping the gearbox sprocket for one with one tooth less and changing or modifying the keeper washer that locks the sprocket to the output shaft.

  

  

  

  15 tooth sprocket with retainer compared to 14 tooth with smaller retainer

  
  

• Carburation. As they come, DRs are jetted on the lean side of lean in order to meet the stringent emission regulations we are blessed with. It is necessary to change the carburetor jets and needles in order to richen the fuelling and also make some straightforward air box modifications. Unfortunately the fuel consumption increases…. Jet kit costs $150

  
  

• The factory carburetor is a 40mm constant vacuum Mikuni. Itself a masterpiece of carburetor technology (some might disagree). And people love to mess with them! Usually without knowing too much about what they are doing. CV carbs are designed to make controlling the engine with the throttle easy. You can wind the throttle fully open very quickly and the carburetor will only open up to deliver air/fuel as quickly as the engine can handle. Mess with the damping of the movement of the air slide or the spring that controls it and you will upset the intrinsic accelerator pump action of CV carbs, the mixture will go lean and the problem you tried to solve suddenly becomes worse.

  

  Mikuni BST40

• If you must, fit an accelerator-pump slide carb, get some extra control over the power delivery and have your fuel consumption take a further hit. See my next point…. Slide-pumper carbs cost between $400 and $800 plus workshop costs if you don’t do the work yourself. You won’t turn your 650 into a fire-breathing 800 killer. Its maximum power will remain unaltered.

  

  

  

• Fuel tank. The stock fuel tank is small. Address the lean carburetor settings and the modest range afforded by the small tank gets much smaller. Fit a pumper carb and the modest range gets to be a severe handicap. Fuel consumption can be 30-35 miles ( x 8/5 for kilometres) per imperial gallon (4.54litres). I’ll let you do the maths….. There are large capacity fuel tanks that are easily available and double the fuel capacity. The tanks cost in the region of $400 to $600 and 25litres of 93 octane weighs approximately 25kg!

  
  

• Exhaust. The factory exhaust is a miracle of engineering. It is shiny, made of stainless steel, very quiet, it is its own spark arrestor and it is heavy, shiny-heavy. There are all sorts of aftermarket options that decrease weight, increase noise and require spark arrestors. They are less shiny. Cost in the region of $500. Or you can dismember the Suzuki exhaust, disembowel it and have your friend weld the shell back together. Your guilty secret! You may have to further “adjust” the carburetor jetting…

  
  

• Wheels, tyres, brakes, seating, footrests, handlebars. Let’s take the tyres first. The Original Equipment tyres are the much-maligned Trail Wings. Vehicle homologation and type approval demands new vehicles be quiet. It is relatively easy to arrange for a quiet exhaust and intake noise, it is even possible to arrange for an engine powerband hole that corresponds to the drive-by noise test speed to further quieten the bike under test conditions. That leaves tyre noise as the major contributor to vehicle noise. Trail Wings are specifically designed to be quiet when used on tarmac and they are given a tread pattern to resemble off road tyres. Just because they look like they will do the job doesn’t mean to say…. If you continue to ride your DR on tarmac you probably won’t encounter their performance limitations. Go seriously off-road and you will want off-road tyres. Your choice.

  
  

• Wheels might need rimlocks, if you are planning on riding at highway speeds - especially over potholed gravel roads you will need to carefully think about what tyre pressures you are going to use. One of the “conventional wisdoms” is to air-down when going off road to allow the tyre maximum opportunity to deform over irregularities and maximise grip. At slow, trials or hard enduro speeds this seems sound advice. Hit a pothole at 100kph with 10 lbs/squinch and something is going to give (like a tube, a rim or spokes). The other “conventional wisdom” is to run tyre pressures according to the speed to are going to ride at. The various devices to eliminate inner tubes either don’t come in 17” rim sizes, don’t run at highway pressures or can’t be run for long distances at highway speeds. It seems that Mr. Dunlop’s pneumatic inner tube is likely to be with us for some time yet.

  
  

• Brakes don’t need improvement, just careful maintenance, seating handlebars and footrests are mostly a matter of personal choice.

  
  

• Suspension. Now we get to the heart of the matter. As they come, DRs are adequately suspended for road use. Go off road and go swiftly and you will quickly discover that the factory settings are under-sprung and under-damped. The heavier you are and the faster you go the worse this situation is. If you are competent with the tools, you can fit damper valves and stiffer springs to the front suspension, a stiffer spring and re-oil the rear damper yourself for less than $1000 all told. If you have to pay someone to do this it might cost three times as much. Go with yet more exotic suspension components and the cost will be correspondingly higher. Suspension upgrades seriously improve the bike though. Probably indicating how basic the factory settings are…

  
  

• Navigation accessories and power supplies. You don’t need a rally navigation tower, you can manage with a handlebar phone mount. Get a little bit serious though and a tower with all the electrical additions like usb chargers and bespoke electronic hardware mounts become performance enhancing features. How much can all this cost? If you buy and have someone fit it can cost thousands. If you build and fit yourself you can spend just a couple of hundred dollars/pounds/euros. Comes back to your budget and how badly you want to achieve….

  

  The budget end of the navigation tech market. You can spend thousands…

  
  

• Antilock brakes, traction control, fuel injection. These bits are easy to deal with - I’ll let you work out how to.

  
  

• The alternatives.

  KLR 650. Kawasaki equivalent of the DR with added bodywork and liquid cooling. A little less of an Armageddon bike.

  DRZ 400. Suzuki. Also liquid cooled. More expensive and the new version comes with fuel injection and antilock brakes.

  Honda CRF and XR650L. Limited availability in Canada, the CRF450RL is available in Canada and is more expensive than the DR.

  Kove 450. Kosher Chinese road-legal rally replica. Serious kit for an affordable price.

  Royal Enfield 450 Himalayan. Also affordable and seems to be Royal Enfield preparing to take a shot at FIM world events.

  CFMoto 450 Ibex. Another Chinese bike, apparently poised to qualify for FIM events.

There are many choices to be made based on the events you might have in mind, your budget, your brand preference, tariffs, availability, blah, blah, blah.

Most likely, your decision to use a DR for rally riding will mostly have been made for you, dictated by your budget or the fact that you already have one. They can be developed into a reasonably capable “clubman” rally bike that won’t cost your children’s inheritance to build and run, will be reliable, rugged and straightforward to use and possibly most importantly, if you are riding navigation-trial Regularities rather than speed RallyRaids, the results are 95% rider skill in navigation.

What an exciting time to be riding these kind of bikes! Sport For All